Baltimore's Key Bridge struck by cargo ship, collapses | Hacker News Reader

Baltimore's Key Bridge struck by cargo ship, collapses

wbaltv.com

712 pointsQuarterReptile1,108 comments

Youtube tracking analysis from a knowledgeable mariner.

He says that at about 1:24 AM the ship loses power (from video feed) while traveling 8.5 knots.

at 1:25.30 power is restored.

at 12:25.59 the ship shows smoke. The ship has already drifted in the channel. It is believed that at this time the ship applied full reverse power as evidenced by the black smoke. (My analysis: the ship drifted but hasn't turned in the channel, more of a translation)

By 1:26.45 the ship has obviously turned in the channel pointing at the pier. Full reverse would cause prop walk to change heading angle;

1:28.52 impact at 7.6 Knots. Camera says 1:28.52, AIS reports the ship still moving at 1:29:35

https://www.youtube.com/watch?v=N39w6aQFKSQ

Does that mean this was effectively captain error? Like in response to a power outage the decision was made to try to reverse and rather than arrest forward momentum it just pushed their forward vector into the piling?

I would tend to think so. The pilot should have anticipated prop walk and known that the ship had no chance of stopping before the bridge.

I’m trying to find a color coded current map. Wind too. I wouldn’t expect wind or current to cause the pronounced heading change that is visible. The drift seems possible.

Note: I’m an experienced dinghy/keelboat sailor, but lack virtually any experience driving boats under power, much less commercial vessels

yeah, noted. But it does seem like the heading change was so dramatic and the smoke pouring out after power recovery that something happened with the prop. And while it may have been currents, the lack of heading change before the smoke seems to suggest there was an intervention that caused heading change.

Ship travel, much like orbital mechanics, are so often non-intuitive if you're not familiar with how much effort it takes to make significant speed changes vs. heading changes. And speed changes often affect the heading as well if you're not careful.

It seems the excellent windy.com has wind and current data from the incident still available. Looks like current was <0.2 kts and wind was 6 kts south-east. So both should be completely negligible.

Checks out.

.2knots/hour = 405 yards/hour

It was 4 minutes from power loss to impact.

405 yards/15 = 27 yards. And that's if the ship instantly accelerated to a 0.2 kt drift, which it wouldn't. Wind acceleration on the vessel than current.

For some reason, I thought that large vessels hired a local pilot to navigate their way through places like this.

Captain, or pilot? In Baltimore, as in most harbors, a local pilot comes on board to guide the ship. Is this their responsibility?

I too, have read about Baltimore pilots for the first time today. If you’d read a bit further, the Pilots use either intercoms and sometimes radios to send instructions to the captain while they’re elsewhere on the ship. If they were using intercoms, and there was no power, that would do it

> In Baltimore, as in most harbors, a local pilot comes on board to guide the ship. Is this their responsibility?

I would doubt the pilot would have ordered the power to the ship to be cut and for everything to go dark right before hitting the bridge. Pretty sure they were probably telling them to navigate away from the pylon.

Yes, they have the responsibility, not the captain, as evidenced by the specific insurance they carry.

Of course, lawyers will try to spread the blame around (who chose the pilot, did captain's actions or orders somehow get in the way of the pilot; did captain not ensure engines were working properly...). But the base responsibility lies with the pilot.

It probably helps the captain that this was a ship owned and operated by a very big vertically integrated company (Maersk). Most ships are owned by smaller companies with a few (10-150) hulls and then chartered out. And while in this case the ship was chartered (along with crew) I bet Maersk's systems are stronger than your average charterer's.

I thought the pilot only offered “guidance” to avoid responsibility. I learned that from a documentary on the Panama Canal.

Is that just a Panama Canal thing? Or should I find better documentaries?

https://en.wikipedia.org/wiki/Maritime_pilot

Panama is the exception

> Legally, the master has full responsibility for the safe navigation of their vessel, even when a pilot is on board. If they have clear grounds that the pilot may jeopardize the safety of navigation, they can relieve the pilot from their duties and ask for another pilot, or, if not required to have a pilot on board, navigate the vessel without one. In every case, during the time passed aboard for operation, the pilot will remain under the master's authority, and always out of the "ship's command chain." The pilot remains aboard as an important and indispensable part of the bridge team. Only in transit of the Panama Canal does the pilot have full responsibility for the navigation of the vessel.

You might have misunderstood the difference between controlling the ship and commanding it. The Panama Canal Authority pilot controls navigation and maneuvering to get through the canal but the captain is still in command of the vessel and ultimately responsible for it.

Canal accidents cost so much that they're each individually investigated and insurance companies fight over who is liable. Sometimes it's the pilot's fault and ACP's insurance pays out, sometimes it's the shipping company's insurance, and sometimes they split the cost.

This news report [1] confirms there were two pilots at the time of the accident. Baltimore Port runs a dock pilot from the Key Bridge to the port itself, and after the Key Bridge, a harbor pilot who takes the ship (I believe the rule is any vessel > 100 tons, and all non-domestic ships of any tonnage must by Maryland state law be piloted in this manner) out to the mouth of the bay.

The after-accident report and insurer and re-insurer wranglings will be a fascinating read, I'm sure. It will be a miracle if the taxpayers escape unscathed for the rebuilding of the transit spanning the harbor, and it falls entirely upon the insurers and re-insurers.

As dramatic as this accident was though, and the many parallels I can draw from its lessons to software engineering, IT operations, cybersecurity and so on, I'm not as sanguine believing it will really drive home to organization leaderships the evergreen advice to pay down your tech debt, maintenance matters, organizational culture/esprit de corps counts, the operational teams are just as important as the engineering teams, etc.

[1] https://fox59.com/news/national-world/cargo-ship-hits-baltim...

How common are power outages on ships? I get that the captain might not have responded to it correctly but that seems like a thing that shouldn't happen, at least in my completely uneducated opinion.

It shouldn't happen. There will be investigations. I think that having a properly operating ship is the captain's responsibility.

But the ship's pilot [1] (not captain) should know exactly how the boat will handle and the exact course of action. Pilots are extremely well paid ($200-$400k) and the tests are very stringent. Friends have told me that the Narraganset Bay pilot test involves drawing every shipping navigation bouy on a map by hand to within ~200 yards from memory alone, compass, ruler and scaled map provided.

Where do you get those salary numbers from? The info about this "Dali" ship is not private: [0], and it lists the master's salary as $10,200 per month.

[0] https://www.balticshipping.com/vessel/imo/9697428/seafarers

The pilot is employed by the port/government, not the ship. They drive to just outside the entrance, then they get off onto a tugboat or some other small utility vessel.

Harbor pilots are licensed by the state (Maryland) require a degree from one of the maritime colleges, deck license, …, are represented by a pilots union (Association of Maryland Pilots) but are employed independently.

I believe the parent comment is referring to the harbor pilot job specifically.

https://en.wikipedia.org/wiki/Maritime_pilot#Compensation

> The Florida Alliance of Maritime Organizations reported that Florida pilots' annual salaries range from US$100,000 to US$400,000, on par with other US states that have large ports. Columbia Bar pilots earn approximately US$180,000 per year. A 2008 review of pilot salaries in the United States showed that pay ranged from about US$250,000 to over US$500,000 per year.

Columbia Bar pilots are grossly underpaid.

Having visited the Columbia River Maritime Museum (I would strongly recommend if there) https://www.crmm.org - that is 100% correct. Its a place that they send other pilots to do things like rough water training.

In this case, a seemingly pedantic distinction matters:

Pilot != Master

Pilots are very highly paid

According to this book: https://www.amazon.com/Tankship-Tromedy-Impending-Disasters-...

It is quite common and vessels often have outages that leave them Not Under Command. Usually they are safely at sea when this happens and they can drift for hours without causing problems. But of course there's always a possibility of it happening at exactly the wrong moment.

The reasons for this are the usual: lack of redundancy, lack of maintenance, overworked and understaffed crews, etc. etc. The book lays out how ships are pretty much designed to be floating disasters and the Class societies (essentially privatized regulators) are in the pockets of the builders, and they are so captured that they make rules that make it difficult to make safe vessels.

For instance, he was trying to design multi-screw vessels but the rules now assume single-screwed ships and it can be impossible to design in additional shaft alleys and still conform.

It wouldn't help with this accident, but you would think that the electronics would be on batteries. It wouldn't be too hard to have rack of batteries that would power the lights, instruments, radios, and sensors. Doesn't help if the propulsion or steering go out, but does make easier to know whats going on.

At least in small craft, bow thrusters are usually electric, with local batteries charged from the main engine room. I don't know what large craft are like, but it doesn't seem unreasonable that a bow thruster may remain operable even if the main engine fails. Clearly that's not required or they would've had it and used it, but it could be required if the regulations didn't suck.

Furthermore, steering could absolutely have an electric backup for the hydraulic pumps that power the main steering gear. As long as there's some forward speed through the water, the rudder should work. But again, backups clearly aren't required or they would've worked here.

Steer-by-wire cars are required to have all sorts of redundancy so they're almost as safe as steering-shaft cars in case of an engine failure. This is a 9,900TEU ship with a 41480 kw powerplant. That a ship with so much more destructive potential is allowed to operate without the same level of redundancy as a $90k Audi, is unconscionable.

The difference for a car and drive by wire system is that the failure mode of control systems on cars is normally catastrophic and dangerous. If a car loses steering or brakes, it will hit something within seconds 95% of the time.

That ship spent 1 (4:30 to 5:30) hour of a presumably 10-20 day voyage in a critical control section. The tugs left the ship right around 5:08 (43 seconds into the video). A much better policy for this case would be to have required the tugs stay with the boat until it passed the main span safely.

There were no doubt maintenance issues that led to this accident, but it is exceedingly rare for these types of failures to cause this type of catastrophic result.

Damage is less likely, but much more destructive. Same as for a nuclear reactor.

It’s not clear why adding ~$100k to the cost of a billion dollar ship is unreasonable

Aircraft carriers are billion dollar ships, these are not. The most expensive container ship tops out at ~$250 million and the one that crashed today is more like $80-150 million. The propulsion systems on these vessels cost tens of millions. $100k wouldn't even pay for the material costs of a rudder.

I don't know enough about the cost and safety tradeoffs made in the design of these ships to comment but your numbers are orders of magnitude off from both directions.

Right. It's not like the ship owners (or, more saliently, their insurers) want things like this to happen.

Second-guessing the marine engineers in this case is like the people post-9/11 who argued that future buildings should be designed to withstand the impact of a wide-body jetliner fully loaded with fuel.

It's basically not a serious argument.

Really recommend you read Tankership Tromedy which was written by a marine engineer. You don't even have to find a copy, the author put a PDF on the internet:

http://martrans.org/documents/2006/safety/The%20_tankership_...

This was written in 2006, so it clearly does not take any data from this incident into account. Even if it were written today, it would not be based on any real data -- it's far too soon for that.

The bridge has been there for nearly 50 years, in a port that handles around 50 million tons of cargo every year.

It seems pretty clear that whatever the cause, it was an extremely rare incident.

You should have browsed the book.

See https://news.ycombinator.com/item?id=39836079

I don't need to browse the book to understand that a book from 2006 can't possibly have any data from an incident that happened yesterday, and that no conclusions can possibly be rendered at this time about the causes of this specific accident.

People are telling you to read the book because, yes, it has a ton of perspective on the long-standing market and regulatory forces that shape the environment that almost certainly led to this specific incident. Understanding how loss-of-power incidents happen, why ships are built the way they are, how flags-of-convenience affect the standards to which ships are maintained and inspected, how ship builders, owners, lessees, operators, crews, and regulators interact, YES, all of those things are extremely relevant to understanding the present situation.

If someone made a landscape painting today using the wet-on-wet technique, would you argue that a Bob Ross episode from years ago couldn't possibly tell us anything about it? That's silly. It's precisely applicable. Mr. Ross himself might not describe the specific location of today's trees or clouds, but he can darn sure tell you how the brush strokes add up to make a tree. Actually he's probably one of the world experts on precisely that.

Proclaiming your ignorance of extremely-well-researched expert sources is not a good look.

Don't be so mule-headed.

While it is true that the investigation into the causes of the disaster is just starting and we don't yet have a definite conclusion, user "jordanb" has done a great service in pointing us to a book written by a domain expert which had pointed out fundamental design flaws in the design of Tankers long ago. Design Flaws have no expiry date until they are acknowledged and fixed properly. In an era of disinformation/misinformation and focusing solely on profits it is important that people be shown some factual data by actual engineers/experts who were very much concerned with safety and how all concerns were flouted by concerned companies/authorities.

Just like the Boeing disasters have shone the spotlight on Civilian Aeroplane Safety, this disaster shines a spotlight on Tanker Safety, arguably a far far more important topic since almost all the world trade of goods and oil is dependent on them exclusively.

> It seems pretty clear that whatever the cause, it was an extremely rare incident.

It may be rare in the lifetime of the bridge, but if there is a variable which has change (or is moving) then that isn't so important a consideration. For example, if container ships have recently become much larger in relation to the design requirements in place at the time of the bridge's construction.

Great resource which allows one to get an idea of the issues involved in Tanker safety. Thank You for posting the link.

Just browsed the book and immediately found "the smoking gun" in the preface itself!

Mandate twin screw in the form of two fully independent engine rooms. Under the current system, 99.5% of all tankers, however large, are single screw. These ships are always a single failure away from being helplessly adrift. The book presents evidence, never before public, that there are at least ten total loss of power incidents on tankers every day. Twin screw, properly implemented, would reduce this failure rate by more than a factor of one thousand. Twin screw would also drastically improve tanker low speed maneuverability which is implicated in a number of big spills including the Aegean Sea shown on the cover.

Neither the insurers nor the owners of the ship will be on the hook for the full set of damages this inflicted.

Thanks to that, they aren't performing an accurate cost/benefit analysis.

While the ship is $200Mish, how much is the cargo also worth? If the ship had went to the bottom in this event the cleanup would take 10x as long and release god knows what pollutants.

Based on what I've read the container ship was only half loaded (5k out of 10k TEU) and most of the containers were empty or lightly loaded. I don't think ships of that size can even navigate those waters fully loaded.

AFAIK the water around the bridge is only like 50 feet deep and the ship itself is about 150 ft high. It wouldn't even really sink, just get stuck on the bottom. A crane ship would come unload it and then tugboats would pull it out.

The worst case scenario though does take a long time if it gets fully grounded and stuck beyond the ability of tug boats to pull it out. A company specializing in marine salvage has to come in to cut it up in place and haul the ship away piece by piece. They use large cutting chains that they pull back and forth to cut through the metal. It's a fascinating process: https://www.youtube.com/watch?v=Ndr2a7AQ8b4

The ship can carry 10,000 TEU, which would fit at least 10,000 imported cars, which would cost around $500mm.

In this case it seems the ship wasn't full, but it's not hyperbole to estimate it as being worth a billion dollars fully loaded. Cars aren't the cheapest things you can ship in containers, but they're far from the most expensive either, and they're what the Port of Baltimore specialises in.

I know this may seem pedantic, but to image that the cost of an additional screw or screw+engine at 100k for vessels like this is patently absurd. Just trying to offer some explanation if you're confused at the responses you're getting. Requiring such a thing would probably have a measurable impact on the global economy, even if all current vessels were grandfathered in and exempt.

Maritime shipping is a business where shaving every penny rules the day.

Most ships use flags of convenience, so the regulatory structure is pretty much nothing.

All valid points. Tugs are quite a reasonable option.

> That a ship with so much more destructive potential is allowed to operate without the same level of redundancy as a $90k Audi, is unconscionable.

Would you still believe this if it was demonstrated that the system lacking redundancy was - due to factors beyond the scope of this conversation - more safe by an order of magnitude than the steering system that includes redundancy but in a different medium?

Put differently: do you think the Space Shuttle should have had ejection seats? If yes, what about an Airbus A320 flying a normal commercial route?

Ejection seats are a use case noche unique to military flying where the pilot is A) the most irreplaceable piece in terms of warfighting, and B) injury of the pilot in the escape attempt is considered an acceptable tradeoff.

If you really want chills, think about this: a conscious decision was made with covil aviation that it was more economically feasible to sacrifice the human lives on board, and resolve the rest through lawsuits.

In short: if you know/are critical to the process of murdering extra-natiomals, you warrant a life saving device.

If you're a civillian, you're a line item in a potential series legal judgements.

That's wrong on so many levels that I don't know where to start. Where in a commercial airliner do you want to keep several hundred explosive devices that would violently launch a passenger out onto an open air, through a hole punctured through a pressurized fuselage at the perfect moment, when the plane could be either at a cruising altitude, over an ocean, or speeding down a runway?

> In short: if you know/are critical to the process of murdering extra-natiomals, you warrant a life saving device.

Do you think it's even feasible to install ejector seats for 10-30 passengers? What do you think will happen if they all fire at once?

Hell no. I'm just pointing out to the other poster that in addition to the fact that military warfighters have a different social calculus in play.

What I'm decrying, however, is our practice of letting actuaries and lawyers be the final arbiters of what is desirable to engineer.

In addition to the other comments:

Military aircraft are subject to failure from being shot at. Aircraft in combat will fail much, much more often than properly maintained civilian aircraft.

Civilian aircraft don't have election seats because situations where they would be useful are exceedingly rare.

The problem is with steering. The rudder on a ship this big is going to be wall of steel several stories tall with gears as big as car.

Warships have several independent backup steering options reducing finally to a worm gear at the top of the shaft with a winch handle big enough to put a gang of men on it. But ships like this will have none of that. They will have a small wheel or joystick on the bridge and if power goes out the rudder will definitely stay in the last commanded position until power is restored. Even if they had auxiliary steering they would not have the crew to man those positions.

This ship would have alternate diesel power plants called "mules" (think APUs on aircraft). It's possible that when the lights came back on that was because they got a mule started.

But really if we don't want accidents like this to happen the ship should have redundancy. A 10,000 TEU container ship is one of the largest and heaviest moving structures ever created by man. Why is it acceptable that it is driven by exactly one engine powering one screw in front of one rudder?

By the way a ship this big with only one screw is very difficult to maneuver at slow speeds. They pretty much have to be going at least 14-15knots to have any rudder authority.

Emergency steering gear is required on every commercial vessel and is regularly tested. We will have to wait for the investigation to see what actually happened.

> But really if we don't want accidents like this to happen the ship should have redundancy. A 10,000 TEU container ship is one of the largest and heaviest moving structures ever created by man. Why is it acceptable that it is driven by exactly one engine powering one screw in front of one rudder?

Perhaps because we have a whole lot of them going and a very low frequency of events like this.

Maybe there's some lighter weight interventions we could do that would further halve the risk of something like this happening that are less costly than fully redundant engine and drive.

They're supposed to have emergency steering gear. Why didn't it work? Maybe ships should have an auxiliary genset running while near land.

> Perhaps because we have a whole lot of them going and a very low frequency of events like this.

This is literally the second major loss of control/allision incident this month.

https://www.tradewindsnews.com/casualties/out-of-control-con...

Seems pretty low to me. How many is too many?

Do we need kindergartens to be safe? How many dead kids is too many? /s

Seriously, in England it is a legal requirement to have redundant brakes on a freaking bicycle. A dude that hit a grandma with a bicycle due to 1 non-functional brake went to prison. But a giant container ship needs nothing?

What is the cost of fixing this bridge and + lost lifetime earning of all the people who dies + compensation to their families? Is that really cheaper than installing batteries plus electric motor?

Now imagine this ship would hit a bridge in daytime, when it’s clogged with traffic?

Cost/benefit analyses are just a fact of life. I see your point, but without really considering the question we don't know what the proper response is. It is not obvious to me that we need to mandate backup power systems, there are an awful lot of ships entering ports around the world each day and very few bridge collapses.

Its not obvious to me either. Let alone the opportunity cost.

The problem is that the bridge collapses that do happen are just catastrophic. The economic impact alone will be massive for Baltimore. But will the responsible parties pay out that damage in full? Unlikely.

Cost-benefit analyses aren't designed to evaluate the total risk a business venture presents to everyone who could possibly be involved; they're designed to evaluate the risk posed by a problem that will launch lawsuits that will play out in courts for years, if not decades. Meanwhile, some injured parties settle for pennies on the dollar, laws change, and in the absolute worst-case scenario, major shareholders draw down their positions in the corporate venture that caused the problem. The world keeps on spinning, and just maybe some regulatory agency will pay attention to the report issued by the likes of the NTSB and USCG.

The process does not adequately protect the public.

Regulations are written in blood, because trying to make everything safe pre-emptively is impossible economically for a number of reasons. Primarily being, you can’t (usually) realistically force people to spend the money on something that isn’t clearly an actual problem.

And that fundamentally means until someone ‘bleeds’/a big enough disaster happens, some things won’t get fixed.

See the triangle shirt waist factory for an example of what it took to be able to force people to pay for certain kinds of fixes.

[https://en.m.wikipedia.org/wiki/Triangle_Shirtwaist_Factory_...]

Since folks aren’t currently burning down the NTSB’s offices or the like, it also seems like your opinion that the public is not currently adequately protected isn’t a majority one?

The only way we’ll ever hit zero accidents is if we are all dead, it’s impossible to do anything without some risk.

I have lived in two different cities where no kindergarten age children have died getting hit by cars outside of their school. Last year I saw a child fall off a raised garden bed at his school, hit his head, and leave in an ambulance. I never found out what happened as I was just visiting that small town.

Children die at or going to/from kindergarten a few times a year I bet in the US.

Late edit: I meant Two** not no.

It’s a legal requirement to have brakes on both wheels of your bicycle. That’s not the same thing as redundancy. Braking performance is significantly reduced if you can only brake on one wheel, so both brakes need to be functional to stop quickly and safely.

And the dude went to prison because he hit and killed a grandma while riding with reckless disregard for the safety of pedestrians. The brake thing didn’t help, but it was a side story.

> That’s not the same thing as redundancy

It is. Redundancy doesn't necessitate the redundant option being identical to the first.

> ”Redundancy doesn't necessitate the redundant option being identical to the first.“

Yes. In fact, in a redundant system, using different designs or technology is often an advantage, so that a failure mode that affects one system is unlikely to affect the other.

But if something is redundant, it is “able to be omitted without loss of function”. Front and back brakes on a bike are not there for redundancy. They are components of the same braking system: without both in service, they don't work as well.

Or to put it another way, the front brake isn’t there as a spare in case the back brake fails. It’s there because without brakes on both wheels, you can’t stop quickly in an emergency.

> Front and back brakes on a bike are not there for redundancy. They are components of the same braking system: without both in service, they don't work as well.

Bikes are very different from cars due to the short wheelbase vs high center of gravity.

At moderate or fast speeds maxim deceleration occurs when the front tire applies enough force to lift the rear tires off the pavement thus removing the impact of the rear tires. Below maximum acceleration you could use the rear break but it doesn't do anything applying the front break slightly harder would do.

At sufficiently low speeds the rear tire can help, but it's really there for redundancy as even acting alone it doesn't work very well.

This only applies in ideal conditions (eg: dry tarmac). Where there is less surface friction (wet or icy surface, dirt or gravel trails, etc) you're going to quickly hit the limits of the tire's traction, so will need both brakes if you want to stop in the shortest possible distance.

Wet roads, cold ice, and dirt still provide enough friction to send you over your handlebars at speed. They just increase the maximum speed rear tires provide any benefit. Near its melding point ice isn’t going to provide enough friction for rear breaks to matter.

So sure there’s a minimal benefit in some very specific conditions, but no they are there for redundancy.

In reality, the rear brake contributes nothing (apart from redundancy in case of front brake failure) to being able to stop quickly in an emergency. The quickest stop is achieved by using the front brake as strongly as possible while bracing oneself to avoid going over the bars, which if done correctly, will mean the rear wheel will have next to no contact with the ground. That means locking the rear wheel with the rear brake will contribute nothing to stopping.

On pavement, when the front brake performs well and is operated near optimal power, the back tire will not have traction. The back brake is entirely redundant in that case.

> That’s not the same thing as redundancy

The law literally says mechanically redundant, as in failure of one cannot affect the other.

It's illegal to have a single hydraulic system controlling both.

Seriously, in England there are a lot more bicycles than ships (not to mention the differences in training and experience).

> What is the cost of fixing this bridge and + lost lifetime earning of all the people who dies + compensation to their families? Is that really cheaper than installing batteries plus electric motor?

I don't mean to contribute to this already-too-charged discussion any more than to say that the answer to this question is not as obvious as you think it is. If anything, I would bet that the former is less expensive than the latter, and I say that with immense sadness. Does that make sense?

And this bridge being down will shutdown the port and reroute all automobile traffic that used to travel across it for months and the bridge itself will require design rebuilding, all of which will be extremely costly economically.

Biden has said that the Federal government will pay to rebuild the bridge, in order to get it done quickly.

But presumably they will ultimately seek reimbursement from the Dali’s insurers. As will the Port of Baltimore and anyone else who has suffered damages.

at this rate it won't be hard to knock out several more major ports by the end of the year.

What rate? 1 a decade? Or longer? When was the last time this happened?

Conspiracy... some adversary is waiting for opportunities during unfavorable/aberrant conditions and triggering simple failures at impossibly inopportune times. Without any redundancy, conditions it looks like a freak accident. It would be interesting if you could come up with a likelihood for each conditions to have overlapped temporally. If someone comes to the conclusion that its possible to create the triggered failures it would be prudent to forbid sailing in conditions that might lead to these supposed "fly under the radar attacks".

> Maybe there's some lighter weight interventions we could do that would further halve the risk of something like this happening that are less costly than fully redundant engine and drive.

Redundancy doesn't inherently have to cost a lot more. For example, if you have three engines driving three props, they can each be 1/3 as large, and not necessarily weigh much more if at all. But then if you lose one, you lose 1/3 power rather than experiencing total loss of control.

> Redundancy doesn't inherently have to cost a lot more. For example, if you have three engines driving three props, they can each be 1/3 as large, and not necessarily weigh much more if at all.

Yah, from aviation everyone moved to twins because tri-jets and four engine jets were too expensive in comparison. Things don't scale up or down perfectly; in practice you end up with more maintenance.

But it seems like here they lost steering, so maybe there's something better we can do to keep steering more of the time (the cutover to emergency steering gear isn't instantaneous or perfect).

but two engine jets can fly on one engine for a while, however a one engine boat this big is an uncontrolled juggernaut when it has some speed and no engine because it doesn't have any redundancy.

Sure, I'm not saying what the ideal trade-off is. I'm just saying:

- The current accident rate due to lack of redundancy isn't too awful.

- Adding redundancy increases cost, even when it seems like you have the same total power or whatever.

My bias is towards a bit more redundancy than we have now, but not massive changes.

> but two engine jets can fly on one engine for a while

Not just for a while. They must be able to do so indefinitely, until you run out of fuel. Of course, you are going to want to get it back on the ground long before that happens.

Planes use two engines because they can land with one and smaller jet engines are about as complicated as larger ones. Ships have different constraints. For example, a lower output diesel engine could have fewer cylinders and correspondingly lower maintenance costs.

>> worm gear at the top of the shaft with a winch handle big enough to put a gang of men on it

They showed us one such station, on the USS Hornet in Alameda, it it in the officers' dining room.

Wouldn't a ship like this have bow thrusters? Seems like otherwise it would be impossible to get into port without a tug.

My understanding is that they simply use a tug when they're maneuvering by the dock. That's what a lot of tugs do all day.

Bow thrusters are only effective at very low speeds due to the Coandǎ effect

Thanks for the link to that book. I don't know if it's the because of this catastrophe, but it looks to be unobtanium at the moment. Will have to find it in the library.

> lack of redundancy

This is what I am surprised at from many angles. It seems to me that the ship, the port (in the form of lack of tugboats), and the bridge (in the form of lack of secondary protection of the pillars) all had a lack of redundancy and secondary options.

The author GPLed it and put it on the internet at one point: http://martrans.org/documents/2006/safety/The%20_tankership_...

Oh, nice. Thanks for the heads up there and again for the book reference.

See https://news.ycombinator.com/item?id=39836079

Yeah that's not very typical, I'd like to make that point. These ships are built to very rigorous maritime engineering standards.

No cardboard is allowed in the construction.

We had a 100-200 car ferry here in Seattle lose power and run into an island last year.

I think it was something like bad fuel killing the generator.

Probably not the case here, but one possibility could be land-based remote hacking. [1]

[1] - https://warontherocks.com/2021/10/cant-sail-away-from-cyber-... (2021)

I was curious about power outages as well, and why tugboats aren't required for all container ships that navigate under bridges. I'm not arguing that tugboats MUST be mandated; just wondering about the cost/benefit analysis. This claims that power outages are more common now (but doesn't cite sources/stats) in areas (specifically California) where diesel fuel is required, rather than bunker fuel: https://baykeeper.org/news/column/tugs-test-towing-giant-shi... It also makes it clear that relying on tugboats to be on standby and "swoop in to the rescue" is seriously wishful thinking where bridge safety is concerned. This article from 2019 is about a power failure due to an Oil Mist Detector that didn't have a "harbour mode" option of keeping the engine running at reduced RPM so you can still maneuver. It also shows the link between engine failure and a need for tugboats under "lessons learned": "– Although it is tempting to free harbour tugs as quickly as possible, in the restricted waters of a small port their assistance can be invaluable should something go wrong." On the other hand, what safety or economic issues do tugboats cause? It will probably become a topic of discussion or investigation at least.

The American courts should hit Maersk really really hard financially and get them to foot the bill for all losses of the bridge collapse. Shipping companies should not be driving vessels of these huge tonnages with such poor levels of redundancy and poor levels of manning.

It is insane for a 100,000 tonne vessel, that takes so long to stop due to its incredible inertia, that can find itself many thousands of miles from land, to rely on one engine, one gearbox, one shaft and one rudder; without sufficient secondary and tertiary back-up systems. Why was there no battery back-up, or motor on the shaft? Surely the bow thrusters should have a battery back-up to stop such a lurch to starboard.

How can all of the generation and all electrical busbars fail at once? Even if the fuel was bad, surely the generators should draw on separate fuel tanks. For such a large and relatively modern ship to suffer a total power failure is complete corporate incompetence.

If, as some allege, the refrigeration containers were causing problems, and total power outages occurring before sailing, the vessel should not have sailed, certainly at night. If this is the case, The Master needs locking up. But, poor man has to take the blame, because he is cheaper than a Danish Master and his Singaporean employer (if he is employed and not a contractor) also operating in a cheaper flag state than Denmark. The Singaporean Company also needs hitting hard if the culture was the cause of the Captain sailing after such alleged pre-sailing power outages.

Maersk outsource to reduce personnel and running costs. They use the cheapest crews, cheapest ships and need hitting very very very hard. We might then stop this culture of wealthy shipping companies using every method possible to avoid complying with IMO and more rigorous Nation State standards, operating in the shadows and ducking accountability and responsibility.

The video is surreal, it looks like it barely bumps the bridge and 2 seconds later the entire thing is gone. I don't know what I was expecting, the bridge just looked extremely fragile, makes me wonder what other bridges are at risk of an event like this.

It's somewhat counterintuitive how much energy can be in something moving so slowly. I say somewhat, because when you're up close it's much more obvious, but you're right that on a video it doesn't look like much.

The same go for cars. I was hit by a car which was already slowing down but over ran the line and hit me. The car couldn't have been going more than 10 mph but it was enough force to fracture my knee (the fracture type is also colloquially known as a bumper fracture).

> It's somewhat counterintuitive how much energy can be in something moving so slowly.

Reminder: Kinetic Energy = ½mv^2

Squaring numbers can make them big in a hurry.

But in this case with slow speed, it's the massive (literally) amount of mass of the cargo ship that gives it an un-intuitively large amount of energy.

8kn isn't super slow

It's 10 mph which is pretty slow as speeds go.

Slow-but-irresistible force meets movable object.

All objects are surprisingly movable when they encounter enough mass.

To your point, it is mass. Most people don't understand mass on water. At 1 knot the ship would do the exact same damage, topple the support and drop the bridge.

Motor control and rudder control in a momentumous frame of reference.

sqrt of 100K times weight of a car is 300 cars worth.

Nitpick: squaring makes numbers greater than 1 bigger, and numbers smaller than 1 smaller. In this case we're squaring something with units, and we can't say the input is greater or smaller than the output, because they have different units. What we can say, is that v^2 curves upward: it grows faster with increasing v, and slower with decreasing v.

This disconnect happens with boats quite a lot. For example, I can, by myself, pull a 45 foot grand banks trawler in shallow water. I know because I've done so.

But at even very low speeds, I cannot stop it from hitting a pier. I have not tried to do this, but every harbor master has a bunch of stories about people trying to do so and getting a leg or an arm or something squished and pulverized.

People who are not boat people rarely recognize these sorts of dangers, which is why so many get hurt on boats. "I can push us off the dock, so I can definitely keep us from hitting it." Nope, Sir Isaac Newton says you're wrong.

To anyone reading this who isn't an experienced boater:

If you are invited onto someone else's boat, sit down and shut up during docking, don't talk to friends, let the captain concentrate. Don't help, if the captain wants you to do something, they will let you know. If you think you know better than the captain, and this advice is unknown to you, you don't know better. Being a good guest during docking shows experience and helps get an invite back.

This advice also translates for general aviation during takeoff, landing and taxiing.

This is great advice. For myself, docking in windy situations can be nerve racking. The old adage is to only dock as fast as your willing to hit the pier, and for me this means slow as hell.

I always let guests know exactly what I want them to do, and to your point, it's mainly to sit tight and let me focus.

Wind, current, tides, your own boat at risk as well as other people's boats alongside... docking can certainly get the heart pumping.

(Liveaboard cruiser here)

Screwing around during docking is a great way to get to swim to shore at an unspecified later date.

Similar to stay quiet if the car is about to merge into traffic. But with a boat the stakes are 100,000 times greater due to the huge momentum and that it would be gliding and not slowing down like a wheeled vehicle on land.

Take things slow so you aren’t the show.

I have a 44ft sailboat. Docking is not easy. People do not realize how difficult it can be

Given how hard I find docking my 16-foot bowrider if there’s more than a light breeze, I can only imagine.

Try docking a sailboat on a river. Then slow isn’t an option, since the current will sweep you away in a heartbeat. The key here is planning ahead, including a plan for what to do when you don’t get it right. And you won’t, on the first couple of attempts. I’ve seen it in action, totally hair raising to watch.

This is one of those situations where I know I will not be good enough often enough, I will totally warp in. River currents are hard.

This hit me a a bit ago - you can't really tell how big ships are if you just see pictures of them on sea. I recently hit this in real life. Yeah it's a ship. Oh. It's like 3 - 4 times as tall as I am above water. And it goes 2-3 stories down. And holy hell, a crows nest 30 meters up is... really high up?

And we got the good tour, because we had a severe storm warning as we visited that ship - the kinda storm in which gusts stop you in your tracks and forces you to lean into it to not fall over. Was a great experience. I wouldn't want to be up there with that kinda wind.

And this was a medium sized clipper, somewhat on the small size.

And based off of that, I kind of want to see a retired battleship or an aircraft carrier. Because now I have an idea of how dumbfounded I'll be at those kinda dimensions. It just doesn't appear that big on photos!

The best place I've seen huge ships is Hamburg. People sit and picnic on beaches along the river in the summer, and enormous container and car carrier ships go past.

Yeah, this was the Rickmer Rickmers[1] in fact.

We had a team we work with a lot over here in HH and went on the treasure hunt on the Rickmer Rickmers as an event. That was very nice - they spread a bunch of little puzzle boxes across the ship so you can search for these, walk through the museum and look at stuff. And the puzzles were neat as well - you'd use the compass the actual helmsman used back in the day to figure out where east is to find some clue, count pests in cargo and such. Very recommendable and a lot of fun.

We just didn't climb up the ropes in winds that almost pushed you over on foot, haha.

1: https://www.rickmer-rickmers.de/

Landlubbers are accustomed to momentum (p = mv) behaving in a certain way instinctively from years of experience, where the heavier something is, the more frictional force against it from the ground, and therefore the mass behaves a certain way. This breaks down once the expected friction changes a lot, e.g. trying to stop a moving car or, like you said, a boat in water. I'd imagine it's the same thing in space, where a slowly-moving but massive object would surprise someone at their inability to stop it.

Force = mass * acceleration, it might be slow but how much does a container shop weighs? 100, 200 thousand tons?

That ship had a 10,000 TEU capacity and was actually hauling a little under 5,000 TEUs. An empty container weighs a little over 5,000lbs, and a full one can be up to 67,000lbs.

If you do the math, you find that it’s just an astronomical amount of momentum, and there’s no effective defense for a bridge that needs support in more than 30 or so feet of water.

Throwback to the scene in The Day After Tomorrow where the cargo ship comes to an almost instant halt after impacting a bus wreck under water. For some reason it managed to stand out as ridiculous even in that movie.

Somebody should do a side-by-side of that scene with this threads scene in gif.

Speed 2: Cruise Control on the other hand: https://www.youtube.com/watch?v=gBxaGB65TB8

I just saw in a YouTube video yesterday that they actually built a full-size model of the ship (or at least the bow area) and the bit of town it hit. The director didn’t want to use CGI or miniatures.

He spent a full quarter of the movie’s budget on that one scene.

Corridor Crew SFX specialists watching/explaining the stunt:

https://youtu.be/_lDM1nAmPHI?t=797

The bow is real, the back of the ship is CGI.

> there’s no effective defense for a bridge that needs support in more than 30 or so feet of water

You deflect it. Failing at that, you direct the force into destroying the ship.

Of course, the best solution is no in-water pylons. But that isn’t always feasible.

> direct the force into destroying the ship

Nice immovable object you've got there.

You put it ahead of the pylon so that even when the dolphin or bollard is destroyed, it redirects the ship to—at worst—a glancing blow with the pylon.

You don’t need to dissipate every joule of kinetic energy in the vessel. You just need to redirect it away from the pylon. That horizontal component can be done with bollards and dolphins sufficiently that even a relatively direct original angle should only damage the fenders. From what I see, there were zero such protections around this bridge.

Nothing can protect against a direct hit. But most hits aren’t direct, and those can be redirected without catastrophic pylon failure.

> direct the force into destroying the ship

> You put it ahead of the pylon so that even when the dolphin or bollard is destroyed

Dude, seriously? That has nothing to do with what I was replying to.

Thank FN gosh that those TEUs were likely ~mostly empty returns.

If thems be full, that guy would be illegally parked for far longer.

What is the traffick-routing-around plan look like? (both sea and land, helicopters cry in lack of TEU)

Jeasus - seriously - if that was an inbound shipment then it would be worse - this appears to have been leaving - which would infer that the TEUs were more empty than full.

do they ever run these empty?

I would expect they're as close to full as they can get in every trip. They'd be terribly inefficient ways to transport goods otherwise.

With what would they be filled with?

Ideally, something exportable from this region.

Some import products are crazy cheap because cross-planet shipping is basically free because it's the reverse end of a trip carrying valuable stuff. But they mainly applies to ships returning from low development level regions.

Like what? What does na export in containers?

Most our exports are bulk not container afaik

While the majority is bulk, the US does export a lot of industrial machinery. It's just not stuff you normally think about - like the large hvac systems on the roof of large buildings or the caterpillar earth moving equipment/parts to make roads.

North America has lots of land and oil. Timber (Canada), plastics, and corn fertilised by nitrates that were made using fossil fuel energy. Corn probably doesn’t ship in containers but corn-fed beef and poultry do?

Apparently, I was wrong - they are reporting it as a "fully loaded" -- but that does not mean the TEUs were full of goods and services... but thats what they are calling it. So I have no Idea.

Unless ImportYtei.com can get the bills of lading for that ship....

there’s no effective defense for a bridge that needs support in more than 30 or so feet of water

You put in sheet piling 50 meters upstream, and you fill the box with rocks. That's state of the art practice, nowadays, but that bridge was 50 years old.

The sheet piling didn't need to be 50 years old.

In 1977 (and in 1972, when construction began), vessels of this size did not exist, and certainly were not allowed in the harbor[1]. But over time, they were given authorization, despite the fact that they could collapse the unprotected bridge like a load of toothpicks.

The real crime here is that there was no retrofit to protect the pylons. It was almost certainly considered and rejected due to cost.

[1]: https://logisticselearning.com/wp-content/uploads/2022/06/Co...

The ship in question here was 10K TEU.

The Oil Tankers of the 70s were the largest vessels ever built. Today the largest container vessels are starting to creep up to their size, but not weight.

The container vessel in question is tiny compared to e.g. the Seawise giant or Batillus Class.

https://en.wikipedia.org/wiki/Seawise_Giant

https://en.wikipedia.org/wiki/Batillus-class_supertanker

Those ships would never have been permitted in the Baltimore harbor. They presumably still aren't, since there's no reason for them to be there.

It only depends on where the large-scale refineries are. If Baltimore had one they would be going there.

The smaller VLCCs are dime a dozen and they are 2-3x the weight of the Dali.

The Port of Baltimore does not even have an oil handling facility, never mind the fact it could not admit a VLCC even if it had cause to.

Even ports on the US Gulf Coast do not generally have the capability to dock VLCCs.

https://www.eia.gov/todayinenergy/detail.php?id=36232

If Baltimore had been anticipating VLCC traffic in the 70s, then presumably the bridge would have been built accordingly and this incident would not have led to a collapse.

According to the marine traffic track shown in the YouTube analysis above, the ship looks to have been heading through the channel, but then nosed in right under the bridge. Would have sailed right past upstream dolphins, and rammed the pylon from the inside anyway.

I think the only reasonable goal would be to design the bridge to minimize damage to it, so that one damaged section doesn't bring down others.

Building a bridge to actually stop the ship is not only infeasible, but it would likely kill (more) people onboard.

the modern practice is layers of defense; in addition to building a bridge that doesn't fail at a single point of failure, you also generally design what's around a bridge pier to stop or at least slow down the ship (by, say, running aground onto a bed of rocks around a pier)

For a bridge such defenses are called dolphins.

"A notable example of dolphins used to protect a bridge is the Sunshine Skyway Bridge across the mouth of Tampa Bay. In 1980, the MV Summit Venture hit a pier on one of the bridge's two, two-lane spans causing a 1,200-foot (370 m) section of the bridge to fall into the water, resulting in 35 deaths. When a replacement span was designed, a top priority was to prevent ships from colliding with the new bridge..."

Source: https://en.wikipedia.org/wiki/Dolphin_(structure)

The MV Summit Venture was a 33,900 deadweight tonnage ship. MV Dali was a gross tonnage of 95,128. Nearly 3× as large. It's questionable whether dolphins would have totally prevented such a tragedy.

Yet similarly, expect dolphins to be brought up as a key component of resiliency for any designed replacement bridge.

That's also a thing.

But note how the main bridge piers are on giant islands much larger than the pier itself: https://en.wikipedia.org/wiki/Dolphin_(structure)#/media/Fil...

If you really want to make it unblockable you build a bridge+tunnel. https://en.wikipedia.org/wiki/Bridge%E2%80%93tunnel

The CBBT is downstream of the bridge which collapsed. I've driven it many times.

https://en.wikipedia.org/wiki/Chesapeake_Bay_Bridge–Tunnel

It has tunnels because the Navy did not want the bay blocked if the bridge dropped into the water. Which is exactly what has happened in Baltimore.

It's not the impact, it's the fact that it just keeps pushing. Movies commonly use slow motion and time extension via editing for destruction scenes because (as we've just seen) real time doesn't always look impressive to the untrained eye.

Also, there's a lot of mass concentrated in that ship. It's the equivalent of hitting a window with a sledgehammer. Small recreational vessels could probably crash into those pylons all day long.

Indeed, the whole bridge failed because the impact didn't exceed the impact strength of the bridge's material, which means the whole bridge bent until the deflection exceeded the tensile strength of the material. A missile impact with the same total energy would exceed impact strength and would probably have destroyed only part of the bridge.

Did the math, this seems surprisingly spot on, at least from the energy perspective. 100k tons going 7.5 kts is about 160kg tnt equivalent which is a little less than the explosive power of a Mk83/GBU-32, probably not enough to take down an entire bridge, just one span if you're lucky. That said, the issue is the bomb expends most of its energy moving air around, the freighter expended nearly 100% of its energy on the bridge.

Thank you for breaking it down like this. As someone without an engineering background, your explanation (along with some Googling for terms and definitions) really helped me grasp what happened.

You got me wondering:

> the whole bridge failed because the impact didn't exceed the impact strength of the bridge's material

When I first read this, it initially threw me off. The cargo ship's impact not exceeding the strength of the bridge sounds like a positive thing, but upon closer reading of your comment, it sounds as if it was the catalyst to the entire bridge collapsing.

So, how do engineers balance these properties of impact strength and tensile strength, especially considering large ships channel through these bridges near their pylons frequently? How much engineering goes into the possibility of large structures hitting their pylons?

> The cargo ship's impact not exceeding the strength of the bridge sounds like a positive thing, but upon closer reading of your comment, it sounds as if it was the catalyst to the entire bridge collapsing.

I had intended to add that exceeding the impact strength typically results in a local failure near the impact point. A tensile strength failure could happen far from the load and so could be more catastrophic.

I'm not sure if it would have made a difference in this case though, as destroying a main pillar by exceeding impact strength would have by itself transmitted most of the full bridge load to the remaining pillars and that alone may have been enough to exceed the safety margins on the tensile strength that are built into all structures. Unclear without more data, but there was a chance it could have survived in that case, but no chance with the ship consistently applying more and more shearing load.

> How much engineering goes into the possibility of large structures hitting their pylons?

Good questions, I'm not familiar enough with it to provide any further insight, except to say that I believe this bridge was designed long before these huge container ships existed. If they factored ship collisions into the bridge's design constraints at the time, they've no doubt been dramatically exceeded with these huge ships.

I don't think impact strength is factored very much into static structures, tensile strength is more important. It only comes up in very unusual situations like this or 9/11.

Bridges were not designed for being hit. They were designed to span. If those designing and engineering it had considered an impact, the design would not be catastrophic but rather sectional. If sectional, each span would remain standing rather than collapse like dominoes. It takes 3 miles to stop a 100k ton stacked container ship. The things nobody has mentioned are: Current direction and speed. Wind direction and speed. The entry of the vessel in relation to the bridge. The fact that dragging anchor would have on the starboard side pulled the bow right into the pilon, the worst case.

There's also the loads are balanced on the pylon. When the collapse took out the bridge on one side of the pylon, the other side failed as well. You can see that in the video as the bridge on the right side of the pylon is no longer counterbalanced by the bridge on the left side, and collapses.

Imagine you're holding up a barbell with heavy weights at each end. If the weights on one end drop off, the bar will tilt strongly in the other direction, dropping the weights off on the other end.

> I don't know what I was expecting, the bridge just looked extremely fragile, makes me wonder what other bridges are at risk of an event like this.

The bridge style in question

> Conversely, continuous truss bridges rely on rigid truss connections throughout the structure for stability. Severing a continuous truss mid-span endangers the structure. However, continuous truss bridges do not experience the tipping forces that a cantilever bridge must resist because the main span of a continuous truss bridge is supported at both ends.

* https://en.wikipedia.org/wiki/Continuous_truss_bridge

* https://en.wikipedia.org/wiki/Francis_Scott_Key_Bridge_(Balt...

So taking out one end basically takes out the whole thing.

I would not be surprised that when they build the replacement, it will be a design where the individual components are more self-resilient, like:

* https://en.wikipedia.org/wiki/Cable-stayed_bridge

The engineering best practices, budgets, and needs may have been different fifty years ago. Cargo ships were also a lot smaller fifty years ago.

cable stays are also generally more popular these days because of the differences in material. All other things being equal, concrete is generally a lot cheaper than a steel truss bridge these days

If they play the cards very carefully, they can pull out and recycle all the steel of the old bridge, and use that to pay for a new (cheaper) concrete bridge.

When you play about with game engines long enough, you start to realise that momentum is the key metric to track rather than speed. Especially in water magnitude can be very deceiving but to give some quick math, this vessel had a momentum at impact of about 154,000,000kg⋅m/s. For a car to have equivalent momentum it'd have hit the bridge at 156,580 mph. Humans are just less adept at appreciating mass vs velocity.

Energy matters, too. That hypothetical car has the order of 1 kiloton of TNT of kinetic energy. The resulting blast would have been large.

(This is about the estimated yield of the Beirut explosion.)

I would rather get hit by a slow moving object than a fast one with equal momentum.

If you're moored on the ground you'd be torn apart in both cases

On the other hand, if I were hit by a loaded shopping cart at 3 mph and I weren’t allowed to move my feet, I’d probably be okay if I saw it coming.

Keep the same momentum but scale the mass down to, say, 200g. Now it’s supersonic, and it will hit with maybe 10x the energy of a musket ball. This would be extremely damaging and likely lethal.

(If you make the mass too small, it might go straight through a person, in which case not all of the energy is delivered.)

But the point was that if you were hit with a full container ship at 0.1 mph and not allowed to move you'd be dead.

The only reason why a high energy but slow moving object (thus high momentum) is harmless is that it will deliver a small acceleration to you and you won't suffer from the consequences of a high acceleration (which is what generally kills people when they hit something like the ground at high speeds). But that assumes that you're free to be accelerated and move away.

I think this is a bit too simple. People can get injured and objects destroyed in multiple ways. For example:

One could be torn apart. If you are glued to the ground and you are pushed away with too much force to resist, you have a problem. You can stretch or move a certain distance and withstand a certain force while doing so, and the product of those numbers is the energy you can remove from the thing hitting you. If the impactor is at a fixed speed, then you can turn that momentum into an energy, but that’s a bit silly. You really can stand still and deliver more stopping impulse to an object moving toward you when it’s moving slower because you can resist for a longer time.

One could collide with an effectively infinitely massive object. But the momentum of that object seems irrelevant — hitting a brick wall on wheels at 25 mph seems much worse than hitting the Earth at 0.1mph despite the Earth having many orders of magnitude more momentum. The impact velocity seems more relevant.

One could get hit by a fast-moving projectile. This is complicated, and neither momentum nor energy seem like sufficient measures. As an extreme example, ultra-high-energy cosmic rays surely hit people on a somewhat regular basis, and I’ve never heard of anyone noticing such an event, despite the energy involved being quite macroscopic.

Hm. I'm no physicist but I think your math is off. Remember it's velocity squared. Your car going that fast is has more than a kiloton of TNT or approaching 5 terajoules of energy... that can't be right.

For a 2 tonne car, my very rough math puts it at more like 2100 mph.

Momentum is just mv, not mv².

I can't edit my post now, but to be clear I was talking about kinetic energy. I would have thought momentum is not a very useful thing to talk about in a case like this where there was some pretty obvious transformation of energy into damage, etc.

As I said though, I'm far from a physicist so happy to be schooled if I'm way off...

Spot on.

Probably most of them. A structure like that not designed to bear vertical loads, not lateral ones, other than high winds.

The knee is like this too. It lets you stand, run and jump just fine, but you can knock down an opponent with a relatively mild lateral impact to the knee.

Much more of the bridge collapsed than you might think, though, far from the impact.

Bridges are design to withstand a very predictable type and direction of force. It can withstand the lateral wind, but imagine how much force a fully loaded cargo ship can put into it. Once one segment gone the rest is history, because makes the who construction imbalanced.

F = MA

A looks like 'barely a bump' M is what got the bridge.

I remember when I was a kid, I left a bus, and the bus started moving, and I, not being intimidated by the bus moving very slowly (somewhere between 5 and 10 km/h), didn't move a safe distance away from the bus. I think the bus, due to the nature of its maneuverability, had its tail moving not in parallel to me but slightly towards me - so when it has "touched" (hit?) me, even though I thought it was just sliding in parallel, the force was so strong I made a full 360° turn - and I was a tall and chubby boy.

I ended up with no injury, not even a bruise as far as I can remember (who would count bruises as a kid), but definitely with an intuition to respect mass.

> I don't know what I was expecting, the bridge just looked extremely fragile

The strongest man in the world probably seems pretty solid. Put him at the bottom of a 3 degree grade and release the brakes on a full tractor trailer and he'll seem fragile too.

Apparently (this is just via someone on Reddit who supposedly heard/read it somewhere) the ship mayday'd on losing power hoping the bridge could be cleared.

But why not (or did it?) also just blast its horn repeatedly, drawing attention so people on or near the bridge would notice it and realise something was wrong and perhaps even where it was headed?

I'm sure it's not allowed generally and not the protocol and whatever ... But it does seem like a common sense & do whatever you can sort of situation to me?

Why would a driver think a ship's horn was signaling them?

AIUI most souls on the bridge were construction workers filling potholes, not drivers. But either way I'd have thought a certain amount of horn blowing would catch my attention just for being out of the ordinary, even though it's also not ordinary for ships to (need to) signal me.

Ya the people on the bridge would have less than 4 minutes to figure out the ship is crashing then to clear 2500 feet of bridge. When you're working with construction equipment you'd probably not notice till you had seconds left.

4 minutes is a lot longer to save your life than nothing? And do you really think that's the answer, that was the calculation on the ship - well they only have 4 minutes until we hit anyway, so there's nothing they can do, not worth it?

I wasn't criticising anyone, I was 1) asking if that happened; 2) asking why it might not have.

I think the answer is much more likely that the loss of power disabled the horn (as others have suggested) than that the crew thought it wasn't worthwhile because there was insufficient time for anyone on the bridge to fare any better anyway!

So, it turns out they did call in an emergency and the police did shutdown the bridge. The police had no direct way of reaching the workers and weren't going to wander out there with an imminent impact. So, evidently, no there was not enough time.

'So,' I said that in my initial comment. The police may not have had a way to reach them, but the horn would have. There was a lot more time than none, who's to say if it would have helped. I think the correct answer is as given by others, that actually the loss of power would have disabled the horn too.

> But why not (or did it?) also just blast its horn repeatedly,

Hard to blow your electrically driven horn when you've lost power.

I suppose I assumed it was compressed air, that once you had a 'full' (at pressure) tank, you could do a certain amount of blowing even without power. But fair point, I don't really know how they work, and if they are actively electric I certainly didn't know that and obviously that wouldn't have worked and so there's the answer.

> I assumed it was compressed air, that once you had a 'full' (at pressure) tank

Even so, it probably still requires electricity to activate the solenoids to open the valves or whatever. I'm speculating since I don't know how large boat horns work, but I wouldn't be surprised if they require power.

Oh good point.

Blasting the horn repeatedly is not a standard signal, but there are standard signals which might apply to a situation like this, for example "vessel not under command", "collision imminent", "vessel reversing", etc.

Don't expect car drivers on the bridge to understand ship signals, though.

Also, how does the driver know what to do? Stopping on the bridge, even well before the point where the ship hit, was clearly the wrong choice. Authorities need to stop new cars from entering the bridge while those on it leave, but that takes more than a handful of seconds to arrange. Unless there are traffic lights, perhaps.

Yes, there's no reason for a ship to attempt to signal drivers on a bridge, nor is there any way for them to do so. Signals are for communicating to other ships.

Because horn blasts are very specifically meant to communicate something to other ships. Once you're in "just blast it" mode you're seconds from disaster. I recognize the nobility of your suggestion, but I don't think it could have saved more than couple lives at most, probably none.

Well yeah, they were only minutes away at the point they lost power, there was very little time to do anything at all, that's why I asked. Personally I can't really imagine anyone holding it against them for using the 'signal that's for other ships' 'incorrectly' or 'against protocol' in such a situation. I think the comments speculating that the horn is either purely or in some way (e.g. solenoid) dependent on electricity is more likely the answer. I think a reasonable human in that situation who knows what's going on (that's why I mentioned that they apparently were able to radio/however they mayday that there's an issue) is going to do whatever they can, including use the horn wrong.

There is a proper signal. You are supposed to give at least five short signals if you think there is an impeding collision.

Alright well feel free to read my original question as if I knew and meant that then, I don't think I precluded it.

> But why not (or did it?) also just blast its horn repeatedly,

It's hard for people on the bridge to understand what that means. The more it blasts the horn, the more likely people to turn around, stop and maybe get their phones out to take a video what strange thing this ship is doing. By the time they realize the impact is imminent, it's too late, unless they take a helicopter ride.

There are specific horn signals (one prolonged, or seven-short-one-prolonged, are what I'd guess would be appropriate here), and COLREGS do explicitly say that you can use whatever you need to get attention in an emergency as long as it's not confusable with some official signal. But as other commenters have noted it wouldn't have been specific enough to get the workers etc to clear the bridge before the impact.

That timeline implies that there was only four minutes to respond. Is that correct? Where was the ship going? Does it travel under this bridge on its own power rather than a tug boat?

What I am wondering is: why couldn't the bridge have been blocked off preventing casualties? It seems like more than just the boat and operators' failing if there's no time or secondary precautions if such failures occur.

I wonder if it makes sense to protect bridges with pylons like they have in front of buildings to stop cars and trucks.

It was blocked off the shortly after the ship pilots sent their mayday signal and declared an emergency, giving the traffic that was on the bridge time to make it through.

Most (all?) of the people on the bridge were contractors repairing potholes.

> I wonder if it makes sense to protect bridges with pylons like they have in front of buildings to stop cars and trucks.

They're called "dolphins" and some bridges do have them.

> It was blocked off the shortly after the ship pilots sent their mayday signal and declared an emergency, giving the traffic that was on the bridge time to make it through.

This video makes that a little hard to believe: https://www.youtube.com/watch?v=qJNRRdha1Xk. Looks like traffic was crossing up until the last second.

Will have to do some more reading as it's very confusing what the ship was doing and what it should have been doing under normal circumstances. In the video, it almost looks like it was steered directly into the bridge. Very confusing.

> They're called "dolphins" and some bridges do have them.

Thanks for that!

yea if you watch the longer video they stopped traffic only a few seconds before the impact. incredibly lucky.

Relevant discussion on whether Titanic also tried to do a full reverse and, if true, if this was the right decision: https://www.reddit.com/r/titanic/comments/1abvwqt/if_the_tit...

Current personal suspicion after watching your linked video (excellent discussion by the wgowshipping author) is:

Catastrophic engine failure (1:24) causing wide scale power loss.

No rudder control, rudder drift, and ship alignment drift (1:24-1:25:30)

Power restored and ship reengages prop with bad ship/ruddder alignment (1:25). However, ship is now pushing itself into a further bad turn. Pilot likely stomps the brakes realizing misalignment. Obviously 2-3 minutes is not enough to stop 100,000 tons at 8.5 kts, since it only got to 7.5 kts before crashing. Power loss may have caused total rudder loss.

Similar to a car that hits ice, wheels have arbitrary alignment when they reengage road, when power starts being delivered again, car swerves towards concrete barrier even with brakes. Driver with limited crash experience is mostly just panicking and stomping.

How many pilots, trained or not, really have any experience with a 100,000 ton ship in a crash situation with responses where seconds matter?

Edit: Also, economic disaster for Baltimore.

> (Wiki) The Port of Baltimore generates $3 billion in annual wages and salary, as well as supporting 14,630 direct jobs and 108,000 jobs connected to port work. In 2014, the port generated more than $300 million in taxes. 1st in automobiles, light trucks, farm and construction machinery, imported forest products, aluminum, and sugar. 2nd in coal exports.

Edit2: Bloomberg has an economic look including info on autos. ~$500 million in March 2024 so far. Honda, Mercedes, Subaru likely worst hit. https://pbs.twimg.com/media/GJmvXiCWkAAgDcE?format=png&name=...

3,600 commercial trucks / day. Hazardous material transport has a 30 mile detour. Baltimore had $350 million of insurance. However, Brent Spence Bridge is noted for cost comparison at $3.6 billion and 1/5 the length.

Baltimore StreamTime also has live view with ongoing discussion. https://www.youtube.com/watch?v=83a7h3kkgPg

Panama Canal pilots.

I'm not sure what configuration of props a ship like this has, but in my experience with a 40ft sailboat with a single propeller you have absolutely no rudder authority while reversing. I've read that some large ships also are direct drive--there's no transmission between the engine and the propeller, so "reversing" (if it's even possible) entails shutting down the engine and restarting it in reverse. This can be done with a two stroke engine. And yes, 8.5kt is not slow when you're displacing 100k tons, no correction will happen quickly.

This reminded me of an old physics book I read where author claimed that Titanic also lost rudder control and yawed because of full reverse.

Titanic was a “triple screw steamer,” meaning it had three propellers - port, center and starboard. The port and starboard propellers were capable of being reversed, while the center propeller could only propel forward. You can see this in the 1997 movie as they show the props when they throw the ship into reverse.

The center prop (that only goes forward) is the one directly behind the rudder, so the theory is partly that they lost some steering advantage when they lost the center prop.

No variable-pitch propeller?

> in my experience with a 40ft sailboat with a single propeller you have absolutely no rudder authority while reversing.

In general it depends on the rudders and the boat.

Longer keeled boats don't respond well in reverse at all but more modern boats (like mine, 1990) will do better but will still need some way to have steerage. I can certainly manouver around the marina in reverse, it's just harder than forwards and I need to be going a bit faster to get the control.

Long keeled boats don't respond well going forward either, right? Compared to flater boats with a modern keel.

All I really know about long keels is from what people have said. They tend to track well and don't tend to make as much leeway, but perhaps at the expense of speed due to the wetted area, and they are hard to steer backwards. Not being particularly manouverable forwards isn't really an issue if you're spending several hours going mostly in a straight line.

Modern flat boats (like the 2017 Dufour I learned on) are highly manouverable at slow speed, we practiced spinning the boat on the spot by using prop wash over the rudder forwards then ticking over in reverse. Could turn the boat in not much more space than the boat length, but may not track as well, may slam more, and make more leeway.

Going backwards in the marina I often steer on the engine rather than the rudder (though I keep the rudder aligned with the engine of course). Obviously that's in a tiny sailing boat with an external engine, but I thought large ships also often have a steerable front propeller to assist with steering and mooring. Although maybe these very large ships use tugboats for that.

an outboard? that is very very different because you control the direction of thrust also.

My boat has an inboard diesel so no ability to direct the prop. It does have a bow thruster, but it's only really used at slow speed, usually right at the point of docking and undocking in tight spaces, once you get the boat moving in forward or reverse you don't need it.

I have no idea about container ship sized boats, though I'd imagine a bow thruster of steerable prop might not be practical at that scale.

Well if you keep rudder aligned with the engine (i.e. parallel) you are really using both, not just the engine.

> my experience with a 40ft sailboat with a single propeller you have absolutely no rudder authority while reversing.

I have to protest here. Reversing and using the rudder on a 40ft boat works perfectly fine. I've done it on multiple sailing boats. You need to hold tight so that the rudder wont slap you if using a stick.

If you have enough way on to combat the prop walk, yes. But in a situation like backing down trying to come to a stop (at least in my boat, a 1962 Block Island 40) there's a very long "dead time" while transitioning from slowly moving forward to slowly moving in reverse where the rudder just doesn't do anything. The way I maneuver in these situations is to do all my heading corrections in forward gear, where prop wash over the rudder gives it authority. So it's a game of shots of reverse, corrections, rinse, repeat.

EDIT: also planning ahead is important, because if I do it right the prop walk in reverse can be used advantageously.

Also, with the BI-40's barn door rudder it'll slap you through the wheel if you're not careful. Almost broke my leg that way, not a lesson to forget.

Nice boat! Ye it does not look too nimble in harbours. Somewhere over 40ft with "light" boats is where I feel you get into the "you got one chance" harbour manouvers (unless there is some front sideways motor cheating).

It happens something that I really can't explain, but I guess it is weight related. Or maybe area. Dunno.

Yeah it's right around 20000lb displacement, so momentum is a real thing ;). The fiberglass is over 2" thick at the keel tapering to a mere 1" at the hull to deck joint. Decks are solid glass as well. At the time it was a newfangled material and they were scared of it so they used a lot.

Also, the bow seems to catch the wind really hard so you can get spun around if it's blowing and you head off the wind too much without enough way on. Leave room, plan ahead, have a backup plan, etc.

Isn’t there a pretty big difference in how much rudder authority you get between just making way astern, and having the engine in full reverse while still traveling forwards at seven knots?

It's complicated.

The rudder is a wing, it's just vertically oriented and underwater.

The rudder is capable of stalling, just like any wing. The rudder only produces lift related to the flow of water over the rudder. The lift produced by the rudder is what is experienced as turning force. The tiller or wheel changes the angle of attack.

I used to helm a racing sailboat with a high aspect (long & narrow) rudder. It could provide a lot of turning force but stalled easily. It didn't work as well under power as it did under sail; I suspect this was due to the turbulent flow off of the propeller, which was forward of the rudder.

On the Dali, the rudder should have been providing some turning force due to the 7+ knot flow of water over the rudder. Full reverse propeller might have impacted that; I can't comment because I've never helmed a ship that large.

Additionally, a single-propeller vessel like the Dali, will have "prop walk" - asymmetric thrust that pushes the stern of the craft one way or the other while the propeller is rotating.

I'm only a minimally experienced (coastal cruising) sailor so there's plenty of things I don't know, but this is the first time I've heard the rudder as a wing (lifting surface) rather than as a neutral control surface.

It sort of makes high-level sense that a lifting bias could in theory work as a counteraction to propwalk. But the terminology is a bit confusing because aerodynamic lift is a byproduct of air being a compressible medium, whereas water is not. Maybe lift means something different when we're talking about water?

At any rate in scenarios where the prop is not engaged, which in a sailboat is most of them, I don't think I've ever noticed a tendency for heading to track predominantly one way or the other, in circumstances where it seems that would be very pronounced and hard to miss, like extended running downwind. Is the lifting body rudder mainly a performance boat thing? Or perhaps am I just so used to trimming this bias out that I don't recognize where it's coming from?

> But the terminology is a bit confusing because aerodynamic lift is a byproduct of air being a compressible medium, whereas water is not. Maybe lift means something different when we're talking about water?

A https://en.wikipedia.org/wiki/Hydrofoil is a wing that produces lift in water.

Compressibility is only relevant in aircraft once they start getting near the speed of sound.

How about ground effect for helicopters (or hovercraft)?

Works just the same underwater. (Inviscid, incompressible). Low Mach number means compressibility is not significant. High Reynolds number means viscosity is not significant. Same for other dimensionless numbers and physical phenomena (Froude number etc).

Though note: compressibility is not the same as "exerting pressure". A hydrofoil or marine propeller works on pressure differences, even though the fluid is effectively incompressible.

For laypeople and casual sailors, thinking of the rudder as just redirecting water is good enough.

But water and air are both fluids and the same aerodynamic/hydrodynamic rules apply.

A rudder on a boat or airplane is symmetrical in cross section; the chord on both sides is equal. Wings and hydrofoils are asymmetrical; usually the “top” has a deeper chord than the “bottom”. But rudders are a still a kind of wing in that they generate a useful force by redirecting a fluid and thereby inducing a pressure differential. The pressure differential between the two sides is what causes lift - vertically with wings/foils and horizontally with rudders. If you think about it, this makes perfect sense – it would be silly to think that rudders and ailerons and elevators obey different laws than wings. In fact, one of the first things you learn as a racing sailor is that the sails themselves are wings - they’re not “parachutes” as commonly believed.

Anyway, my point was that you can stall a rudder just like an airplane can stall its wings- if the angle of attack is too high.

Stalling, the rudder, most commonly occurs during a round up, if you’re familiar with sailing with spinnakers. The rudder in that case is no longer able to generate enough lift (turning force) To counter the turning force, imparted by the force on the spinnaker forward of the center of mass of the boat, and the boat turns uncontrollably.

I am just speculating, but if the rudder became very misaligned compared to the direction of the ship, then when power was restored, the rudder might not be able to establish laminar flow and therefore would be stalled and unable to provide turning force.

It might be confusing to call the rudder a wing though, since there is no lift at 0 attack angle.

True. The main reason I keep calling it a wing is to reinforce the concept that it works by producing lift.

To your last point - sailboats move in response to the sum of the forces on them. Most sloops are designed to make it easy to balance the forces of the jib and the main, so that the center of effort is near the center of mass. If the sails are trimmed in this fashion you need very little rudder input - in fact it is easy to steer the sailboat with just the sails, if they are well trimmed.t If you let the jib a little out of trim, the force it imparts on the boat will decrease, and since the force on the main is constant, you’ll turn to windward. Likewise you can ease the main to turn to leeward if the sails are balanced and the rudder neutral. Handy trick if your rudder gets damaged.

An interesting note is that well-designed sailboats are designed to round up in the case where the headsail gets overpowered. As the sail gets overpowered, the boat will naturally try to turn away from the wind and also will heel further. The heeling of the boat will cause the headsail to lose lift and spill air before the main sail does, and the keel, which normally generates lift and drag to counter sideslip, combined with the now-more-powered mainsail, Generate a strong leeward yawing force aft of the center of mass which causes the boat to turn sharply into the wind. Rounding up only happens when you are losing control of the boat so turning into the wind ends up putting you in a safe mode where you can recover. There are a few boats out there where the keel is too far forward and/or the main spills air before the headsail; these boats round down in uncontrolled situations and can jibe unexpectedly – very dangerous.

>aerodynamic lift is a byproduct of air being a compressible medium

This is not correct.

I wonder if the "prop walk" effect might be stronger in shallow water.

>I have to protest here. Reversing and using the rudder on a 40ft boat works perfectly fine. I've done it on multiple sailing boats. You need to hold tight so that the rudder wont slap you if using a stick.

this is a stupid argument from all users , comparing a 40ft sailboat to other 40ft sailboats is like making a broad assumption about cars when comparing a dragster to an SUV simply because they have a similar singular aspect.

ANY sailboat, regardless of size, can have poor reversing performance just simply due to its hull shape and rudder plan. Some boats famously cannot reverse with authority due to the turbulence created between the parts. Some boats use feathering propellers which collapse inwards when reverse is applied in order to make a more efficient sailing experience, which effectively makes propulsion reversing useless.

There is NO generalized '40 foot sailboat' in existence. They all act different, and there are some that are perfectly capable of doing what other 40 foot plans might consider IMPOSSIBLE.

Since they were still moving forward while gunning it in reverse the rudder would still operate normally. They generally have bow thrusters too. I have no idea whether they could have been operational with the broader power/engine failures but if they were available I'm sure they were being used as well.

The question is what is the velocity of the water moving over the rudder? If forward velocity and the current due to a reversing prop cancel, then the rudder can't do anything.

>entails shutting down the engine and restarting it in reverse. This can be done with a two stroke engine.

Funny, I was starting a 2 stroke chainsaw a couple of years ago. I yanked the cord, it kicked back, pulling my arm back down but the saw started up and ran anyway. But it would not cut at all. I killed it and restarted it and noticed the chain going the other (right) way and it was now cutting fine. It has started in reverse the first time!

This is actually common for a 2 stroke type engine and used in things like gas golf carts and snow machines. The direction the engine is started is the direction it runs.

So to accomplish this for propulsion, you'd add a reverse polarity switch for your starter and you're good to go.

You can even get a (2-stroke) Detroit Diesel to run in reverse.

You don’t want to do it very long, because they don’t make oil pressure in reverse.

> You don’t want to do it very long, because they don’t make oil pressure in reverse.

US energy policy has entered the chat.

Yeah, in theory, there's not a lot about an engines running direction that matters, its all the stuff that's hooked up to it.

As you start getting into more complex engines, where you have fuel injection, timed spark plugs, oil pumps, transmissions it becomes untenable, but not because a v6 can't run backwards but because you'd have to rebuild and time all the support systems.

A low speed marine diesel like you'll find in a large container ship is not your granddaddy's 6V71. They are complicated, yet simple. They are indeed direct drive (possibly through a reduction gear) and they do indeed operate both in forward and in reverse. See e.g. [1].

[1] https://chiefengineerlog.com/2022/06/24/main-engine-fixed-pi...

Yes, defiantly not saying that's not how these work, and I do know that large boats tend to be direct drive. I'm just pointing out that most engines could do this and the limitation is generally how it interfaces with the external components and not as much a function of internal combustion type engines.

For example, a transmission would expect the engine to always run in the same direction, but given correct fuel and ignition timings, it doesn't really matter which way the crankshaft is turning while things are running.

I accidentally installed an injector pump 180° out of time on a MB OM617 and it "ran" kinda.. with a massive white smoke screen. I was shocked it even started.

I docked in reverse multiple times, same as parking a car in reverse. Just need water flowing along the rudder (from motion, not prop wash), but otherwise it's a great way to turn into tight spaces. Gotta be careful about prop walk, which will dominate the controllability until some reverse speed is established. So until you've decelerated to 0 and re-accelerated in reverse, you don't have much control beyond prop walk.

On ships like this the propulsion is separate from the steering. There is a separate rudder that is close to, but not attached to the prop and propshaft. The propshaft is fixed. The rudder doesn't just "restart in a random position" it would remain in the previous position unless there was a physical piece that broke in the rudder gear.

The fact that ship was able to reverse hard ( as evidenced by the slowdown), indicates to me that the prop was most likely still attached to the propshaft and hadn't flown off to mangle the rudder.

We still don't know exactly what happened on board, but it is interesting to work through possible scenarios.

Pilots certainly have experience with ship handling of 100,000 ton ships, that's their job. Pilots coordinate the moves of multiple tugs to assist with docking regularly.

Was there a harbor pilot on board, or the normal ship pilot?

Were there tug boats helping with the exit?

I have often felt that the harbor protocols were overkill, but this is one of the times they could have helped.

All pilots are "harbor pilots". Crew members who control the ship outside of port are just called crew members (captain, first mate, 2nd Officer, that kind of thing), never pilot.

There used to be! See William Adams, "the pilot of Miura" or "Miura Anjin", inspiration for John Blackthorne in James Clavell's Shogun.

I don’t know Japanese and havent studied this so hopefully someone can correct me as well. But I dont think it would be right to translate this to the modern meaning of a ship pilot. It more loosely translated to “navigator”.

There are some seemingly good details here[0].

> In Early Modern Japanese there was a word 按針 anjin, literally “searching needle,” which referred to the process of using a compass. At the time, this was the main way in which ships were navigated and so, by extension, the word was applied not just to ship navigation, but also to ship navigators

It goes into more detail about things as well but that is the part that stuck out to me the most.

0: http://japanthis.com/2013/06/20/what-does-anjincho-mean/

The term is accurate. The man in question held the rank of "pilot major" which is a specific type of navigator: https://en.wikipedia.org/wiki/Pilot_major

^ see folks, this is how bots get eyeballs on things. 70 day old account finds a relevant topic and directs it to a show that's recently out

also does a shout-out to SONU Sleep mattresses a few posts back.

enough other posts in there to create doubt -- maybe this is a person. maybe this is a person who does marketing sometimes.

Shogun is probably my favorite novel, I've read it three times. I had a cat named Anjin-san.

I have a mixed relationship with my mattress, and I talk about the downsides in that very same thread: https://news.ycombinator.com/item?id=39757531

Apparently for you at the moment, any mention of a product on the market is a flag for a marketing AI. I suppose this comment too is just what a marketing AI would say.

This comment is just a veiled mattress ad :p

  All pilots are "harbor pilots".

In California, at least, that's not strictly true. They get paid quite handsomely ($400–500k as of a decade ago) to avoid hitting stuff in specific waterways around the Bay Area.

https://sfbarpilots.com

One had a nasty pill habit and crashed an oil tanker under his purview into the Bay Bridge.

https://www.justice.gov/opa/pr/guilty-plea-case-cosco-busan-...

There used to be two really tall redwoods in the beast bay that were used as Navigation Trees to avoid a submerged rock in SF bay, that later had to be blown up after the trees were felled.

https://en.wikipedia.org/wiki/Blossom_Rock_(San_Francisco_Ba...

I put in the quotes because the person asking the question picked the exact phrasing, which as we both pointed out isn't correct. They're just pilots. The normal crew driving the boat are crew, not pilots.

> All pilots are "harbor pilots".

I don't think that's true. The Suez Canal famously requires pilots, but isn't a harbour (I guess you could argue it functions as one). I've heard of pilots for the Great Barrier Reef which is even more not a harbour.

Also the Columbia River Bar Pilots (neither a band nor a drinking club.)

https://www.crmm.org/current-exhibits.html

Not my wording. I was responding to someone who was confused whether pilot refers to the normal ship's crew (it does not).

Once the ship is under way I don't think the tugs hang around. They are just for the push away from the dock and initial turns.

It's very typical for pilots to be required for all entrance and egress from harbors, much more than the initial pushaway and turning but for quite a long distance through the channel.

Pilots or tugs?

Pilots always, for most harbours - they are extremely well versed on local tides and currents and essential for many river mouths and locations with large tidal swings.

Tugs - quite often, but not always - depends on the currents, ship weight, and time of day.

Depends on the navigational requirements. Indirect towing using tugs as an extended rudder are sometimes used. Although I think it is more common in Europe which has a more modern tug fleet.

https://www.youtube.com/watch?v=stebWQNrv5Q

The incident has some similarities ti the Cosco-Busan. It hit the base of the bridge piers and bounced off. The bridge wasn’t damaged.

That one was due to pilot error. The point is the pilot was still onboard but he was impaired by medication, the captain and mates kind of engaged in dereliction of duties contributing to the accident.

Obviously it’ll be a while before we know what happened in Baltimore.

a Baltimore local harbor pilot was onboard from what I've read.

2x harbor pilots.

No tugs.

Harbor protocol was in effect.

There were tugs two tugs helping depart the dock and turn, until about 43 seconds in the video. 5:08 AM real time

The video referenced in the parent post stated that the two tugs assisting with undocking had already disengaged (0:54).

AP News [1] is reporting that harbor pilots were on-board and were nominally in control of the ship at the time of the accident.

[1] https://apnews.com/article/baltimore-bridge-collapse-53169b3...

Update: added timestamp, link

At this point in the journey, they were cleared of the docks but not the channel. There wouldn't be a docking pilot on board nor would there be any tugs. It was cleared and under it's own propulsion until it wasn't.

My sailors guess from the footage and the reports is diesel generator failure(s) resulting in loss of power, restoration of power, then loss of power again. Bypassing the diesel generator (which provides power to hydraulics too) and manually throwing the engines in reverse. The billow of black smoke. This could have possibly burned out an engine, blowing the camshaft or propshaft or transmission.

The reverse was too late as the ship was already heading for the bridge pylon. Even at full reverse, you couldn't slow it down fast enough. Tragic.

The ship's managers (which I believe means the company which chartered it from its owners, and were operating it) say there were two pilots on board:

https://www.synergymarinegroup.com/dali-imo-9697428/

Well then there were two pilots aboard to see it into the Chesapeake…

Still, a diesel gen malfunction would render them useless unless one of them was a diesel mechanic as well (we sailors often have multiple credentials).

I don't think even the best diesel mechanic can fix it in 3 minutes.

> There wouldn't be a docking pilot on board nor would there be any tugs.

There is likely a pilot onboard until it leaves the Chesapeake, well past the CB Bridge-Tunnel.

When I worked on cruise ships, a pilot boarded a few miles out from the Sunshine Skyway going into Tampa.

Do big container ships like this typically just have a standard propeller/rudder without some kind of directional thruster to assist in maneuvering?

https://en.wikipedia.org/wiki/Voith_Schneider_Propeller

Not this one.

https://en.wikipedia.org/wiki/MV_Dali

Propulsion Single shaft; fixed pitch propeller

For maneuvering in ports, Dali has a single 3,000 kW (4,000 hp) bow thruster.

Usually tugboats attend whenever a large container ship enters or exits a busy port, and the tugboats have directional thrusters. Port authorities prefer it that way because it gives them more control (since the tugboats tend to stay in the port).

any idea why tugboats weren't standard issue going out of the port considering the potential damage economic and social of accidentally destroying this critical bridge for Baltimore?

Tugs were involved in helping the ship leave, but they were released before the accidently.

The release was the decision of the pilot, who remaining in charge of the ship till the accident. If pilots are too liberal in their use of tugs, the ship owner becomes unhappy (because the ship owner ends up paying for them), and if they become unhappy enough, will stop using the port. I.e., pilots are under some pressure to keep the use of tugs to a minimum.

Note that it is probably the pilot who advised authorities to stop cars from entering the bridge minutes before the accident, which is why the only deaths were a team of 6 construction workers working on the bridge.

I am surprised that they were able to get the bridge closed in just a minute or two. Unless there is a standing action plan for this (there may be) that seems like a really fast response. Possibly there are gates/stop lights that can be activated remotely?

Apparently not: the MDoT dispatcher: "I need one of you guys on the south side, one of you guys on the north side. Hold all traffic on the Key Bridge."

https://youtu.be/gafDs7sxJqg?si=hvLselyX9FQSczOH&t=98

MDoT == Maryland Department of Transportation. Note that the pilots in command of the ship were also employed by the Maryland state government.

If tugboats had been attending Dali, would they have had enough thrust to correct Dali’s course when it lost power?

Probably! Their engines are quite powerful.

on a large vessel, I thought that the captain does not steer the vessel, just gives commands to the helmsman, and same with the pilot. So, in a certain sense, they don't have the direct skills that the helmsman does. And speed/power/direction are indirect through the engine room; it's not a like a little motorboat, all controlled in one place by one guy.

> How many pilots, trained or not, really have any experience with a 100,000 ton ship in a crash situation with responses where seconds matter?

I would expect anyone piloting such a ship in a harbor/under bridges. We requite airline pilots to train for many unlikely plane failures because the alternative is letting planes crash that we could have saved with better training.

You can train for it, then how many years into your career you actually experience such a scenario are you likely to act instinctually and recover. The best solution would be to improve autopilot assist as it will never forget how to correct (if possible).

Lol you're right, controlling a ship with human inputs is so hard that is was the inspiration for a Russian shipmaster to create PID control

But I believe no big ships use any kind of autopilot while near shore. they only use it in the middle of the ocean.

If it’s anything like airline pilot training, there’s periodic retraining and evaluation to make sure pilots have the right reactions in case of an emergency.

I wonder if they’re required to keep up training to the degree pilots are. It wouldn’t surprise me if they’re not.

Nope. The military, aerospace, and medical industries have all refused full automation in life-or-death situations with cause.

Isn’t that interesting when compared with ‘machines don’t make mistakes’ wisdom

You'd have to be either a complete headass fresh out of a coding bootcamp or carting around The Agenda That Ate Calcutta to fall for that line of bullshit. Anyone who's spent the wrong parts of their week debugging ought to intuitively grasp that machines are inherently error-prone.

You are not wrong, but nobody gave the memo to the boss of my boss.

I’ve done some sailing but have no real authority when it comes to vessels like these.

Friends of mine are pilots on the Thames (London) and I seem to recall one of them telling me it was over 10 years training before you could bring a big boat in. Pretty fascinating really - they figure out all the tides and weather and plan the route. On the day they board along with a sensor system that sits in the bridge and gives the position to a high level of accuracy.

Or you just use the tried a true method of recurrent training and simulator work like in aviation

Part of the emergency reponse they are drilled with in simulators are "memory items" that are literally memorized responses to emergencies, i.e. "reverse engines, drop anchor" this is to prevent freezing or indecision. Of course I guess that can still happen but they are trained to the point where it should be automatic.

> How many pilots, trained or not, really have any experience with a 100,000 ton ship in a crash situation with responses where seconds matter?

The crew would have know for several minutes that the collision was imminent. These things happen slowly, it wasn't like the bridge suddenly jumped out of the water unexpectedly in front of them. The tragedy is that the crew had no options to avoid the disaster.

>How many pilots, trained or not, really have any experience with a 100,000 ton ship in a crash situation with responses where seconds matter?

I would hope, given the economic and humanitarian consequences of a crash, that we have simulators for this

We have miniature physical simulators for it with reduced scale ships & environments.

https://www.youtube.com/watch?v=jplrbxI5GN8

Catastrophic engine failure doesn't sound like a problem that's resolvable in 60 seconds.

> How many pilots, trained or not, really have any experience with a 100,000 ton ship in a crash situation with responses where seconds matter?

I think you are missing the point.

Clearly I am speculating, but I don't think any more experience would have helped in this event.

Why ? I think what happened today was almost entirely down to not being able to fight the basic Laws of Physics.

Its a well known fact that enormous ships take an equally enormous amount of time and distance to reflect the actions of the captain. You make an input and you see the result a bunch of time and distance later.

Time and distance were, sadly, not on the captain's side today. Physics took care of the rest.

To continue the speculation ... as a ship that size is slow to turn or halt, that seems to suggest that even if the ship hadn't suffered a power failure then it would have passed quite close to the bridge pier anyway. Was that expected?

Yes, it was expected. Ports have "channels", essentially traffic lanes. Until the first power failure, the Dali was in the proper lane and would not have collided with anything if she had remained there.

I hope the next POTUS makes good on Biden's promises because Baltimore and Maryland will need federal assistance since they can't afford such a burden.

And I assume there will lawsuits to recover costs as this caused economic damage and risk to life (8 people unaccounted for at current time).

I'm kind of confused how a President can promise something like that. He doesn't have any power to appropriate money, and given his party's lack of control of Congress, I'd argue he can't promise anything.

Not to mention that one can scarcely find a "bluer" area than Baltimore -- I would assume that the most proudly right-wing politicians would be more than happy to let Baltimore suffer to score points with their polarized supporters. I hope it doesn't come to that, but they tried to block Hurricane Sandy relief, despite every hurricane in the South being an automatic 'non-partisan' emergency.

> It's my intention that the federal government will pay for the entire cost of reconstructing that bridge and I expect the Congress to support my effort

This is what he said. I would expect Congress to play along too -- just how unpopular would it be to abandon Baltimore??

Republican side probably doesn't care; Maryland voted 65% for a democratic party president.

Baltimore city and PG county voted for a democratic president. Rest of the state was red.

10 EC votes to Biden. 0 to trump and no hope of any in this year's election.

1/8 red house seats. The other 7 very comfortably blue.

The rest of the state doesn't seem like it matters much to the only results they'd care about - seats and EC votes.

It doesn’t, I agree. Just pointing out that whenever Baltimore figures out Democrats have been fucking them over for decades maybe something will change.

Edit: not that Republicans are any better.

> just how unpopular would it be to abandon Baltimore??

You underestimate how much vitriol is coming from the Right about Democratic-leaning cities. Baltimore is 60% Black and voted 87% for Biden in 2020. Baltimore isn't on the top of the list of cities they like to claim are failures, but just wait.

My dad is deep in the Right-wing media econsystem and he is convinced that the downtowns of Portland and San Francisco have been burned to the ground and the entire region is a lawless anarchy.

"- just how unpopular would it be to abandon Baltimore?? "

I mean I'm from the Baltimore area and.. well.. I mean some of us would consider that town somewhat abandoned already, think Detroit. It has some pretty rough parts. With the main triggering event being 60s/70s loss of steel industry (Bethlehem Steel). Of all the big east coast cities (Boston, DC, NYC, Philly, Baltimore) I would say Baltimore is the most abandoned already.

> just how unpopular would it be to abandon Baltimore??

As someone else posted above, Baltimore is a massively important US seaport, that moves tons and tons of goods.

Even the most pro-business Republican realizes that a lot of industries are going to get hurt, and in places far away from Baltimore, if they can't move freight through there.

He'll need to get Congress to pass an appropriation, yes, this is his way of putting pressure on them to do it. I think that there are emergency funds already appropriated that he can immediately tap, but they would fall way short of the cost needed to build a new bridge. The damage here doesn't just affect Baltimore, the national economy is affected.

Industry has the power here.

This seems like a system architecture error. Boats do weird shit sometimes and so bridges need to be deigned to not fall down when a boat crashes into them. Requiring a huge boat to be steered to meter resolution when clearly that's not always going to happen is top shelf stupidity. Up there with backup generators in the basement below the water table.

My civ engineer friend says that bridges are supposed to have barriers in front of their pylons for this particular reason - in the event of a collision, the barrier would be destroyed but not the pylon.

I can’t find any bridges which have a barrier that can protect against a fully loaded container ship. I have seen plenty of barriers which would protect against personal watercraft and smaller working ships like smaller tugs/coast guard ships/shrimping boats, etc.

But a loaded container ship at 8 knots is not going to be stopped by anything remotely feasible.

Container ships weigh between 50,000 and 220,000 tons. A US aircraft carrier weighs 100,000 tons.

https://en.wikipedia.org/wiki/Dolphin_%28structure%29?wprov=...

If they're designed to stop a bulk carrier then presumably they can stop a container ship.

That article gives an example of being hit by https://en.wikipedia.org/wiki/MV_Summit_Venture

deadweight tonnage of 33,912, gross tonnage of 19,735, and a net tonnage of 13,948.

The one that took down this bridge:

https://en.wikipedia.org/wiki/MV_Dali

Her registered gross and net tonnages are 91,128 and 52,150, respectively, and her deadweight tonnage is 116,851

Many times larger.

Closer than I expected though! It’s possible there are some out there made for this scenario.

The Key Bridge had dolphins but not fenders, some descriptions since the incident have indicated that it has fewer dolphins than some other bridges.

Some bridges have fenders, my understanding is that with existing brudges whether they can be retrofitted, even if resources exists, depends on the channel and the kind of traffic it needs to handle, because they take up soace that can be nontrivial in a tight channel.

They do. I would think that that bridge certainly did as well, it’s part of a busy port. It’s not exactly hard to imagine it happening.

My guess, and it is a total guess, is that the protection on the bridge was nowhere near sufficient for a ship of that tonnage.

I’m assuming it was built to whatever the correct standard was when constructed in the 70s. I’m also assuming the ship weighed far more, or perhaps traveled noticeably faster, than the cargo ships going into the port back then.

Basically I’m guessing it needed an upgrade in its protective barriers but it wasn’t recognized or hadn’t happed if it was.

Top shelf stupidity is thinking a container ship’s momentum can be stopped by normal barriers.

I’ve see pictures of the barriers before the accident and they were there, but they looked like they were tailored to 70s era ships not the container laden ships of today

> Baltimore had $350 million of insurance.

Wouldn't the ship's insurance be the one paying here?

Baltimore's insurance will probably sue the ship's insurance if I had to guess.

I bet we will see a General Average play out. Gonna be a legal mess for years to come.

https://en.wikipedia.org/wiki/General_average

I've driven a number of vessels, ranging from a 17' dinghy to a nuclear aircraft carrier and have a number of friends who have been involved in accidents one way or another. I have personally not had the conn during disaster, but have been an engineering officer and a legal officer responding to them, on my ship. To be honest, steering a ship under most conditions is not hard. The anxiety-provoking issues are 1) poor bridge team management (aka toxic leadership) and 2) engineering disasters, which this appears to be.

This

> Similar to a car that hits ice, wheels have arbitrary alignment when they reengage road, when power starts being delivered again, car swerves towards concrete barrier even with brakes. Driver with limited crash experience is mostly just panicking and stomping.

is almost certainly not the case on a large ship. The rudder is rotated hydraulically. Loss of power simply causes the rudder to stop moving, it's effectively "stuck". Some ships have manual override using a massive wrench, but it takes hours to move the rudder meaningfully in that situation.

As for this:

> How many pilots, trained or not, really have any experience with a 100,000 ton ship in a crash situation with responses where seconds matter?

Probably way more than you think. This is a significant reason why they seem so calm when they show up on the bridge. They just hopped from a relatively tiny pilot boat or tug onto a massive ship, possibly with significant sea state. This can be some Indiana Jones level crazy.

https://www.youtube.com/watch?v=18VF8WXWfZw

https://youtu.be/C8ER9Ladqg4?si=Ijwhu90iJi8WPAas&t=226

Pilots are very seasoned mariners who have seen multiple losses of power, and pretty much everything.

Now, back to point 1: bridge team. I have seen a captain the crew trusts execute flawless maneuvers even in exigent circumstances. I have seen a captain the same crew doesn't trust fail repeatedly at everyday things.

We don't have the whole story yet. What happened on the bridge? What happened in the plant? Why did power drop? Did they flood an online generator with diesel oil? I ask because I've seen that happen. Did they blow an exhaust manifold? Seen that. Did they trip the plant by getting preparatory checklist work backward? Seen that. Did they go all back full immediately? Possible that they couldn't ring the order if they dropped power. Was there panic on the bridge (bad sign) or was there grim fortitude to process checklists that would never help (better sign). In any case, no doubt the captain is done. Probably happy to never drive a ship again after that, tbh.

Quite amazing videos. I've no experience in this domain and so it makes me immediately wonder - is there no risk of substantial damage from those ships colliding due to a wave hitting e.g. the smaller ship just right and pushing it hard against the larger one?

I am not an expert, but clearly pilot boats must be built to take a lot of punishment. And they don’t have the mass to damage the big ship beyond the paint layer.

I agree that it seems that must be the case. I'm just curious where my assumptions break down - whether I'm overestimating the mass of the pilot boat, overestimating the force a single perfect wave can impose, or underestimating the thickness of these ships' hulls.

I've just always be impressed by the amount of energy that boats impart when they collide with anything. Like in this case, the entire bridge was brought down by a collision at under 8knots. Obviously that ship had orders of magnitude greater mass than the little pilot boat, but presumably you want to avoid even dinging up the larger ship, and so that's an orders of magnitude smaller goal as well.

Well, here’s a story to give you an idea. In November 2018, a frigate collided with an oil tanker on the Norwegian coast. It was only a glancing collision, involving the starboard side of the frigate and the bow of the tanker. The frigate was severely damaged, basically having much of the starboard side ripped open, and it eventually sank. You could hardly see any damage to the tanker. (Luckily, or perhaps miraculously, no one was killed or seriously injured.)

Back to the pilot boat: Steering one in heavy seas when trying to deliver or recover a pilot is clearly a difficult art. But at least in the videos shown, there doesn’t seem to be much of an impact between the vessels. I am sure that is in part due to the skill of the steersman. Besides, I am sure the pilot boat will have permanently mounted fenders all around.

Since you have experience in boats of this magnitude, did it make sense not to have tugs minding the ship until it passes under the bridge since it's pretty obvious through common sense what the alternative is when there is a catastrophic engine failure? Would tugs even help if they'd been around during a catastrophic failure of the boat engine(s) making my question a stupid, ignorant one?

I don't know the rules for the Port of Baltimore, but tugs aren't generally required for channel transit. It's the berthing where tugs are generally used: the ship needs lateral thrust to lay alongside a pier or quay wall. Some ships have bow thrusters or APUs but a ship this size would definitely have tugs for the mooring.

Admittedly very naive question: would they have an anchor? Would it be long enough to hit the channel bed? Could dropping it have helped prevent, or at least slow down, the ship?

Or even if so was it just too late when it all went down and it wouldn’t have made a meaningful difference?

Given the forces involved, dropping anchor probably would probably massively damage the ship without sufficiently arresting its momentum, and add another uncontrollable variable into its trajectory.

The video linked above shows that the vessel had dropped anchor. However, anchors aren't very effective at that speed. They will just drag on the bottom or the chain will snap. There's just too much momentum.

I'm once again impressed that subject matter experts are out there on every topic, and they are often capable of quickly and accurately disseminating information about an event far better than the local news.

Do you have recommendations/other channels with experts like this?

> event far better than the local news.

That’s such a ludicrously low bar that I’m not even sure this would qualify as a compliment to these alternative producers.

One might expect that local news are well connected with those who actually did construction, planning and whatnot of such projects, or emergency responders, or disaster mitigation, or people specialized in local geology / hydrology to show up challenges...

The sad truth is that "local" news more often than not barely has any local people any more, a lot of content is directly ripped off from others (especially fire dep't or police reports, with the added problem that no one challenges the copaganda), or not local at all but produced/sourced by central agencies, or theoretically "local" reporters have such large areas to cover that they can't reasonably build relationships with experts.

    > One might expect that local news

No. Local news is free over the air. Thus, it is paid for by advertising. Thus, you (the watcher) are the product. Hence, it is low quality. Local news is interested in producing as much clickbait emotional content as possible to drive up viewership. See: CNN, Fox News, MSNBC. All are "free" and terrible for depth of their reporting.

I don't know about local news, but other news sources interview lots of those experts.

The local sailor/professional mariner bar in Newport will be interesting tonight!

How much of this is falls on the protocols of the shipping company? I.e. the same shipping companies that gouged the planet during covid - did they strip away safety protocols in order for profits/expediency?

Is this similar to Boeing for the shipping world? I realize it is early to come to any conclusions.

The question of this being a rare one off vs container companies deprioritizing safety protocols is what I am interested. The power failures make me go down this logic of thought.

Boeing makes and sells planes, they don't fly people.

Maersk/ZIM rent container ships from another company who makes them and drive them around.

These are completely different companies. A more correct comparison would be something like Jetblue or American Airlines.

But I seriously doubt there is the result of some kind of profit hungry CEO. However I cannot with 100% say it's not until we find more details. But I feel confident enough to avoid the tin foil hat.

Can anyone say if there is the slightest possibility that this was caused by an Cyber attack?

As an inland armchair-captain, I want to admonish that tugboats should probably always be stationed around bridges to intercept such off-course mariners.

It seems much more reasonable to only disengage the tugboats that were already helping the container ship get under way once it clears navigation hazards like the bridge, instead of keeping 24/7 quick-response tugboats at the bridge that try to intercept an out of control ship in a bare few minutes.

Moving large boats across water is slow. The Francis Scott Key bridge was 8600 feet long, or 1.4 nautical miles. AFAICT there were just over 4 minutes from the time that the first power outage started until the ship struck the piling.

A modern harbor tugboat can go perhaps 15 knots. In 4 minutes this means it would travel 4 nautical miles, at the very best (running start in correct direction).

So let's say that there would have been 4 minutes for a tugboat to (1) become aware of the problem, (2) travel to the location of the ship, (3) figure out what it needs to do, (4) maneuver into position [keeping in mind it might need to move to the other side of a 900' ship moving 8 knots] and (5) move the ship. And this assumes that the tugboat was idle in the first place.

There just would not have been enough time to do anything meaningful if the tug wasn't already right at the ship, on the correct side.

Thank you for putting it into numbers!

> A modern harbor tugboat can go perhaps 15 knots. In 4 minutes this means it would travel 4 nautical miles, at the very best (running start in correct direction).

It's probably pedantic, but I don't understand your math. Knots are nautical miles per hour. To travel 4nm in 4 minutes would imply a speed of 60 knots. At 15 knots, you would travel 1 nautical mile in 4 minutes. (15kn/60min * 4min = 1)

Or it's possible I haven't had enough coffee.

I made a math error but couldn’t correct it after I had votes - 15kts for 4min = 1 nm.

Other photos of aftermath shows an anchor dropped. Was wondering if he dropped anchor before the impact.

update: anchor was on the other side furthermore that anchor wouldn’t help much in last 45 seconds at 7.5 knots.

The ship dropped anchor btw when power Temp came back on as part of its procedure which is why you see the quicker directional change at end

It's fairly horrifying how fast the bridge collapsed after the moment of impact on the pylon. The whole span seemed to fall in totality almost at once. If anyone was on that bridge at the moment of impact, they were in the water a couple of seconds later.

Not that it matters to anyone else, but having driven across that bridge dozens of times with my kids, this is just shocking. It’s one of the main corridors in the area. Thank god it happened in the middle of the night, though that’ll be no consolation to the families of those who may have died.

I don't think that's quite right. People in Dundalk will suffer a fair bit, as will folks in Glen Burnie and Annapolis, but most people are going from DC to Delaware, and go north rather than over the Key bridge.

I think this is most harmful for commuters.

Blocking the Baltimore harbor is brutal although I suspect the passage will be cleared as quickly as possible.

I think 30-35k cars a day cross that bridge. Being local to the area, is is going to make traffic in the entire metro area much worse, and it is already awful.

Report from CBS News mentions the bridge handled "11.5 million" vehicles a day.

EDIT: That number seemed fishy; I think the reporter is referring to the traffic along the entire I-95 corridor.

https://x.com/CBSNews/status/1772556368106450953?s=20

It is between 30-35k/day, about 12.5 million/yr.

LOL, that figure is clearly off. That's double the population of the entire state!

Per another comment it's much closer to correct for the annual number of vehicle crossings.

One way to assess these numbers is to conduct a quick sanity check. How many cars per minute or second would this be?

11.5 million cars/day is equivalent to :

  ~48,000 cars/hour
   ~8,000 cars/minute
     ~130 cars/second

Clearly, somethings ... a tad off.

11.5 million cars per year however works out to:

  31,000 cars/day
   1,300 cars/hour
      21 cars/minute

Or roughly a 3 second headway per vehicle. Given four traffic lanes (two in each direction), that would be a vehicle every twelve seconds per lane, which seems far more reasonable. That's spread out over the day, so peak-hour traffic would be much higher.

Peak capacity for a highway lane is just shy 2,000 vehicles/hour:

<https://www.mikeontraffic.com/numbers-every-traffic-engineer...>

Which would put the Key Bridge's maximum capacity at about 192,000 vehicles/day.

For comparison, the San Francisco-Oakland Bay Bridge saw about 42.7 million paid toll crossings. As these are metered only in the westbound direction, actual crossings are likely double that, or 85.4 million/year, or about 230,000/day.

(The bridge sees 1/3 the total traffic of all California state-owned bridges.)

<https://mtc.ca.gov/operations/programs-projects/bridges/san-...>

Local to the area. This was devastating news to wake up to. I don't know what's wrong with me but seeing this and knowing there were casualties made me cry.

Edit: Maybe I'm just tired and need more sleep.

No shame in feeling human friend

It is shocking and that does not sound like an inappropriate response.

Hey, don't be too hard on yourself. I'm feeling it too, all the way from Medfield. It's a loss.

There’s nothing wrong with you. It’s okay to sit with these feelings.

> I don't know what's wrong with me but seeing this and knowing there were casualties made me cry.

I think that's called "having feelings". Nothing wrong with it.

It’s called being human.

I worked next door to the church that was shot up in Charleston and felt similarly moved despite not knowing them, never having been inside the building, and not having even been a Christian at the time.

It is a bit strange at some level - not having any true connection beyond proximity but you should probably worry if you _don’t_ at least feel a little something.

>I don't know what's wrong with me

I would be much more concerned if you didn't feel devastated by this and you didn't want to cry.

What you're describing is a normal human reaction to a tragedy.

Nothing wrong with crying. I cry sometimes. Heck, if I spend too much time thinking about the 343 firefighters who died on 9/11, it will still bring a tear to my eye even after all these years. It's just part of the human condition. Cherish it.

Do you happen to know how they stopped traffic? Are there warning lights at the ends of the bridge? I have seen bridges of this sort but they are fairly rare.

I'm wondering if that's how they stopped almost all of the traffic. Flip a switch, most people stop, a couple of assholes blow through the caution and FAFO.

Based on comments elsewhere two police cars were able to block traffic with mere seconds before the impact. There was a construction crew on the bridge repairing potholes so the police may have already been nearby related to that.

That was my exact thought. Thankfully, I woke up to messages that my family members were safe and sound. I hope they find everyone but at this point it seems unlikely.

I agree. I lived in PG county for years and this is a big deal

The 295 bridge collapse a decade ago was similarly shocking

U.S. infrastructure is beyond crisis level.

I'm not sure if I would expect any bridge to survive being struck by an enormous container ship.

Older bridges no, but newer bridges should absolutely. The Bay Bridge was struck in 2007 and came away mostly unscathed due to earlier efforts to prevent catastrophic damage in that scenario;

https://en.m.wikipedia.org/wiki/Cosco_Busan_oil_spill

Though the Maryland accident looks like it struck it dead on - just a massive amount of energy to absorb.

Glancing blow of the Cosco Busan was a big deal but it wasn't a direct impact. Different order of the magnitude of forces that impact. Not comparable.

'The Bay Bridge' refers to something else in this part of the country.

https://en.wikipedia.org/wiki/Chesapeake_Bay_Bridge

Hacker News:California::Internet:USA

It's assumed that everyone comes from California unless proven otherwise.

In my defense, the SF-Oakland Bay Bridge is older and carries more 4x more traffic than the "other" Bay bridge! But yeah, given that the Chesapeake one is just down the road from the bridge that collapsed, I get the confusion.

> SF-Oakland Bay Bridge is older

In a Bridge of Theseus sort of way. The entire Eastern span is very new, a lot of the approaches have been rearranged, and major components of the Western span has been replaced over the years. But I guess none of this affects the age of the bridge, at least in Wikipedia’s estimation :)

This is why I come to HN, for Ship of Theseus references.

Yes. Dolphins and protective features for this sort of scenario are more standars now.

The container ship "unluckily" maneuvered between the protective barriers. About 4 more protective barriers would have stopped this collapse.

------

No bridge survives being struck by a container ship. That's why barriers are erected around critical points. There already were barriers, they just weren't complete coverage for some reason. (EDIT: Maybe the older 1970s era design of this particular bridge wouldn't allow more protection to be placed. Obviously this situation calls for a full investigation / lessons learned kind of thing, as part of the new bridge building process)

A lot of bridges have their pilings set on mini islands, terrifically reinforced piles of stone and concrete that extend for quite some distance around the actual support. I don't know why some are built without that, it always weirds me out seeing the spindly legs going straight into the water, and this is why.

Edit to add: Check out Fort Carroll, precisely such an artificial island just a few hundred yards away in the very same harbor. It was built in the 1840's as a military position to defend the harbor, and has fallen into disuse. Now just imagine if the bridge sat on a couple of those, instead of the foundations it had. Ship would've barely dented the wall.

Civil engineering is very complex and doesn’t go off of feelings. I’m sure the type of soil and rock that the bridge is built on inform such decisions.

There is this other thing that’s very complex- getting budget from the local government to fix something

I would and furthermore I think there is a massive bias at play - if the exact same disaster happened in China there would be jokes about bridges made of Chinesium.

There is an expectation that a disaster happening in the west in a result of unforeseeable act of god, but in China it will be a result of corruption or shoddy workmanship.

Whereas in reality maintenance standard in the west have fallen but in the east they improved.

So now this bias protects responsible decision makers from legal consequences - no one went to prison for grenfell disaster, postmaster scandal or the Boeing debacle.

> Whereas in reality maintenance standard in the west have fallen

In the context of this incident, are you saying that we _previously_ used to go around retrofitting our 50-year-old bridges with more modern defenses, and then at some point since then we stopped doing this? Obviously if we're talking about new construction, it stands to reason that standards have only _increased_, but this was an old bridge built to old standards. So which standards have "fallen" to result in this disaster specifically?

Literally, yes, someone is responsible

> 46,154, or 7.5% of the nation’s bridges, are considered structurally deficient, meaning they are in “poor” condition. Unfortunately, 178 million trips are taken across these structurally deficient bridges every day

That doesn't answer the question I asked regarding the specific claim that maintenance standards have fallen.

For example, it's possible maintenance standards never changed and the old bridges simply got older and more exposed to risk as the years went on.

Well everyone involved in the design of this bridge is long dead.

> I'm not sure if I would expect any bridge to survive being struck by an enormous container ship.

Not a container ship, but an abandoned bulk carrier ship: https://g1.globo.com/rj/rio-de-janeiro/noticia/2022/11/14/po...

That bridge survived with little damage, and was reopened the following day after small repairs (https://g1.globo.com/rj/rio-de-janeiro/noticia/2022/11/15/te...).

Growing up my grandmothers house was on the watet across the Bay from Baltimore. This bridge was literally in the backdrop of my childhood. Scary stuff.

Memories of the Minneapolis bridge collapse.

I lived <1 mile from it at the time it went down, and had crossed it earlier in the day on my commute.

Yeah. I was out of town hiking in Wyoming at the time and was told it was the 35E bridge by a passing hiker who relayed the news to me. My mom drove the 35E bridge twice a day. I couldn’t hike out and call home fast enough. I didn’t know anyone who was on the bridge when it fell but I do know many who missed being on it by minutes. Scary stuff.

I remember standing not far from edge of that shortly after it happened (https://www.flickr.com/groups/35w-bridge-disaster/), and still get a little panicky when I'm in slow traffic on a bridge. This event will affect the city, the port, and its people for a long time.

I was incredibly worried about my dad, he's a truck driver and drove that bridge just an hour prior to this happening.

I'm hearing there were at least 20 cars and a truck on the bridge, plus construction workers, at the time; my heart goes out to those families

Glad to hear your dad made it across safely.

According to current reports, the Maryland Transportation Authority Police responded to the ship’s “mayday” and stopped traffic in the minutes before the catastrophe, but 6 construction workers are still unaccounted for.

https://www.baltimoresun.com/2024/03/26/key-bridge-collapses...

They keep reporting this, and maybe it was because the video was sped up, but it looked like there was still traffic going across until very close to the collision

The last car crossing that I can see clears the span about 1:28:06; the bridge collapses about 1:28:48. That's about 40 seconds of gap between the traffic and the collapse.

I haven't timed how frequently cars are coming, but it seems to be about every 30 seconds or so, which--combined with the time it takes to cross the bridge--is evidence that a bridge closure was effected just before the bridge collapse.

Whoever was driving that last car had better go buy a lottery ticket right away.

Why? They already used up all their luck escaping the accident.

Gambler's fallacy says the amount of luck should remain constant

The optimist's gambler's fallacy says luck is a constant attribute of an individual, and if someone gets lucky they are more likely to have a high luck stat and thus be more lucky in the future. The pessimist's gambler's fallacy says luck is a consumable resource, and if someone gets lucky they consume their luck and are thus less likely to be lucky in the future.

I have to acknowledge that I did not fully understand the lottery-ticket-buying trope until now.

Honestly, that would probably fuck me up for a little while, knowing I was less than a minute away from probably being dead. I hope they're okay, mentally.

There's a pretty good spanish film named Intacto that has something like this as it's premise: people who survive disasters have "luck" that can be captured/transferred by other people by playing games like russian roulette.

If the police were able to close the bridge just in time, that's a pretty spectacular response. There were only ~5 minutes between the ship loosing power initially and the impact. The police saved lives, and it's only a shame that the construction crew wasn't evacuated in time.

Looking at the MDOT website, the traffic incident closing the Key Bridge was posted at 1:27 AM.

The Washington Post has police audio at the time of the closure (https://www.washingtonpost.com/dc-md-va/2024/03/26/baltimore...). A quick summary of the timeline from that audio:

* There was a request to close the bridge when the ship lost power, which went over police dispatch about a minute before the bridge collapse (the bridge collapse is reported at timestamp 1:09 in the audio).

* Someone was able to hold the outer loop traffic at ~0:20 in the audio, as they reported they were already driving along at the time.

* Inner loop traffic is reported stopped at ~0:56 in the audio. I suspect there may already have been a police car there because of the construction on the bridge.

* Between 0:20 and 0:56, the conversation is about pulling the workcrew off the bridge. The police officer blocking inner loop traffic, after reporting stopping traffic, is indicating that he's waiting for a second unit to arrive before going onto the bridge to collect them.

* At 1:09, the bridge is reported collapsed, and multiple officers confirm. There is a question as to which traffic is stopped--the people blocking inner loop traffic are unable to confirm outer loop stoppage, but the person holding outer loop informs them of the stoppage at the end of the recording.

So traffic seems to have been stopped for about 10-50 seconds before the bridge collapse, depending on the exact length of time between someone stopping traffic and radioing in that they did so. From what I can tell, it sounds like outer loop traffic was stopped in time solely by sheer coincidence, while the inner loop traffic may have been existing police presence (for the construction zone) changing posture to a full closure.

Do you know what inner loop and outer loop traffic means here? Are they different sides/directions of the bridge?

And it is tragic how close the police were to evacuating the work crews. I interpret that the officer blocking one entry intended to go on to the bridge but was waiting for another cruiser to block the bridge before he left. A few more minutes and the bridge might have collapsed with no casualties. Though at least an officer attempting a rescue wasn't hurt.

The bridge is part of I-695, which is a beltway: https://en.wikipedia.org/wiki/Interstate_695_(Maryland). Inner loop refers to the inner lanes (traveling clockwise), outer loop the outer lanes (traveling counterclockwise).

Further clarification: because it is a loop, you can't use cardinal directions ("East bound I695" for instance) to indicate which lane you are talking about.

There is a semi-truck that enters from the right just before the crash at https://youtu.be/N39w6aQFKSQ?t=299 (4m59s). And some more vehicles that follow after. Doesn't seem like they stopped "all" traffic as is claimed.

Somehow I find it surprising how completely the bridge collapsed after the damage. I understand that a container ship collision is serious, but you could imagine a scenarios where the bridge slumps or buckles but doesn’t just disintegrate like that. It’s surprising that ships capable of doing this damage were probably regularly driving past it, and its safety as a thoroughfare depended entirely on those collisions not happening.

Does anyone know if modern construction standards would require more stability after a ship collision, or is this still how we build bridges?

Modern bridges are required to endure a collision. This bridge might be very old and not sufficiently maintained against current requirements.

It opened in 1977. So, oldish, but not that old. Plenty of far older bridges around than that.

https://en.wikipedia.org/wiki/Francis_Scott_Key_Bridge_(Balt...

Notably predating the 1980 collapse of the Sunshine Skyway after a ship hit.

Neat how they made what was left of the old bridge into a giant fishing pier!

I'm not sure how many brand new bridges would stay up after having one of the piers on the main span removed.

The trick is to make sure the piers are not removed. For example, the new Tampa Bay Sunshine Skyway Bridge (rebuilt after a similar disaster):

> In addition to a wider shipping lane, the channel would be marked by a 1⁄4 mi (400 m)-long series of large concrete barriers, and the support piers would be protected by massive concrete "dolphins".

https://en.wikipedia.org/wiki/Sunshine_Skyway_Bridge#/media/...

Good view of them on Google maps

https://www.google.com/maps/place/Sunshine+Skyway+Bridge/@27...

Collision with what? I'm pretty sure that with a sufficiently massive ship sailing fast enough, one could take down any bridge. Hence I'd think there are limits which ship may approach at a given speed. Was one of those limits perhaps exceeded?

Collision means nothing without magnitude of force.

A glancing blow is completely different from a direct hit. And the amount of Newtons behind the blow completely changes the outcomes. A small ship versus a loaded container ship is a completely different force.

I doubt many bridges would take a full speed, fully loaded container ship directly to one of their supports and survive it. Certainly the most celebrated bridges have a better chance of surviving but I doubt any second tier, lower traveled routes would.

Apparently this container ship was only half loaded to capacity. And it seems likely that a container ship would hit it given the vicinity of such container ships. I'm generally confused on this matter.

It hit the support completely dead on and stopped. All of that momentum and force went directly into the bridge. The pulse from that impact would have been enormous.

Why would you anticipate that a container ship would have to hit the bridge? What about the flip side to that... How many bridges have never been hit by a container ship or alternatively how many times have an almost fully loaded container ship come to a dead stop after hitting a bridge?

According to a quick search and reporting due to this event, apparently a quick number is a few dozen full collapses in the past 55 years, which doesn't seem to account for impacts and collisions that didn't result in full collapses. So that seems like a lot of bridges indeed, along with a lot of deaths and economic impact.

The reason why I would anticipate a container ship hitting that bridge is because of the video we've all seen. It's a huge ship that is going the slowest it can while still retaining control over the vehicle, unattended, through a tight spot, close to a bridge with zero protection from ship collisions, and all with a ship design that is apparently (according to other comments) effectively impossible to correctly maintain and keep running at all times. So I think the better question is, why wouldn't you anticipate a collision?

The problem is the static scheme of the bridge.

Most modern bridges are hyperstatic: if you remove one support, it still stands.

Or at least isostatic: you remove one support or one span, and nothing happens to the nearest ones.

This bridge was ill conceived: you remove one support or span, and it brings down everything like a chain that pulls down everything it's linked to.

It's bad because the "engineer" just wanted to show off.

You cannot put the entire weight of the 70's safety culture to an engineer "showing off"

I bet there was a much more complex and nuanced analysis which included crossing ship dimensions, budget, time to completion, available technology, composition of the local seabed etc..

Designing a bridge is proper engineering and not that easy.

> Any idiot can build a bridge that stands, but it takes an engineer to build a bridge that barely stands.

...in other words.

Believe me, an engineering student that sees that, immediately understands the problems after taking the first science of construction lessons.

You do need need the truss at all. If the truss fails (in any of the three spans), it brings down two adjacents spans.

It's just a show off.

There's been at least 50 years, probably more like 60 or 70, of advances in the art (much less pedagogy) that those students have and the bridge engineer did not.

The '70s were also a transitional period in bridge design where truss bridges were being phased out in favour of newer types of hybrid suspension bridge. Many of the iron and steel bridges of the 1890s through the 1970s were later replaced with suspension bridges or arch span bridges because they used less material and could be architecturally adapted to the area better. So some truss bridges were made as much for appearance as function in order to compete with the futuristic hybrid suspension bridges like the 1967 Ponte Morandi or the 1987 replacement Sunshine Skyway.

Not all bridges are this vulnerable to a single impact. This one, opened 12 years earlier, has a different style and mostly survived a cargo ship impact: https://en.wikipedia.org/wiki/Tasman_Bridge_disaster

I would say the damage is about the same, The ship knocked down a pier and all spans connected to the pier went down. The difference is, on the baltimore bridge is that the spans are a lot longer. But all other spans(the ones nearly out of frame) are still standing.

Parts of the Francis Scott Key Bridge not connected to the hit pylon went down too. The beam structure above the road that supports the whole thing collapsed and took down other spans.

Yes the entire truss section dropped. However the bridge is quite a few times longer than it's trussed section. and none of those spans dropped.

Maybe it's the extra momentum that took it over the edge, which if it were built in the 70s probably were designed with static loading in mind without the benefit of dynamical simulation?

And that structure probably existed because the bridge has fewer longer spans, probably since the seabed below the bridge is deeper (and needs to be deeper to support container ships passing below).

The Öresundsbron (connecting Sweden and Denmark) features both short segments but also with an overhand section in the middle for larger ships to pass through. (1) The great belt bridge (inside Denmark) is slightly higher but has the same kind of profile, one of the largest cruise ships barely making it under it is shown passing in the video below (2).

I think the simple truth is that we're vulnerable to these kinds of accidents unless we build far far sturdier bridges, but at these scales to allow passage of ships of these sizes the cost would just make many bridge projects prohibitably expensive.

1: https://www.norden.org/sites/default/files/styles/content_si...

2: https://www.youtube.com/watch?app=desktop&v=j1Cs0C8LkeU

The Øresundsbron is a bridge and a tunnel, and although it's not required most ships choose to cross over the tunnel rather than under the bridge.

I was curious about Zealand's other connection, the Great Belt Fixed Link:

> The West Bridge has been struck by sea traffic twice. While the link was still under construction on 14 September 1993, the ferry M/F Romsø drifted off course in bad weather and hit the West Bridge. At 19:17 on 3 March 2005, the 3,500-ton freighter MV Karen Danielsen crashed into the West Bridge 800 metres from Funen. All traffic across the bridge was halted, effectively cutting Denmark in two. The bridge was re-opened shortly after midnight, after the freighter was pulled free and inspectors had found no structural damage to the bridge.

> The East Bridge has so far been in the clear, although on 16 May 2001, the bridge was closed for 10 minutes as the Cambodian 27,000-ton bulk carrier Bella was heading straight for one of the anchorage structures. The ship was deflected by a swift response from the navy.

In Danish [2], but it looks like there's someone always monitoring the sea traffic, and able to close the bridge at very short notice — I assume with the red flashing lights which are used to close motorways in emergencies.

> The eastern end through the Great Belt is international water, and therefore even the largest ships must be able to sail under the bridge. The 254 meter high pylons are therefore dimensioned so that they should be able to withstand the approach of tankers of 250,000 tonnes dead weight (DWT) at a speed of 10 knots. Artificial islands protect the anchor blocks as well as the three outermost piers on the Zealand side and the two outermost ones on the Sprogø side.

[1] https://en.wikipedia.org/wiki/Great_Belt_Bridge

[2] https://web.archive.org/web/20090116051425/http://ing.dk/art...

Öresundsbron is claimed to be designed to be resistant against ships hitting it. They have placed artificial underwater reefs around the pylons. The pylons themselves can also take quite a beating.

The twin towers were designed to take a hit from an airliner and survive[0]. Sometimes even the best design fails when reality crashes into it.

[0] They expected fuel leaking to cause a devastating fire, but not that the fire would weaken the structure enough to cause the cascade failure that brought the towers down. https://archive.seattletimes.com/archive/?date=19930227&slug...

They survived for roughly an hour after the airliners hit. That hour let roughly 40,000 people make it out.

The towers failed, in the end, but withstanding the initial hit mattered a lot.

That's great, but the topic is engineering things to survive serious damage, period. Not just long enough for people to escape before it succumbs. A failed structure is still a failed structure with all the socioeconomic trouble that entails.

You're mixing up two different things.

If the design requirement for the twin towers was "be fire resistant enough to let most people out of the building", then I'd say they met that requirement, right?

If the design requirement for a bridge is "continue operating at normal capacity", then that is a very different requirement.

"Failed" isn't the binary you're trying to make it.

Yes, the towers failed to survive serious damage. But the 40,000 more deaths would have been "socioeconomic trouble", in spades. Even by your own chosen measure, the survival for an hour was a partial success.

Sure, precautions might not work as well as intended.

But my comment was in regards to having to build a really expensive bridge to make it crash resistant. I pointed out that you can instead build a cheap flimsy bridge and put the protection in the water around the pylons.

My impression is that the Baltimore bridge had no such extra protection (?) In that case, it's not really "the best design", right?

Hobart learned its lesson. You can't drive over the bridge when heavy ships sail under it.

I fell down reading about all the ships that have hit bridges, and this is probably the most practical solution for a lot of scenarios.

Yes, but Hobart is tiny so this rarely happens and relatively few people are impacted when it does.

Seems like a fair few people are going to be impacted permanently in Baltimore because of this.

"Permanently" what? the harbor will be cleared, probably sooner than later, and there will be a new bridge/tunnel built in a few years. Like that's not permanent.

The deceased and their community.

Wikipedia is missing the iconic photo of the two cars hanging over the edge of the Tasman bridge.

> "the only thing that stopped the car from tipping over the edge was the casing of the automatic transmission, which grinded and gripped into the surface of the bridge."

https://www.carsguide.com.au/oversteer/this-hq-monaros-auto-...

This situation is terrible, but to your specific question:

Anyone can build a bridge, but it takes an engineer to barely make it stand.

I like this quote. We have a medieval bridge near to our house (1000 years old perhaps), it's incredibly solidly built, but could you call it well-engineered?

It's a subtle distinction that I don't think many in the digital realm quite grasp either i.e. far too many over-engineered technical solutions for features and products that aren't even desired

"but could you call it well-engineered"

If it is still standing after 1000 years, I would say yes. You cannot build a bridge out of stones with bad engineering - it would collapse under its own weight.

edit: does "well engineered" now means over engineered to some?

"If it is still standing after 1000 years, I would say yes" but what if they included far more material in areas where it wasn't needed, skimped on other areas and it fell down tomorrow? It's almost a philosophical question, and it's true that the bridge builders happened across a solid design by accident.

But I think the true definition of engineering has to encompass a level of efficiency through design, calculation and rationalization. In other words, echoing what the original commenter said, including only what is barely necessary.

"and it's true that the bridge builders happened across a solid design by accident"

Or by experience and learning from other sucessful bridges? Stone bridges were not new in the year 1000.

There is a roman bridge that was allmost completely surviving all this time, till it was blown up in WW2:

https://en.m.wikipedia.org/wiki/Ponte_Pietra_(Verona)

If they wanted a cheap solution, they would have used wood. But wood does not last a 1000 years.

Personally I salute anyone, who can build something that lasts that long.

"including only what is barely necessary."

And "barely necessary" in solid engineering includes lots of safety margins. Not barely standing.

And yes, that includes not using more than you need, because the more material you use, the heavier your bridge is -> the greater are the forces on the structure itself even with no one passing over it.

There are some fun games out there on various plattforms, google "bridge builder"

Not a scientific simulation of course, but they do show the concept.

> But I think the true definition of engineering has to encompass a level of efficiency through design, calculation and rationalization.

The 1000 year medieval bridge we're talking about could have been an efficient design for its time.

When you'd be expected to stand under it while the local army/militia marched over it, incentives tended to align quite handily.

> only what is barely necessary.

But then one must make clear: necessary for what.

> and it's true that the bridge builders happened across a solid design by accident.

I think there is a great overlap between "holds for whatever scheme the prefecture will do to test it while I stand under" and "holds for a thousand years".

There is like a limit where fatigue stress stops being a thing in a cycle graph. Many failure modes is due to penny wise cost cutting.

I like to tell people that all engineering is about tradeoffs.

People who engineered bridges during Roman Empire had different tradeoffs to consider than people who were building bridges in 20th century.

Standing for a thousand years is rarely an ultimate goal when engineering a bridge although it is possible that Romans planned for longer timescales than us.

If we decided to build like Romans did, there would likely be very little infrastructure and many structures would simply be impossible to construct.

"If we decided to build like Romans did, there would likely be very little infrastructure"

Why? The romans build lots of infrastructure. Roads, sewage, irrigation, .. and they used the materials and technics of their time.

Can't we really do better today, with all our advanced technology?

Or can't we, because everything has to be cheap, cheap, cheap?

I mean, the romans used slaves. That is cheap. But we have machines.

How much population did the Romans build for? How much weight were the Romans subjecting their structures to, and at what acceleration/deceleration?

Do you know the movements of the supply and demand curves of the materials required since Roman times?

These types of hypotheticals are a waste of time, and only serve to illustrate hubris, as if something as complicated as comparing Roman construction and resources to modern day construction and resources could be possible.

"as if something as complicated as comparing Roman construction and resources to modern day construction and resources could be possible."

Well, one can compare the results.

Personally I like things that are build solid and can last a 1000 years.

But I don't think I said the romans build better. They just had a different intention: long lasting.

> Can't we really do better today, with all our advanced technology?

You implied a whole host of things with this statement, and considering the topic of this thread, also ramming a Roman bridge with a fully loaded modern day cargo ship.

The point is there are so many moving parameters, it is nonsensical to take 1 result of 1 technique from 1 point of time and use that as a basis for what one can expect at other points in time.

Erm, that was just directed at this point, which I quoted:

"If we decided to build like Romans did, there would likely be very little infrastructure"

The bridge has lasted a thousand years because nobody is driving 18-wheelers over it. It has nothing to do with the intentions of the builder.

"It has nothing to do with the intentions of the builder"

Why not? They did not have the intention to make the bridge resistant to such heavy loads, as that was not a use case at that time.

They had the intention to make a bridge to last as long as possible for the traffic at their time. And they surely succeded with this.

Now whether they also could have made a bridge that resists 18 wheelers for 1000 years, well, I don't know.

This is survivorship bias in action. They intended to build a bridge. That is all we can infer from the fact that a bridge exists. That they used available materials and the bridge was not abused by subsequent usage outside its design spec is not proof of any specific intention on the part of the builder. That exists only in your head. It's like assuming dinosaurs died in specific spots with the intent that their bones petrify and fossilize. You're reading too much into not enough facts.

Maybe, but lots of roman buildings endured the time in much better shape, than many buildings that were build after them. Have you seen some of them in front of you? I have and I am impressed. (I am in italy right now to go look at some more).

Also we know a bit more about the romans than just their bridges.

You can't use Roman techniques to build a bridge over a river that's a couple of kilometers wide that can carry heavy trucks, unless you're thinking of building a dam.

It is the same type of person that says Romans were more ecological because we have cars and they had carriages drawn by hand or by horse.

Which is to say "let's just pretend that all of those pesky details do not exist".

This is an excellent point, the tradeoffs are specific to the time, place and needs of the builders

> could you call it well-engineered?

What is well engineered depends on the goals and the limitations of the state of the art at the time. I would say that a thousand year old bridge might count as well engineered if the goal was a bridge that had a low total lifetime cost.

Why are you throwing shade at civil structural engineering?

Do all bridges we build need to be able to withstand the force of an entire shipping container bridge hitting it at high speed? What planet should an engineer think that a shipping container has managed to veer off course so badly that they hit a bridge at full speed, fully loaded? That is a sad and significant outlier event.

This is a common joke in engineering.

It’s not meant to be an insult, but a compliment noting that engineers know what the essential parts of the bridge are

I suspected it might be but I couldn't tell from the post. There is a lot of self deprecating humor amongst engineers / engineering programs.

I would guess none. No bridge span could survive complete loss of it's supporting abutment. Some bridges are engineered to survive partial loss. For example if the left side goes the right side will hold it up. But from the video the ship looks like it took out the entire supporting structure.

Why would slumping or buckling but not-quite-collapsing be a functionally better outcome than complete failure? In both cases, the sheer size of the physical changes is going to lead to forces that humans won't survive, so there's no benefit there. In both cases, the bridge is going to have to be completely demolished before rebuilding, so there's no benefit there.

A bridge that could stand the loss of a single support pier without any significant collapse would obviously be preferable -- but that's a big ask. I'm not a structural engineer, but I am aware of scaling laws [1] and it feels to me that those scaling laws are going to mean that increasing the margin of safety by x is going to increase costs by x^n. For a project like this one, where cost was apparently the deciding factor over a tunnel, that matters.

[1] https://galileo.phys.virginia.edu/classes/609.ral5q.fall04/L...

>Why would slumping or buckling but not-quite-collapsing be a functionally better outcome than complete failure?

Well for starters, there's a better chance of less (or ideally no) people forced to get their feet wet and go missing or die from drowning or hypothermia.

The specific point I'm making (in the sentence following the one you quoted) is that no, there is not a better chance of those things. If a bridge of this size is going to fail in any significant way, it is going to lead to loss of life.

The broader point is that attempts to blame the bridge designers here are misplaced. It really isn't reasonable to have hoped that they could design a structure that could cope with this kind of failure, within the cost constraints that they had. And cost constraints were a real thing for the designers of this particular bridge.

You could try to avoid collisions with barriers, or make the bridge fail differently (only a few spans), or make it tolerant to a single support failing. But you need a pretty beefy steel beam to survive a direct hit by... Uh... 200,000t(??) traveling even at a slow jogging pace. (And then it transfers the energy into the rest of the bridge, which will very much not like it).

I guess we can be happy failure like this is rare, and that the bridge was not busy: reports indicate 13 cars, and about 7 persons still missing. This could be so much worse.

The best way to think about measures is after we know the full chain of events that have lead to this.

Some other bridges have barriers around, but not connecting to the pylons.

Those are great for little boats like one of those superyachts. They become dominoes that hit before a boat like this: https://www.vesselfinder.com/?imo=9697428

Absolutely. 116851 long tons deadweight, which the Google info box says includes everything (busy now, so can't check in detail). That's 120,000,000 kg, so a little bit less than I guessed. Now looking at 10km/h or 6.2mi/h or 2.78m/s, that's enough to come up with a big E for E = 1/2 * m * v². The momentum p = m * v is also rather unpleasant. If the momentum was suddenly transferred into my 2,000 kg car (e.g. if the ship hit my car), I could do my work trip in about 1s, though that's only a few times times faster than the ISS (which travels at 7660 m/s).

[I'm very busy, so hopefully I didn't forget/add a few 0s by accident. Anyone feel free to correct me if I did.]

Right. I am not really thinking of designing pillars that are impossible to knock over. I am thinking of alternative bridge designs where a higher percentage of the total bridge stays up when one pillar is taken out.

On this bridge, the main section of the bridge is supported by four spaced pillars, making three main spans there. One of the middle two towers was hit, so this should affect two of the three spans. But it took down all three of them. A span that was supported on both sides by intact towers still came down. That is what I find most surprising here.

Most bridges nowadays (say last century) depend on a careful balance of forces that are transferred through a chain of members in tension and compression.

When any piece in the chain of those forces breaks, the entire structure loses ability to transfer forces and breaks.

This arrangement is what allows us to build these structures in the first place. There is careful calculations of forces and risks and allowance for margin for error and unexpected events. But, unfortunately, in many cases those do not include ramming things with a large container ship...

Thanks! So why are huge—ass container ships allowed to navigate underneath fragile public bridges with single points of failure? The not unlikely worst case is that the ship is out of control for some reason…

We notice these type of accidents because they’re so rare. 5k+ people die each year because of large trucks on the road, by comparison, boats and bridges are very safe — that’s why it’s allowed.

Because bridges over harbors are quite common an incidents like this are rare.

The Dutch ports of both Amsterdam and Rotterdam have no bridges at all. It's all tunnels. I think that's the best way to go; the least chance of conflict between road and water traffic.

Often in America the government waits for something to fail miserably before engaging in a high effort high cost activity that requires a lot of coordination and public buy-in.

Wow.

Random ship hits a bridge.

Shakes fist at sky "the government".

But that's what you do with random events -- create policies to prevent them from happening, lowering the incidence rate and minimizing damage once it occurs. Which is exactly what government and laws are all about.

That is a generous reading of the parent comment.

It sounded much more like a common trope, "the do-nothing government just lets things fail, doesn't take action until something fails".

The amount of arm chair quarterbacking here is astounding. Reddit has a more nuanced conversation than HN right now.

A bridge got hit by a container ship at speed and folks here are talking about this like the bridge was not up to standard, or why there was a bridge there at all when they know nothing about the locale. I am not a structural engineer, but I am going to go ahead and guess that not much would still be standing from a direct hit from a container ship. And from observation bridges like this exist all over the world and don’t regularly get struck by container ships.

It was a freak accident.

If we want to point fingers or question things, perhaps if anything the question is why the container ship lost power repeatedly? Was this a known issue before leaving port?

> A bridge got hit by a container ship at speed and folks here are talking about this like the bridge was not up to standard, or why there was a bridge there at all when they know nothing about the locale.

You're right, I don't. But I do know there are other locales where they seem to explicitly avoid bridges crossing heavy ocean traffic.

German Wikipedia has an article on ship deflectors. What is says there is that ship collisions were viewed an an inevitable hazard until the 1980 collapse of the Sunshine Skyway Bridge in Tampa. That was 45 years ago.

Trying to search for "ship deflectors" or whatever just brings up pages and pages of Star Wars shields and such in English.

I know they exist, and perhaps after this they'll exist a bit more.

Tunnels can have other issues: https://en.m.wikipedia.org/wiki/Category:Tunnel_fires and given American drivers I think I’ll take my chances with the big old boats.

All roads should be underground! What if a plane crashes into a surface road? Or a meteor? Somebody think of the children!

After making all roads underground: "Tunnel collapses are killing all our children! Let's make all roads above ground!"

Not unlikely? Can you point us to all the other times this has happened? You must know of several given your knowledge of how obviously likely this is.

It's not especially common, but the Sunshine Skyway Bridge in Tampa Bay is a famous example. Similar circumstances - it collapsed after being hit by a ship.

The replacement bridge in Tampa famously added "dolphins" which are bumpers in the water to protect the bridge pylons.

that collapsed almost 40 years ago, which really emphasizes it's flat out uncommon, no "buts" needed.

Downvoted for unkindness towards internet stranger.

When has "nothing will happen as long as we can carefully navigate our massive vessels around these critical pillars" ever been a trustable safety measure? Over the long term shit like this will happen if it the possibility that it happens is not excluded by other measures.

This is a public bridge 5 years in the making and who knows how long in planning, and people have been extremely lucky that it collapsed at 3am and not in the middle of the day. It doesn't matter at all how unlikely this is in a given time frame if the impact if it happens at any point in time is catastrophic.

Because the Port of Baltimore is a very major port, and not allowing ships under it really isn't an option.

Vertical clearance for ship traffic might have been the reason this kind of bridge was built in the first place. Otherwise, something lower and more causeway-like might have been sufficient.

If it's a very major port, they can afford to make it a tunnel.

There already are two tunnels for I-95 and I-895 under the port.

Then why is this one a bridge? Why not go all the way and make this a tunnel too?

Mostly to have a hazmat route around the city (HAZMAT trucks aren’t allowed in the tunnels) and because bridges are cheaper than tunnels. They needed a third crossing because the traffic warranted it.

> Mostly to have a hazmat route around the city (HAZMAT trucks aren’t allowed in the tunnels)

That is a very interesting point I hadn't considered at all. Price is an obvious point, but I hadn't considered hazmat.

It does make me wonder how hazmat traffic is handled around Amsterdam. I think they are allowed in some tunnels here.

Most highway tunnels (including the Coentunnel and Zeeburgertunnel on the A10 ring road around Amsterdam) are category C tunnels, which means some hazmat allowed depending on the nature of the materials, the quality of the containment, and the volume transported. Notable exceptions are the Schipholtunnel (category A, fewer restrictions) near the airport and the Arenatunnel (category E, severely restricted) under the stadium.

HAZMAT can go the other way around the city on 695. My understanding is that the main issue was cost.

> Bids for construction of the proposed Outer Harbor Tunnel were opened in July 1970, but price proposals were substantially higher than the engineering estimates.[11] Officials drafted alternative plans, including a four-lane bridge, which was approved by the General Assembly in April 1971.[12][13]

https://en.wikipedia.org/wiki/Francis_Scott_Key_Bridge_(Balt...

Why does anyone use fragile asphalt (20 years) for busy roads when engineered concrete lasts 50 or more? Because the better option costs more.

This was a big point of contention when a local town announced it was replacing the failing asphalt on the section with the most traffic with slabs of concrete. [0] People complained about the price. Meanwhile, over a decade on, nearby asphalt laid with the same renewal project is already cracking while the busy main thoroughfare remains undisrupted by road work.

It's hard to persuade people that long-term investment is worthwhile.

[0] PDF page 10 (print 17): https://www.dot.ga.gov/PartnerSmart/Public/Documents/publica...

The tunnel and the bridge run parallel. Tunnels are not suitable for all types of traffic.

However hazardous cargo is not allowed in tunnels so bridges like this one are the only way hazmat can be transported over water crossings.

On the news this morning a commentator made it sound like that rule was imposed after 9/11.

It makes sense to me that cargo would be restricted, and it's bizarre that it would be related to terrorism (an additional rule isn't going to prevent an attack...).

It's still a sensible rule. As we see with this incident rare events do happen.

Tunnels are far more expensive - the 1.5 mile 4 lane Fort McHenry tunnel was like $750M vs. $140M for the 1.6 mile 4 lane Key bridge, although adjusted for inflation that’s probably more like $750M vs $320M.

The underlying problem here is that automobiles are inherently inefficient so you either get epic traffic jams or have to massively overbuild capacity, forcing the engineers to deliver as many lanes as they can for the budget.

How expensive is this accident to the city? Likely billions, right?

Your point is correct: if they knew the accident was going to happen today, they might have changed their behavior.

Unfortunately, nobody who knew it would happen today warned anybody.

Yes, but there’s a difference between what people will pay in advance to prevent one of many low probability catastrophic failures and what they’ll think was worthwhile for someone else to have paid to prevent the one which actually happened.

Those calculations are really hard: say they had built a tunnel, what are the odds of the same number of people dying in a fire after someone crashes into another car? Would we have needed to spend any money at all if more people had used railroad alternatives to driving and such an expensive bridge or tunnel was not justified on traffic grounds?

This works fine until there's a story of issues with a tunnel, then we say we should have built a bridge.

The Patapsco is much wider here than at the locations of the two tunnels. It would have been a much bigger and more expensive project to build a tunnel that long.

In addition to the Hazmat issue mentioned below, tunnels have a bad record when fires break out inside them. E.g. the Kaprun disaster [0] which killed 150 people, and the Gotthard Road Tunnel [1] fire, after which the use of large vehicles was constrained.

[0] https://en.wikipedia.org/wiki/Kaprun_disaster

[1] https://en.wikipedia.org/wiki/Gotthard_Road_Tunnel#2001_coll...

Vertical Clearance for bridges around ports is the method used around the world. Of course, also tunnels. But building tall bridges for access is very common.

>>Because the Port of Baltimore is a very major port, and not allowing ships under it really isn't an option.

It is now a very large port that is completely closed off from the sea.

And two sides of the city no longer linked

The damage from this accident is only beginning.

Even if loss of control of a large container ship was considered in the design of the city, port, and that particular bridge, ships were not even close to the order of magnitude of mass of today's ships.

And, it lost power at almost exactly the worst moment. What are the odds?

> And, it lost power at almost exactly the worst moment. What are the odds?

I don't know, but I suspect we don't hear much about all the times power is lost at moments that are less than the worst.

EXACTLY!! If it happens often, and they just restart because it's no big deal in the ocean, we wouldn't hear about it.

Of course, it seems that a high(er) frequency of failures should be taken into account for zones where it is critical, such as in port. I just saw a few days ago that a ship docking took out a couple of cargo cranes (sadly, badly injuring a crane operator); didn't seem like a power outage, more of a misjudged steering.

>And two sides of the city no longer linked

Have you looked at a map of Baltimore? They're very much linked, you just have to drive a little farther. The only issue will be that all the traffic this bridge previously carried now has to reroute to the bridge farther north, so now traffic will be much heavier.

Yes, of course; I made the comment after looking at a map.

The direct or short link is now broken. Everyone must now go around the entire harbor, on roads that will now have 40k more cars every day, instead of directly across it. I wasn't saying that some area was a disconnected island, but that many trips will become more costly or non-viable for years until the bridge is rebuilt.

Perhaps I should have said "no longer directly linked", but thanks for the picked nit.

It's not a nit-pick, you said "no longer linked". They are absolutely linked, you just have to drive around a few more kilometers. You said nothing about the traffic load, you wrote that it was absolutely impossible to cross! ("no longer linked")

Perhaps English is not your first language, or you are not recognizing the difference between casual conversation and formal scientific papers.

This is casual conversation. Writing quickly and colloquially, with the assumption that "no longer directly linked" or "no longer linked as they were 10min before" is inferred, certainly to anyone who has seen a map of the area. It should also be inferred from the sentence alone, as if the link had been to an island, then most writers would have made the much stronger point, saying "completely cutoff from the mainland" instead of the much weaker "no longer linked" (just because one link is broken does not imply that there are no others).

If you want to comment that "I was confused by your meaning and it could have been more clear if you said X" is a perfectly fair statement.

But deliberately taking absolutist definitions in a casual conversation where meanings can be implied / inferred, is an unfriendly, oppositional, if not hostile stance.

In any case, I apologize if you were offended that I didn't include all the qualifiers and assumed they would be apparent to the reader. Have a nice day.

English is my first language, but you obviously speak it much worse than most ESL people I know. I even used to live close to Baltimore, so I know the area. You said "no longer linked", not "no longer directly linked". There's a world of difference, and now you're trying to paint your comment as something it was not.

Yes, I've already acknowledged the ambiguity in the original sentence, and I apologize again to you for any confusion it caused you.

However, please learn that ambiguity in informal speech/writing is substantially different from errors in formal edited speech/writing, and different responses are appropriate.

In the context of formal writing (e.g., an academic or industry paper, book, etc.) we should expect almost all ambiguity to be edited out, and not allow for inferences in either direction; i.e., your complaint would be valid.

However, in casual speech/writing (e.g., SMS, social media comments, non-formal emails, etc.) it is common and not serious to leave IMPLIED components in the conversation. It is certainly acceptable to ask for clarification such as "did you mean to imply that some area was made entirely inaccessible by that event?". But it is inappropriate to accuse someone of being dead wrong by leaving out the implication.

The request for clarification should result in the speaker/writer saying "ya, I did mean to imply XYZ, not PDQ, thx for pointing that out." — mutually and efficiently finding the truth. The accusation, especially continued insistence on the accusation being the one true correct way, is the way to start an argument trying to establish dominance.

It might also be worth noting that your class of people — those familiar with the Baltimore area — should have been MOST able to recognize that "not directly" was the inferred meaning, since you know it's not linking an island to the mainland. That you chose the hostile "j'accuse — you are wrong!" form of discussion rather than the collaborative friendly "btw, you did not mean to imply that the bridge linked to an island" (and continued to insist on the hostile approach) tells us all that this is more about your emotional state and/or approach to human interactions than about the ambiguity itself.

Have a great week

If bridges and container ships indeed do not go together (something I don't necessarily agree with), you probably want to take away the public bridge and continue to let ships go by. This is economically speaking for the area. Car traffic is just not very efficient in the comparison between the two.

Edit: of course there are a ton of other solutions here as well. I am disagreeing with the parent that it is the cars which should get to stay and the container ships which have to move.

You can have smaller container ships. Or have the port outside the bridge. Or indeed replace the bridge with a tunnel, or a better bridge.

Amsterdam has no bridges at all crossing the IJ on the west side (where sea-going ships come from) and only a single bridge on the east side (though there's often talk of adding another). Everything is tunnels.

Rotterdam has bridges (including the famous Erasmusbrug), but only east of the port area. To the west, everything is tunnels. And the largest ships don't even come close to the city center, but dock at the Maasvlakte out at sea.

For both cities, ports have constantly moved closer to the sea.

You don't even need to run it as a tunnel the entire way through - Chesapeake Bay has vehicular traffic routed through a combination bridge/tunnel, using tunnels to span the two major shipping channels crossed by the complex.

The A10 ring in Amsterdam does the same on the east side. The west is all tunnel, the east is half tunnel half bridge.

Baltimore has been in a steady state of decline as long as I can recall. Industry has constantly moved away.

https://foxbaltimore.com/news/local/as-residents-leave-balti...

>“There’s a lot of people staying [in those cities] and we want to be sure they’re not left with an excess of infrastructure that’s impossible to maintain,” he said. “So what do we do about it?”

Don't know why this is controversial.

I lived in the NOVA area for more than a decade and each visit to Baltimore (every few years) was more depressing. Of course, that's anecdotal but I'll stand by it.

Maybe they felt it was off-topic? Industry has been moving away since the 1950s. Today I read that container traffic has increased over the past couple of years.

It is hard not to feel a sense of tragedy if you know something about the place. It is written all over the city. The blocks and blocks of boarded up row houses speak for themselves. Now they are tearing them down. Maybe that is for the best, but it doesn't seem like a win.

I get the same impressions.

> out of control for some reason...

I think the whole ship went dark for a moment. That may have had an impact on the rudder, and then some strong current and/or wind, pushing it sideways.

Couldn't see tug-boats.

Was watching CNN around 6AM EDT, they had a reporter on scene who mentioned wind "whipping across" the harbor. This was in reference to the potential survivability of the freezing cold water, but it seems likely it could have been a factor in pushing the ship off course as well.

To be able to reach the port. You could argue that such bridges shouldn’t be built in front of ports, but the public also doesn’t like having to drive long detours, and the likelihood of an incident like this one is very low.

It is worth observing that this bridge seems to have 2 pylons and one of them collapsed. The failure seems comprehensible after that - you can see in the video how the balances came apart, there is nothing to hold the left side up so it falls and then remainder of the bridge tried to rotate around the remaining pylon and failed.

It's no surprise that the entire bridge collapses after a pylon collapses. What surprises me is that the pylon collapses. I'd expect those to be extremely solid, with tons of padding. But with ships getting bigger and bigger, I guess there's a limit to what you can account for.

Ships are hundreds of thousands of tons in weight and the momentum acts as a force multiplier. Plus it hit the pylon dead center, which is the worst case scenario. It’s not terribly surprising.

I think there’s also an underlying expectation that any competent ship captain would at least be able to see that they’re on a collision course with the pylon well ahead of time and be able to compensate. Which obviously didn’t happen in this case.

There is another video where we can see two power outage occurred. Ship was uncontrollable but with enormous amount of inertia.

I'm sure captain tried to do anything he can to avoid collision.

The trajectory of the ship seemed near perfect right up until just before the bridge where I suspect it experience it's mechanical issue.

Interestingly, a surprising number of ship-ship collisions occur due to an unnecessary last minute evasive-action manoeuvre between ships that weren't actually on a collision course in the first place. There's a whole section devoted to this in the outstanding book 'Normal Accidents' by Charles Perrow.

Case of, they are built strong, but not that strong.

A container ship has huge inertia, I don't think any bridge could be built to take a direct hit like that.

Container ships of yesteryear are also many times smaller than modern ships.

On a long enough timeline we all get rammed by a container ship.

I would be interested to know some calculations with factors like: expected bridge lifetime, chance of being rammed per year, cost of making supports strong enough plus an extra safety margin to survive maximum ramming force, cost of having major commercial shipping route unusable for an extended period.

Bridges only last for roughly 50 years. Considering such collisions are rare enough to make the news as a memorable event you can workout for yourself that the odds are quite low over a bridges lifespan.

They are designed to withstand smaller boat impacts because they occur relatively frequently, but cost vs benefit on rare events that are difficult to mitigate is quite different.

Do you mean 50 years without maintenance? I would be shocked if major bridges weren't designed to last indefinitely.

Nothing lasts indefinitely...

I can think of at least 5 famous bridges that are way older than 50 years...

Sure, and there's 100's of thousands of replaced bridges that don't immediately spring to mind.

Though to be clear designed to last 50 years isn't the same as saying it will only last exactly 50 years, or that theirs nothing you can do to extend a bridges lifespan if it's replacement is running a little late.

If it is a famous bridge, it seems possible that they’ve done some special extra maintenance, replace more wear-and-tear bits that would normally fail. Eventually you probably get the tourist attraction of Theseus.

Depends on the bridge. Steel and concrete bridges can last for at least 100 years. But it depends on the environment, its expected use, the construction, design. Some famous major bridges failed early due to poor design or poor construction, but many still fail due to lack of maintenance.

The average age of a bridge in the USA is 43 years. But we also have an epidemic of unmaintained bridges.

No bridge made today is designed to last indefinitely. Many different forces will degrade the bridge over time, even with maintenance. Steel stresses weaken it over time. Concrete weathers over time due to salt, chemicals, water, wind, and the steel reinforcements tend to corrode eventually.

Stone bridges may last for an exceptionally long time, but their weight and expense makes them only useful in limited applications, typically as small rail overpasses. Ones that were designed for horse and buggy end up slowly failing as heavier trucks and cars in traffic weaken them.

The same fate lies for timber bridges. When well maintained they can last for 75 years, but it's expensive and requires certain skills. They were also mostly designed before heavier cars and trucks, and for less traffic. Most famous covered bridges today are being closed to traffic due to increased wear.

According to https://www.fhwa.dot.gov/bridge/, the federal government oversees more than 610,000 bridges in the USA. There are a lot of unmaintained small bridges. But I'd hope that the major ones get more attention.

Here's a list of major bridges that need attention (& aren't getting it): https://artbabridgereport.org/state/ranking/top-bridges

FHWA provides up to $7 Billion in assistance in maintaining bridges. But it would take at least $125 Billion to begin dealing with the structurally deficient bridges in the USA, according to the ASCE Infrastructure Report Card[1].

Add to this the fact that many bridges in the US are privately owned, and it's the responsibility of the bridge owner to maintain them. But guess what's not profitable for a private enterprise? Maintaining bridges. Despite this, train derailments and property damage continue every year due to unmaintained bridge and train infrastructure.

The executive has proposed funding for repairs, but as usual, it's not enough[2]. So far they've gotten almost half that number of bridges repaired, and pledged another $300M,[3] which is still just a drop in the bucket of what's needed of the backlog; it doesn't address all the new maintenance that will be needed each year.

According to the American Road & Transportation Builders Association, there are 167 million crossings on 42,400 bridges rated in poor condition. [4]

[1] https://infrastructurereportcard.org/cat-item/bridges-infras... [2] https://www.nbcnews.com/news/us-news/biden-has-plan-fix-amer... [3] https://www.whitehouse.gov/briefing-room/statements-releases... [4] https://artbabridgereport.org/congressional/map

Personally I'm in favour of government maintaining stuff, but https://en.m.wikipedia.org/wiki/City_Bridge_Foundation has maintained most of London's bridges privately for nearly three quarters of a millennia so I wouldn't say it can't be done.

I'm not saying it can't be done, I'm saying we specifically fail to hold private industry accountable in the US. So we get things like poisonous runoff from agriculture and industrial production, insanely slow and outdated train lines, privately owned bridges that fail and cause injury, property damage and traffic jams, massive wildfires causing property damage and loss of life from unmaintained utility infrastructure, and worldwide banking crises, among other things.

Is it impossible for these things to stop happening? No, not at all. But it's probably not going to stop, in this country, because we let private industry get away with whatever they want. If this were the UK the story would be very different.

Fair. I can't claim to know how to make it work better in the US. We have also other private infrastructure in the UK that's not working so well (like the water companies, which are not providing enough sewage processing capacity and so allow the extra to overflow into rivers)

I mainly made that comment because it still blows my mind the the City Bridge Foundation has been going for 740 years

Interested in this claim, because it sounds about right, except that I can’t name a bridge constructed in the past 50 years.

The bridges we can all name are pushing 100+ right?

New York City has had two major recent new bridge replacements that probably about 20M people can name: the Mario Cuomo (formerly Tappan Zee) and the Kosciuszko bridge.

I’d argue the Bayonne Bridge raising kinda counts since it was almost a rebuild and more impressive in many ways since it stayed open the whole time.

Meanwhile in the San Francisco Bay Area they replaced the Bay Bridge…

The Tappan Zee bridge certainly wasn't built with the intention of replacing it after 65 years. Nor, fortunately, was the George Washington bridge.

Agreed I was just addressing the parent poster question of whether anyone can name a major bridge built in the last fifty years…

> Started on the cheap during the Korean War, the Tappan Zee was deliberately built to last just 50 years.

https://www.nytimes.com/2006/01/17/nyregion/a-bridge-that-ha...

I can't argue with that!

The old Tappan Zee was basically a perfect encapsulation of "dumb midcentury infrastructure decisions."

1. Built to last only 50 years to save on materials (as the other commenter noted).

2. Built over literally the widest possible part of the Hudson because the governor got in a pissing contest with the Port Authority and wanted all the tolls to go to the state, which wouldn't have been the case had it been built like 2 miles south where the river is narrower.

3. Designed with zero redundancy, such that a "critical fracture could make the bridge fail completely because its supports couldn’t transfer the structure’s load to other supports." [0]

So yeah if we're being real, 50 years was quite optimistic.

The new Tappan Zee is apparently supposed to last 100 years, though given the incidents with substandard materials being used, as well as ever-increasing traffic, who knows.

That said, driving over a bridge 10 years past its planned EOL and being able to look down directly to the water through gaps in the concrete was always a nice feature though -- who needs coffee when you've got that to get your heart rate up!

[0]: https://en.wikipedia.org/wiki/Tappan_Zee_Bridge_(1955%E2%80%...

"dumb midcentury infrastructure decisions."

Keeping in mind that mid-century Japan and Germany were in ruins and the possibility of nuclear annihilation of urban centers very much at the top of many people minds. 50 years may have seemed an optimistic survival rate of built structures at the time.

The eastern span of the Bay Bridge, which had previously been a cantilever bridge, which was damaged during the 1989 Loma Prieta Earthquake, and shown to have quite obvious seismic deficiencies.

Its replacement is a self-anchored suspension bridge.

The original western span, actually a double suspension bridge, remains standing, as constructed in 1933, 91 years ago.

So this detail… that is where my misconception arose. Thanks!

The western span had substantial seismic remediation applied in 2000-2001.

The Francis Scott Key bridge - the subject of this story - was finished in 1977, and took about 5 years, so... much of it was constructed in the last 50 years. ???

How many bridges, such as highway overpasses, that you use regularly can you name?

Here's an interesting list of major bridges with dates, most of the newer ones being replacements: https://www.carolinadesigns.com/obx-guide/fun-info/bridges/

They even note a rare exception designed to last 100 years with maintenance.

Mackinac Bridge is somewhat famous, built in the 1950s.

They more or less do continuous maintenance during the warmer months of the year.

(So older than 50, but younger than 100)

Michiganders will also know the "Z Bridge", completed in 1988

https://en.wikipedia.org/wiki/Zilwaukee_Bridge

Sticking with the mid-western therme, the Chicago Skyway was built in 1958

First span of the Blue Water Bridge (Port Huron to Sarnia) built 1938, doing just fine as far as I know. (Drove over it a couple of weekends ago.) Second span was 1997.

The Crimean bridge is quite (in)famous, and it was built quite recently.

The Millau Viaduct also comes to mind when thinking of famous, iconic modern bridges.

The Øresund Bridge as well (opened in 2000).

Most of the bridges I can think of in the state of Washington are much newer than that.

There are now two Tacoma Narrows Bridges. The oldest was built in 1950. The one that infamously collapsed was built in 1940. The newer bridge is from 2007. The West Seattle Bridge was closed due to damage in 2020 and reopened after repairs in 2022. It was originally built in the 1980’s after the previous bridge was hit by a ship. There are two floating bridges on I-90 east of Seattle. One of them sunk during reconstruction work in 1990 and was replaced. Theres also a new 520 floating bridge that opened in 2016. The Hood Canal Bridge (also a floating bridge) originally opened in 1961, sunk in 1979, was reopened in the 1980’s, and large parts of it were replaced in the 00’s.

The Ballard Bridge actually is over a century old! It was opened in 1917. However there was a lot of reconstruction done during the 1930’s. The Fremont Bridge is also from 1917. Both of these bridges span a ship canal that was built between 1911 and 1934. The Aurora Bridge was also built in the 1930’s.

I can't imagine how it is to be so insulated from the world to not be able to name a single major bridge construction in the past 50 years.

If you don’t live somewhere with famous/major bridges it’s really easy. I doubt I could name ten bridges period that aren’t in my mid-sized city (and I can only give the correct name for two of the ones here, neither of which is famous). I can only identify maybe four by sight from outside my city—I can name a few that I couldn’t pick out of a lineup of photos.

vincent thomas bridge in LA is from 1960 -- old but not 100+

There's a massive one being constructed right now - the Gordie Howe International Bridge. It'll be the second bridge (and fourth crossing) between Detroit and Windsor when it opens next year. Although maybe I only know of that one because I grew up in metro Detroit.

Depends on the "we" you're talking about, I guess.

In the DC/MD/VA area, almost all the bridges I can name are less than 100 years old. Woodrow Wilson, American Legion, Chesapeake Bay Bridge, Chesapeake Bay Bridge-Tunnel, Key Bridge, Key Bridge, Nice Bridge, Memorial Bridge, Chain Bridge, 14th street bridges... Some of those were even built after 2000! Also the New River Gorge Bridge in WV is pretty famous and not even 50.

Well, actually, the Key Bridge (in DC) apparently turned 100 years old last year. And I guess the Long Bridge (though not a road bridge) is also over 100...

Living not too far outside Minneapolis, we rebuilt a bridge that rather famously came down a bit over 15 years ago.

https://en.wikipedia.org/wiki/I-35W_Mississippi_River_bridge

Doesn't the US have a problem with bridges exceeding their expected service lives?

The boom of bridges after automobiles became common are all running out of time. Yet, paying for a replacement early is also wasteful.

So it's an issue, but those bridges where also constructed by a far poorer nation so it's not that big a deal.

> but those bridges where also constructed by a far poorer nation

That's a must more interesting question when discussing the topic of infrastructure.

Sure we've created a lot more money in the last 50 years, but we've also lost a lot of domestic manufacturing. When it comes to something as vital as roads and bridges are we poorer when we have less paper money or when we are less independent in the manufacturing and maintenance of them?

Money is just a proxy for power, so “poorer” means not able to do something. Note that you are referring to “we” being poorer, and a country’s ability to do (or get) something is not the same as an individual within the country’s ability to do something.

Money is a side issue people are generally a lot more productive than we where 50 years ago and the US population is 50% larger. That means the government has a lot more resources to work with though how it spends them is another question.

I think people feel poorer because income inequality increased so much. New homes are huge because new home buyers are the upper end of the wealth curve. Same deal with cars etc. Stuff that targets everyone like normal sized TV's ends up being extremely cheap because revealed preferences show people buy cheap when it's an option.

>That means the government has a lot more resources to work with though how it spends them is another question.

it's not that clear-cut. regulations regarding construction are many times more strict, as well employment restrictions and safety code.

I mean, the things like the transcontinental railroad were built with what would largely be considered inhumanely treated human slaves by today standards -- that kind of 'advantageous hiring condition' thankfully no longer exists.

Stuff like that plus millions of other regulatory nuances that drive the cost of development to be many times more expensive than during the bad old 'wild west' make these kind of value analysis gapped by many years near impossible.

The transcontinental railroad was built without modern heavy equipment. Today fewer people can get a lot more work done even with humane working conditions and modern safety code. Which helps explain humane working conditions and modern safety code.

As to regulations, in 2023 an I-95 bridge failed after a gasoline tanker truck fire. They took 12 days to get a temporary replacement that got traffic flowing again. You occasionally see such projects where we need a fix now and then it happens. However, it was a temporary replacement and they needed an actual long term solution.

The difference between such rapid projects and more typical ones include time consuming steps to preventing dirt from settling and causing problems in the future etc. Regulations are filled with such tradeoffs, but that doesn't mean we're unable to move more quickly just that we can afford to do something else.

> Money is a side issue people are generally a lot more productive than we where 50 years ago and the US population is 50% larger

Production per capita may have gone up, but that's (a) likely measuring productivity in financial terms and (b) heavily correlated with an increase in natural resource consumption, especially fossil fuels.

If we want to consider ourselves richer because we are able and willing to use more natural resources today could lead down a dark (and very hot) road.

Fossil fuel consumption in the US is down way down especially on a per person basis because of improved efficiency and cheaper alternatives. There's more Americans today, but in many ways we are consuming fewer resources while still being better off.

Compare a modern jet with one from the 1974 and sure many passengers have less leg room but it's hauling both people and 3rd party cargo while still using far less than 1/2 the fuel per passenger mile. Such improvements really add up and include things like engineered lumber using fast growth pines.

Look at the most popular car 50 years ago and you'll see the Ford Pinto. It's slow, unsafe, tiny, time consuming to maintain, fuel inefficient, and missing modern amenities but it was affordable. Inflation adjusted it's roughly the cost of a Mitsubishi Mirage which while better in just about every way is a rough equivalent the reason people are buying crossovers rather than the Mirage today is because people just have more wealth in real terms.

When you say it is "down way down", how much is that exactly?

The data I found only goes back to 1965 [1], but from the absolute peak in the 70s to today we've reduced per capita use by around 30%. Over the last 20 years we've reduced it by around 15%, going back 10 years and the reduction is only around 5%. Time scale matters a lot here, as does a definition of what "way downdowm" would mean in real % reductions.

I totally agree we've made use of oil more efficient in things like engine efficiency. We've also found more uses for oil byproducts, which can be good or bad depending on your opinion (and again, on your time scale). If we've improved fuel efficiency by 50% and at best reduced fossil fuel per capita by 30%, we've squandered some of those gains by using more oil for other things.

Whether that's a good or bad thing is really up to opinion, goals one has in mind, and how one weighs the trade offs.

[1] https://ourworldindata.org/grapher/fossil-fuels-per-capita

At this scale even 10% is a big drop, down by 1/3 is IMO down way down.

That chart gives 31% in 49 years 63,836 in 2022 vs 92,635 in 1973, but the numbers are dropping faster each year.

https://en.m.wikipedia.org/wiki/Jevons_paradox

That's a common topic here, yes, though honestly I rarely hear about a bridge collapse. I don't actually remember the last time I saw news of a bridge or overpass collapse that wasn't causes by damage like this.

Makes me want to find the data now. I don't actually known if our bridges are too old, poorly maintained and falling apart early, or if the whole topic is just herd mentality and politics.

>I don't actually remember the last time I saw news of a bridge or overpass collapse that wasn't causes by damage like this.

Fern Hollow Bridge Mk. II?

If we count pedestrian overpasses as part of overpass; FIU pedestrian overpass.

Among the more spectacular recent US bridge failures was the I-35W bridge in Minneapolis, which failed during rush hour with bumper-to-bumper traffic with a loss of 13 lives on 1 August 2007: <https://en.wikipedia.org/wiki/I-35W_Mississippi_River_bridge>

There's a list of many more failures at Wikpedia, though international in scope:

<https://en.wikipedia.org/wiki/List_of_bridge_failures>

There are a number of ship-bridge collisions listed, as well as fuel-tanker explosions, which seems to be a surprisingly common failure mode.

Also numerous failures in China, though how much of that is simply a scale effect I can't say.

> Bridges only last for roughly 50 years.

The bridge projects I've been on spec 75 or 100 years. Main difference is better protection/sacrificial depth on ferrous members.

I remember one of my engineering lecturers giving a good rule of thumb as “your retirement date, plus 10 years”

> Bridges only last for roughly 50 years.

https://en.wikipedia.org/wiki/The_Iron_Bridge

Opened in 1781, still in service and perfectly safe. Of course, there are no container ships nearby. But I reckon you could sail a container ship under it, given enough water; and to damage the bridge supports, the container ship would need climbing equipment.

1781 isn't many years after the Declaration of Independence.

Notice it's a pedestrian and not a vehicle bridge as well.

If there was enough water for the 48m beam, 24m airdraft container ship that just collapsed the Baltimore bridge to attempt to navigate under the 30m span, 16m high Iron Bridge I don't think the bridge would stand a chance...

Heh! OK, so I'm wrong about being able to sail a container ship under the Iron Bridge.

It didn't take motor traffic, because when it was built, there was no motor traffic. But the claim I replied to was about all bridges. But it used to take vehicle traffic: the WP article says "In 1934 it was designated a scheduled monument and closed to vehicular traffic."

And all bridges do last roughly 50 years. Look at all bridges and figure out the average, median, or mode lifespan is reasonably close to 50 years +/- depends on where you draw the lines.

A tiny fraction reach 500 and so far none that we know of have hit 5,000 though there’s a few possibilities.

This is really bad math, your calculation is not about bridge strength / longevity but about how many bridges we built recently.

For example, if tomorrow we decided to build a new bridge next to every old bridge, average lifespan would half.

current age != lifespan https://en.wikipedia.org/wiki/Life_expectancy

> if tomorrow we decided to build a new bridge next to every old bridge, average lifespan would half.

The only way building a bunch of new bridges changes lifespan is if we changed how they where built.

Figuring out lifespan rather than age is at best an approximation after looking at the bridges that didn't survive and the condition of bridges that do, but the uncertainty is low.

I'll raise you: https://en.wikipedia.org/wiki/Arkadiko_Bridge

But that's talking about the tail end of the bell curve not it's center.

That's also a much smaller scale. 22 ft long, 13 ft high, and carries only foot traffic or maybe horses. Much less is demanded of that structure than of a river-spanning mile-long truck-carrying bridge.

An obsolete or worn-out bridge is likely to be replaced by another, and in such cases, a risk analysis which potentially comes to different conclusions depending on how often such a replacement occurs is missing the point.

“Any idiot can build a bridge that stands, but it takes an engineer to build a bridge that barely stands.”

And in practice only bridges that "barely" stand are economically viable

> only bridges that "barely" stand are economically viable

That really depends on what is counted as part of the economy and who is doing the valuing.

I’m a huge “it’s capitalism’s fault” person, but this one feels mostly inevitable. Bridges are wonders of engineering that require this delicate balance, and I don’t think “just build em the old way” is an option. It’s not just price, it’s strength (for non-container-ship events…), span, height, construction time, etc. Obviously I’m in no place to evaluate the specifics of this bridge, and as someone from the SF Bay Area I know allll about corporate corruption fucking up expensive brand new bridges, but I feel like you’re yelling at the moon a bit here. Apologies if I misunderstood though!

well, "economically viable" doesn't necessarily mean scraping the bottom.

For example the great pyramids of giza are very solidly built. You certainly don't expect that level of build for every commercial or residential building out there.

Now, on the other end of the spectrum you can have buildings that can collapse on minor earthquakes.

There is a balance somewhere in the middle.

Yes, and it looks like it did take out an entire section. So it isn't like the ship just 'nicked' it and bent a few members. An entire support was taken out.

Which is why many bridges have stuctures around the pillars to avoid the direct collisions

Many homes also incorporate lightweight trusses that can fail in a similar fashion. They pose a unique risk for firefighters, which is why New York went so far as to require warnings be posted outside such structures: https://www.finehomebuilding.com/2015/01/28/new-york-now-req...

Check out Brick Immortar (it’s a pun) on YouTube for some in depth videos on past container ship collisions with bridges and how newer bridges are engineered.

Here's the one about the Sunshine Skyway Bridge collapse in Tampa Bay: https://youtu.be/3htwtaJI2nM?si=7SKMY2qxQEQpaf-O

It's pretty similar to this one.

People love bridges which look sleek, thin and like air. They are also cheaper (less materials). But this means there is no redundancy left.

The Mathews Bridge in Jacksonville was clipped by a container ship a few years back and did not collapse. Despite being almost 75 years old, they fixed it up and it opened back up after a year or two. The difference is that the boat did not hit a pylon.

There is this often in HN featured article about bridge engineer analysing bridge collapses in film [1]. It’s about suspension bridges though but the takeaway for me was that when they go they go completely.

[1] https://hackaday.com/2015/11/18/suspension-bridges-of-disbel...

At least in the links with the video now you can see that the container ship directly hits one of the two main (and in the central area only) pillars completely collapsing it.

No matter(1) the engineering there is no pretty much way to not lose the whole large middle area and left area leading to the destroyed pillar in that situation.

Such a collapse crates so much force (tension vibrations etc.) so that the collapse of the section right of the right pillar is not unreasonable.

The only question is if the impact should have made the pillar collapse.

But a loaded container ship is ... absurdly massive I mean they are like multiple high raise building (but not sky scrapers) standing squished together side by side. So the force it can apply is huge and if cargo moving in it there will be force applied to whatever it crashes into even after the initial impact.

And looking at the waves caused by impact with the base it was at least 8m high I think (depending on the container ship). So that wasn't a "slow moving" impact. And even slow moving impacts with container ships can tear apart a solid jetty.

So while the US has issues with infrastructure maintenance idk. if anything but building a many pillar bridge would have made any difference. And building a many pillar bridge might not be very viable depending on the under water landscape and water use under the main area.

EDIT: Looking at pictures with daylight where you can try to estimate the high of the ship using containers I would say the waves where handwavingly 4 containers high so ~9.5m and it also looks like the ship might have embedded half of the pillars fundament into/under itself (but it's a bit hard to tell to the angle of the picture). I think if that's the case probably the huge majority of bridge pillars of past and presence would have collapsed.

It certainly does not seem reasonable to design a bridge pillar to withstand a direct impact from a massive cargo ship.

But I guess I thought that maybe there was... typically some kind of earthen buffer around the pillar to prevent such an impact?

That's probably impractical too, I guess.

I guess I just didn't realize ~$1bn bridges were one fluky ship accident away from total collapse at any given time. I think maybe I prefer my previous state of ignorance, to be quite honest....

An earth buffer is just a bigger pier.

>>But I guess I thought that maybe there was... typically some kind of earthen buffer around the pillar to prevent such an impact?

It does look reasonable to have such a buffer. But any preventive measure will have limits as what and how serious an impact it can deal with.

In this case the ship this massive is something that is carrying ridiculous inertia, and its highly unlikely even a buffer could stop such an impact.

I think at some point you are better off solving these issues with more regulation(smaller ships)? Instead of treating this as a engineering problem.

It wouldn't take as much of a buffer to redirect the ship at an angle away from the pillar, would it?

I think this would be even harder. Whilst the ship has a lot of kinetic energy that needs to get dissipated, it also has a huge momentum that needs to be partly overcome to redirect it. You’d also need a material with enough structural strength to turn the ship. Materials that can crumple or deform (like huge concrete blocks or earthworks) are great at dissipating energy, but they aren’t great at deflecting things.

> But any preventive measure will have limits as what and how serious an impact it can deal with.

The recent grounding of a large container ship in Baltimore's harbor channel demonstrates that a sufficiently massive berm will stop any ship. What's needed is the will to do something about low-probability but catastrophic events (though large-ship collisions, groundings and fortuitously harmless steering failures are frequent enough that this should not have been dismissed as a low-probability event.)

https://www.cnn.com/2022/03/16/business/evergreen-container-...

In this case, the nearby towers supporting transmission lines across the channel seem to be better-protected against ship collisions than the piers of the bridge.

https://images.app.goo.gl/J6vTeDW5xjysbdjr9

The "berm" in this case happens to be the seabed of the earth. There's nothing bigger.

Of course - but it doesn't take all of it...

Starting from xoa's calculations above, assuming you can pack a berm with well-compacted soil enough that it can absorb 1,000 joules per cubic meter, you'd need a buffer of something like 10 meters surrounding each piling with 3 meters of depth to keep it safe from this kind of impact. That's 10 meters in every direction from the center of the support -- let's assume the support has a thickness of 0 meters for the sake of the math, and acknowledging that the gaps between structural supports on the bridge is approximately 30 meters -- the only way to protect it with earth is to make the bridge impassable by water. Of course, this would protect it from ship strikes.

You needn't stop the ship completely with the berm: just taking up enough energy that the bridge lives for 20 minutes after the impact would be useful.

Even if it takes 10 meters to get the job done (in practice, ships will not be coming at the piers perpendicularly to the channel), that is far from rendering the channel impassable.

Secondly, I believe riprap would be preferred to compacted soil (though compacted soil did a pretty good job stopping the Ever Given three years ago.)

Thirdly (and rendering the above moot), what's been done around the replacement Sunshine Skyway bridge in Tampa bay (mentioned in other posts here) shows that protection is, in fact, practical.

In view of these considerations, I'm not even going to check if, for example, xoa considered the energy absorbed by the ship (Update: in fairness, I did take a look at what xoa wrote, and I see that it is you who has introduced the figure of 1000 J/M^3.)

For an introduction to a serious engineering approach to this problem, look here:

https://onlinelibrary.wiley.com/doi/epdf/10.1002/stco.200910...

There are other issues with my work, namely that the central span is over 300m in width, not 30, as I had wrongly discovered, ergo the channel is passable even with my extremely half-baked solution.

That said, the dolphin-bulwarks around the Tampa Skyway are interesting. I've sailed through similar and not known their purpose other than to observe that local waterfowl like to line up at them ahead of tidal shifts to catch the fish as they're encouraged by the currents through them.

I have to say, you guys are all calculating things without any sort of deference to the nature of the soil underneath any of these piers or abutments. Also, you're both off on your other points as well. Sunshine Skyway has in no way been tested, and there are ways to "reinforce" earthen works so that they can handle more force so that you don't necessarily need 10 m.

You guys are doing amateur engineering. Firstly we don't even know what happened here yet. Secondly we don't know the nature of the problem we'd have to solve in protecting any span that would have been at that position. (How deep is the water? How far down to bedrock? Geological nature of the soil? etc etc etc)

It seems almost impossible for us as humans to just give the professionals some time and space to work so we can see what happened. I get that. I even engage in it at times. But you guys are stating things with certainty and almost indignation? Come on fellas.

Just say your peace and admit it's just a wild ass guess that's likely to be wrong in the end like the rest of our comments.

ETA: Thank you bmelton for owning that.

I'm not calculating anything; instead, I pointed to an article by someone who is involved in the real engineering of protecting bridges from ships.

FWIW, I think there are even more errors in my figures. That said, I wasn't trying to bunk or debunk, as much as the grandparent's comment intrigued me enough to wonder "What if earthen barrier?" -- how much earth would that take. My guess was that it would be prohibitive, and that 116,000 tonnes traveling 8.5 knots is just too much to stop. Earth obviously can, as whomever alluded to the Ever Given points out, but a lot would be required. How much? I don't know, but I was just trying to get an idea.

You're right that it's amateur. This isn't remotely what I do. To your point though, I don't have that much confidence that the Skyway bulwarks would do -- I'm sure they're more than adequate in preventing strikes from my 40' sailboat. Probably much more than that. My gut tells me they are inadequate to stop the momentum of 100k tonnes at speed, but if they did SOMEthing, perhaps that would be enough to differentiate between bridge damage and bridge collapse. I can't find any details on how it's reinforced, with what, or how deeply those reinforcements are buried, so this too is wild speculation... but I wonder if it isn't somewhat security theater. My wife is already scared of bridges, and we're Marylanders who frequent that bridge and the (much longer) bay bridge -- putting something down there to calm her nerves enough that she isn't panicking for the duration of every crossing is almost certainly worthwhile, but doesn't leave the nerds much to ponder.

> acknowledging that the gaps between structural supports on the bridge is approximately 30 meters

Measuring a satellite image in Google Maps [1] tells me the bridge's central span is more than 300 meters.

[1] https://maps.app.goo.gl/SzAzuzQRUwW7s2gN8

Yes, and that's an important correction.

I Googled the distances before the post but apparently got the wrong value. Danke!

You should look at the deisgn of old stone bridges. Their side facing up ( so towards the floods and ice) is like a wedge pointed upwards. So it's not like he bridge needs a buffer to fully stop all the forward energy. It can lift the object out of the water and maroon it there.

e.g. https://www.japantimes.co.jp/uploads/imported_images/uploads...

What's needed is the will to do something about low-probability but catastrophic events

In general I share your sentiment society could do more to insure itself against lower-probability catastrophes. But overbuilding every bridge would probably cost more than rebuilding the occasional one that's taken out when an unusual event like this occurs. Maybe in a different environment that would make sense, like a warzone (although I think even then there's more tendency to rely on redundant infrastructure and mobile, power-at-a-point defense).

When Florida's Sunshine Skyway bridge was partly collapsed by a similar incident in 1980, the replacement bridge was built with a series of "structural dolphins" and concrete barriers to protect against ship strikes. You can see them in the image linked below:

https://en.wikipedia.org/wiki/Sunshine_Skyway_Bridge#/media/...

> the replacement bridge was built with a series of "structural dolphins" and concrete barriers to protect against ship strikes.

Given how the Skyway collapse is burned into the local consciousness, I suspect some of the benefit comes from their visibility.

I truly don't know how the dolphins would fair against a massive ship strike but I can imagine them doing their job.

(ship passing): https://pbs.twimg.com/media/FPgQhy2X0AE8yw1.jpg

I would also add those barriers seem to depend on the ship staying intact during collision. Given the immense inertia involved on the bigger ships I could just as easily see a scenario where the barrier ends up ripping through the lower hull while the rest of the ship continues forward.

> easily see a scenario where the barrier ends up ripping through the lower hull while the rest of the ship continues forward

I don’t think that is likely? My intuition is that in order to stay seaworthy ships are constructed with more integrity than that.

I don’t have any hard evidence though, just that I have looked at many ship collision/allision aftermath photos and what you describe is not a failure mode I have seen so far.

See also: Titanic vs Ice

interestingly the bridge has such dolphins

but only on per-pillar per-direction and with quite a bit of distance between it and the pillar

one some pictures you can see that the ship barley missed one of them due to the angle it was going at

In smaller channels and similar it's not that uncommon to have crash barriers. For example in many Berlin channels and rivers.

And while I'm not quite sure what it is for the bridge had concrete pillars orthogonal in front of the pillars (this picture shows them well, to be clear I do NOT mean the power line isles: https://www.upi.com/News_Photos/view/upi/7191ba50f17c5a68307...). They would have stopped the ship if it would have went orthogonal to the bridge (i.e. if they mistook where the pillar where in a otherwise normal situation). Through not sure if that was the purpose of them.

> So that wasn't a "slow moving" impact

Exactly. It is only the scale and the viewing angle that makes it seem slow moving.

Just to put some numbers on this:

The MV Dali (IMO#9697428) is a little over 95000 GT, or ballpark-ish probably around 114000 tons loaded (and it seems to have been loaded, which would make sense on departure). If it was going even 5kn (2.6 m/s) that'd be about 300 million newton-seconds, or about 3.3 times the momentum of a large jumbo jet like a 747 shortly at cruising speed (around 560 mph). It'd still have the same momentum as said jet if it was going just 1.5kn. The ship of course is enormously more stoutly built and the force is going to be transmitted far more directly into whatever it hits vs into explosions driving mass elsewhere.

I've read that both on water and in space for that matter enormously massive objects moving very slowly messes with human perception and "common sense", it "feels like" something moving along smoothly and slowly should be stoppable or come to a stop. Enormous momentum and forces can be terrifying things.

> enormously massive objects moving very slowly messes with human perception and "common sense"

Yes, hence warnings to amateur boat users (e.g. on a canal boat) not to try to stop a collision with the bank using your arms or legs.

[Edit] Boats can also do things that are unintuitive if you are used to driving a car. E.g. turning round the centre of gravity when you steer rather than following the front wheels.

In the black powder era of warfare, soldiers were given similar warnings about “slowly” rolling cannonballs.

People would think they could stop them like soccer balls, and lose a foot.

There are similar warnings for sailing vessels, but because the standing rigging of the ship is usually kept in high enough tension that putting your hands on a pilon to stop a collision might leave your hands vulnerable to being cut off by a mainsail's shrouds.

Ouch! That reminded me of seeing someone get a rope burn from a line on a yacht. I always wear gloves when handling lines on a boat nowadays.

I had a summer job once, filling trains with sugar. They weighed about 15kkg per wagon (usually 5-10 wagons per train IIRC).

One time the pulling cart broke down and we had to switch it for another, but when we took it off the rails we forgot about the "shoe" that is supposed to go between the rail and one of the wheels so it can't move downhill (it was like 1degree of slope so barely recognizable as a slope).

It started moving extremely slowly, and all of us except one tried to hold back the force of the train, which of course was imossible and dangerous. The one who did not try to push it very quickly found the "shoe" and put in place. Initially it did not seem to help at all, the train just continued moving at the same pace, tearing up asphalt with the shoe. It finally came to a stop after about 3-5m(?) which takes a fair bit of time with such low speed, and felt like forever given the situation.

The train tracks headed out into an open road, so it could have been so much worse if it were not for the only person thinking clearly in the situation (he was one of the more experienced in our group).

Also want to highlight this for another reason. At slow speeds rail and boats suffer from far less “moving” friction than road vehicles. So once off there is very little slowing them down vs cars and trucks that suffer from high rolling friction.

Grady Hillhouse of Practical Engineering recently did a great demo of this. He was able to pull his car in neutral and an empty train car on rails with roughly the same force.

https://www.youtube.com/watch?v=nGhBHrr5CYQ

One wonders how braking works on a train.

Mostly the same as it would work on a car with a brake shoe applied to the steel wheel.

The only major difference is that they often use a safety air brake system shared across an entire consist (train) that requires “charged” pressure (above atmosphere) to disengage the brake (although I think they have moved to an electronic system that now monitors air pressure in each car individually).

Semi trucks have air brakes that function very similarly. One air source for all brakes, pressure releases, brakes lock on failure.

I think it's actually in an earlier video, and he wasn't able to actually pull the train car due to track irregularity -- but according to calculations he should have been able to if there was a safe way to give it a bit of a nudge.

You're absolutely right; I posted the wrong link.

https://www.youtube.com/watch?v=tfA0ftgWI7U

> all of us except one tried to hold back the force of the train

This reminds me of a vivid memory I have. I’d just finished a shift cooking, and out back of our restaurant there were railroad tracks. I had a beer and smoke out there with my shift mate, and a train was rolling by. I thought it would be fun to practice jumping on the train. So I do a few passes jogging alongside it, hopping on and off. Then my buddy, standing still, reached out and grabs a rung of a ladder on one of the cars. It immediately picked him up, but he gripped harder due to being startled. He got ragdolled through the air about 10 feet from where he was initially standing.

Kids, don’t play with trains (trespassing issues aside).

A friend of mine was on the light rail here downtown when it stopped unexpectedly. He was confused and walked outside only to see the train had hit a fire truck and pushed it nearly a block before it stopped. He had no idea there was even a collision inside the train.

Trains are very scary stuff even when moving at a crawl.

A 110,000 ton ship collision is something the human brain is just not going to understand intuitively.

> If it was going even 5kn...

I don't know what sort of speed ships travel in harbors (though I know that they are faster than they appear.) In this case, it was an ebb tide (though within an hour of the low) which might have added something to the ship's speed.

https://tides.willyweather.com/md/baltimore-city/patapsco-ri...

Thank you, I've been trying to get a ballpark on the weight, appreciated.

According to https://gcaptain.com/ship-lost-control-before-hitting-baltim... they were going 7.6kn so your figures are “optimistic” by a factor of two. I really don’t know how much an engineer could have done to stop 600M N/s - that’s just an enormous amount of energy.

<checks terminal> "current draft is 12.2m with 116851 t DWT" and last reported speed was 6.7kt.

Good estimation! :)

I saw radar that showed the ship was going 8.7 knots. And 7.6 knots before colliding.

Crazy! Going by the higher 7.6 kn figure mentioned elsewhere in this thread, that'd be closer to 450 million N s.

For another comparison, Wikipedia gives an estimate of "Apollo 11 launched from Earth to orbit" at 495 million N s [1]. So this is a momentum that's order-of-magnitude comparable to space launches.

[1] https://en.wikipedia.org/wiki/Newton-second

Your math appears off by an order of magnitude. KE = ½mv^2. [J]

Ship KE = 0.5 * (114000 short tons) * (7.5 knots)^2 = ~7.7e8 J.

747 KE = 0.5 * (510,000 lbs) * (560 mph)^2 = ~7.25e9 J.

747 avg weight = (MTOW + OEW) / 2 = ~510,000 lbs

You don't need to build the bridge to an absurd strength, but it may have been insufficiently marked as a navigational hazard. Something like a few well-lit pillars 500 feet upstream in the water would have given the ship plenty of warning to change course, since a vessel travelling at 5 knots takes about a minute to go 500 feet. The total bridge length is on the order of 10,000 feet, so widening the safe area around the pillars to 500 feet would not be a significant impediment to navigation.

I've seen close-up video where you can see the ship losing electrical power twice for not-insubstantial times as it approaches the column. I suspect that was a much larger factor in the collision than anything the crew may or may not have done. Warning time doesn't mean shit if you can't steer.

https://twitter.com/ChaudharyParvez/status/17725385394958090...

Posted video of power loss. Also black smoke coming out rear — is that normal? Any clue of what onboard crisis they were dealing with?

It seems traffic has stopped in the last moments before the hit?

Also looks like it's emergency vehicles in standstill that are falling, i can't discern any moving cars at collapse?

I heard through the grape vine they were able to halt traffic across the bridge at the last minute. Only people actually on it when it fell were construction workers who were filling potholes at the time.

The ship's mayday gave them enough time to stop most, but not all, traffic, according to the MD Governor.

seems like they should have turned left and tried to go under the middle section there instead of cranking all the way around right. I imagine they were under task saturation with the power outages though.

I think we should restrain ourselves from armchair judgements when basically no one here is a harbor pilot, let alone someone informed with what was happening in the moment in this event.

What happened will be meticulously reconstructed and everyone involved in this is going to have their lives put under a microscope for years worth of legal battles. I don't think we should rush to judgement or second guess from a position of ignorance.

The black smoke is most likely them running the engine in full reverse in an attempt to avoid the collision.

I mean, yes, everybody is pointing out about the mass of the container ship, but that's actually to the point of the above question and my question. Because the ship's size and weight are obvious. Were ships this size regularly passing by or under this bridge such that this scenario was effectively bound to happen given a ship failure and/or pilot error? That's my question. I'm not familiar with port activities, so it seems weird to have basically no secondary protection for that bridge with container ships of that size operating so close that they can hit it mere minutes after some failure.

Watching this video (https://www.youtube.com/watch?v=qJNRRdha1Xk) shows that the ship was incredibly close to the bridge in the first place, even prior to the supposed failure. It's a bit bewildering to me, with my current knowledge, that this scenario wasn't envisioned prior.

That was my thought. The supports look like toothpicks relative to the ships that routinely pass through. I don't know enough about the forces involved here, but I'd like to think when they rebuild, they will add some sort of deflection capabilities around the supports that ships must past in between. But again, I don't know what that would take to deflect a massive ship like this. In hindsight, the bridge looks terribly exposed given the persistent risk of ships passing through.

I did hear one expert on the news say that a better, low-tech defense some bridges have is sacrificial piers in front of the actual ones. I don't know if this bridge had none, or if they didn't get the job done.

The Bay Bridge in SF has been hit by numerous ships (as large as tankers)

The 2007 Cosco Busan incident appears to be a glancing blow. I can't find any information suggesting an analogous impact at any point.

> It’s surprising that ships capable of doing this damage were probably regularly driving past it, and its safety as a thoroughfare depended entirely on those collisions not happening.

There are cities with skyscrapers near airports, which depend on the airplanes not hitting the skyscrapers.

I don’t drive boats or around water much but I’ve seen “bumpers” on bridge pylons before that make a collision more of a glancing blow and guide the boat to the side. I guess there wasn’t any installed on this bridge? Also, someone on Imgur pointed out that when this bridge was built boats that large weren’t a risk. That may or may not be true but sounds plausible.

> when this bridge was built boats that large weren’t a risk

Doesn't sound plausible to me. Very large Panamax ships were used in the 1970's when the bridge was built.

Sorry, but you're very wrong. A civil engineer on Sky News even raised this issue.

https://www.container-transportation.com/worlds-largest-cont...

Panamax specifications (320 m length, 32 m width) have been in effect since the opening of the canal in 1914. Some ships were already larger than that back then. The Titanic was about that size.

The ship that knocked down the bridge could weigh ("DWT") up to 115 000 tons.

Some ships from the 1960s and 1970s:

Universe Ireland: Launched in 1968, it had a DWT of over 300 000 tons.

Esso Atlantic (1977): DWT of over 500 000 tons.

But these were tankers. You're right that container ships were not as big back then.

One of the larger container ships when the bridge was built in 1977 was MV Hamburg Express. It was 280 meters long, 32 meters wide, and had a DWT of 50 000 tons.

Do you really think a 280 meter long ship weighing 50 000 tons would not have knocked down the bridge in exactly the same way?

https://de.wikipedia.org/wiki/Hamburg-Express-Klasse_(1972)

There were tiny bumpers, two for each pylon, one on each side, but looks like they were place too far out, you can see them here...

https://i.pinimg.com/736x/1c/6e/f8/1c6ef8db981c77b1bd7809827...

Ironically there are power lines running in parallel that have much more substantial protection, here you can see the powerline protection and the tiny bumpers...

https://patabook.com/news/wp-content/uploads/2024/03/cbsn-fu...

Fenders and such. A major problem is this bridge was designed and built in an era where ships were substantially smaller (3000 TEU) than they are today (20000 TEU).

The ship that brought down the bridge had a capacity of 10 000 TEU. It's max weight (DWT) was 115 000 tons.

There were container ships with a DWT of 50 000 tons when the bridge was built.

There were also tankers with 10x that (500 000 tons), so large and heavy ships shouldn't be a Pikachu-face surprise to the bridge designers. If nothing else, the trend in increasing ship sizes was clear to anyone looking at it.

Do you think the bridge steel pylons would have resisted a 50 000 tons ship plowing into them?

In 2013, a tanker ship hit the Bay Bridge (Oakland <--> SF) but didn't do much damage. In 2007, another tanker (Cosco Busan) hit the same bridge dumping oil into the bay: https://www.youtube.com/watch?v=upfjxfl2nRM. We have a new bridge there now because that one was also damaged in the Loma Prieta earthquake.

When the Golden Gate needs replacement, the Marin NIMBY's that didn't extend BART to the north bay are going to be sad (more likely, their children will be).

This brings back to memory 911 conspiracy theories.

Many revolved around the unlikelihood that a building would collapse the way the towers collapsed just due to knocking out a few floors at the top. But the truth is all these mega structures are quite fragile and can instantly collapse in unintuitive ways.

The ongoing construction work likely creaty some type of structural integrity issue...

In many structures, catastrophic failures are far more likely than graceful failures.

these ships have to be boarded by special port captians to make this maneuver.

One factor that a lot of people in this discussion are missing is that buildings are primarily built to resist vertical forces, because gravity is by far the largest force any building (or bridge) ever experiences.

Having a large force strike perpendicular to gravity is just not something it's designed for at all. All it ever has to handle in the form of force from that direction is wind, and that's absolutely nothing compared to a fully laden container ship hitting it.

That bridge looks like its almost entirely made of just trusses. It's hard to imagine how one might expect it not to collapse when everything holding it together is so thin.

Ironically, simply bulking up the ground around the piers would have had the ship run aground; at 8 knots the ship would have slowed to a stop within several yards, and suffered minor damage, maybe would have required being tugged back into clear waters. Running aground puts the majority of impact into a downward force absorbed by the earth. It's hard to build a bridge pier that will withstand 200,000 tons of direct impact, no matter how slowly that's moving.

That's what makes sense to me. Ships are designed to minimize drag going through the water. But the friction of the entire hull scraping across the bottom should be MUCH larger and thus able to exert lots more stopping force.

Also, if the ground is sloped, it will act like a ramp, lifting the ship out of the water. The loss of buoyancy means its weight will push downward on the ground below it. An increased normal force means more friction, thus more stopping ability.

> simply bulking up the ground around the piers

That is exactly what they did around the pylons of the large Öresundsbridge between Denmark and Sweden.

Simply bulking up the ground around the piers with loose fill or monolithic concrete would have had the ship run aground; at 9mph (the recorded impact speed) the ship would have slowed to a stop within several yards, and suffered minor damage, maybe would have required being tugged back into clear waters. Running aground puts the majority of impact into a downward force absorbed by the earth. It's hard to build a bridge pier that will withstand 200,000 tons of direct impact, no matter how slowly that's moving.

separate but pertinent question: what was the mv dali's air draft? (FSK bridge's clearance is 185'/56m) was the container ship going to fit under the bridge, i.e., perhaps the incident was an aborted attempt to crossing under the bridge?

I'd assume the procedure of how the ship will enter and leave was clear to all involved before it even got close to Baltimore.

separate but pertinent question: what was the mv dali's air draft? (FSK bridge's clearance is 185'/56m) ...perhaps the incident was an aborted attempt to crossing under the bridge?

Anyone know about backup steering power on these vessels? I know they typically keep emergency generators, but does this provide adequate steering power?

Someone hasn't played enough polybridge

Is there a reason we don't force ships above a certain side to always approach a bridge like this perpendicular in the main channels? Seems like a trivial thing to implement immediately and makes this never happen again.

If you watch it in slow motion and how it breaks apart, you won't really find it surprising how things snap and bend considering how big the container ship is compared to the bridge. It makes a lot of sense.

DALI (IMO: 9697428) is a Container Ship and is sailing under the flag of Singapore. Her length overall (LOA) is 299.92 meters and her width is 48.2 meters [1].

Based on the track, it appears the ship changed course slightly and slowed as it approached the bridge [2].

[1] https://www.marinetraffic.com/en/ais/details/ships/shipid:28...

[2] https://www.marinetraffic.com/en/ais/home/shipid:2810451/zoo...

That's clear in the livestream video too. It's like it was fairly on track then changed to head straight for the pylon. A lot of smoke starts coming out of the funnel at the same time as the course change, and the ship's lights go out before impact.

It appears to have lost power twice before veering into the foundation of the bridge..

How often would a large ship like the is lose power? Seems like terribly poor timing.

Problems are disproportionately likely to show up right as you start out on a journey.

I had assumed this was coming in, but starting out would make more sense.

Thanks for the link to the track. That's the first thing that I've seen that showed that I guess it's regular for these ships to pass under the center of this bridge. Is that correct?

If so, what I'm still not understanding is why ships are allowed to make that passage all on their own without any backup like a tugboat and why the bridge doesn't have secondary protection of its pillars. Because with a track like that and lack of either of those things, a catastrophic collision seems inevitable.

Does anyone know why the ship would make a sudden hard right during a sequence of power failures?

This is a tragedy for those involved.

My rough calculus points that the amount of force of this collision is on par with a large scale natural disaster. Everyone being surprised at the bridge collapsing needs to reconcile with the amount of force that struck the bridge - it is a truly significant amount of Newtons that hit the bridge. More than a train going from full speed to a full stop. Unbelievable amount of force.

I am also a bit surprised at how many people don't grasp this or grasp engineering, magnitude of forces and design principles.

And many here have engineer in their job title.

There are a lot of types of engineering, and some of them are VERY far away from civil/structural engineering.

Your last sentence is pretentious and condescending.

To be fair I am truly surprised at the comment thread here and people being surprised that it collapsed and the lack of understanding of magnitude of forces. I always think of HN as a fairly educated group with a large portion of engineers (skewed heavily towards software which doesn't always have a background in the physical environment).

I don't intend to sound pretentious or condescending. Maybe its more that I need to reconcile with my own expectations of the community level of knowledge/domain of expertise.

I rather have a high bar of expectations than a low bar though to be honest.

The absolute mass of container ships are inconceivable by default - it's really worth repeating how much weight and force they bear.

It's likely that a lot of people don't understand just how huge these ships are. I'd imagine that much of HN doesn't have a ton of firsthand experience with shipping yards or even close friends/relatives that work on these things. In my experience, almost nothing hides just how large it is than a giant ship.

That's fair. If you don't live in a major port city you likely don't understand.

Maybe we should reframe it to a more familiar territory. It could be the equivalent of a second tier unsophisticated, unsuspecting, dated website with a relatively small amount of traffic hitting it being hit by a state sponsored actor DDoS attack and expecting the website to survive.

I'm with you on this one, I grew up around boats and remember the dread of even getting near a containership in a 16 foot Boston Whaler. That fear was more primal and daunting than sailing home during a tornado watch.

My family and I drove through the Ports of LA/Long Beach on vacation last summer. A port is basically an entire city dedicated to getting things in/out of the water. Takes 15-20 minutes to drive through. You can't imagine the number of cranes/lifts. It's worth the drive through.

This ship was carrying ~5,000 TEU (Trailer Equivalent Units). Imagine 5,000 fully packed semi trucks crashing into the single upright of that bridge.

Even at 7.5 knots (~10mph) the bridge stood no chance.

Would it even stand a chance at 1 mph? If not, what is the speed that would make it imaginable for the bridge not to collapse?

When I was a kid, we would go fishing off of pier near a port. The size of carriers and tankers is staggering. And if you get close enough to see numbers and lines near the front of the boat, you realize that fully loaded these things are 30 40 ft underwater.

> Everyone being surprised at the bridge collapsing needs to reconcile with the amount of force that struck the bridge ... I am also a bit surprised at how many people don't grasp this or grasp engineering, magnitude of forces and design principles.

A spokesman for CalTrans claimed today that Bay Bridge could have taken the same hit without damage, thanks to fenders that protects all pylons for all bridges in the San Francisco Bay Area (1). Cargo ships are heavy, yes, but it appears we have the technology to prevent bridge collapses due to these sorts of collisions today.

1. "The Bay Bridge’s fenders insulated the span during the 2007 incident, so that the Cosco Busan ship struck a bumper, never hitting the bridge itself, Ney said. He noted that fenders on Bay Area bridges should be able to handle a ship traveling at 8 knots, the velocity at which the ship hit the Francis Scott Key span."

https://www.sfchronicle.com/bayarea/article/baltimore-bridge...

"A ship traveling at 8 knots" is a meaningless statement. You need to know how bit the ship is...

Container ship

Thanks to things like planetwide bottlenecks through specific canals and locks and design of certain ports, approximately all container ships are within a couple meters of one of only a handful of size buckets, several of which are fairly close to each other besides. For example, a large fraction of the world's container ships are sized to be within a meter of fitting into chinese port facilities and the suez or panama canals. Because these dimensions include the depth of the water as well as the length and width of the ship they also limit the total volume of water which is available to be displaced, which puts a limit on the total mass that can be floated. As a result, "a container ship" is actually a fairly tight and predictable specification of a ship's maximum mass!

That may be so and I appreciate CalTrans confidence in the matter. I however would never want a similar set of circumstances to strike the bay bridge and have to test it.

It is a very different bridge design (assuming were talking about the Oakland to treasure island portion) and it is built in earthquake country.

I'm not saying there shouldn't have been fenders or other protective measures. I'm saying that the amount of force on a direct hit that STOPPED that the ship dead in its tracks - that bridge was not going to withstand it and I do question what would happen to the bay bridge. Again I appreciate the confidence of CalTrans to reassure the commuters but I have seen government officials express too much confidence before.

> More than a train going from full speed to a full stop.

I wonder. This ship might have massed about ten times a typical freight train on the heavy side, but the train is going to be moving a lot faster than a ship navigating in port, right?

> I am also a bit surprised at how many people don't grasp this or grasp engineering, magnitude of forces and design principles.

Who are you even referring to? Are you just inventing a population of people in your mind to flex against here? Trust me, people get it.

Seems a bit gauche to link to them, but there are comments all over this thread, including top level ones.

For an assumption to get a gauge of forces involved: Large cargo ship mass is 190,000 tons @ 8 knots (14.8 kph) - I end up with a Force of about 1.609 * 10^9 or 1.6 GN of force of impact assuming it stopped over a very short distance (1 M).

Force comparables (thanks GPT) for scale: Saturn V rocket thrust is about 34 GN on take off.

Earthquakes: early stage of the earthquake might have about 1 GN of force in build up.

Great pyramid of Giza is estimated at 50 GN of weight - so 1.6 GN could support a fraction of the weight.

Engineering machinery - some of the largest human machines such as mining or lifting can exert forces only in the MN so would need a 1000 machines to get up to a GN.

I've seen a bunch of weight numbers but it's around a billion joules, the equivalent energy to a Mk83/GBU-32 1000lb bomb (200kg explosive fill).

Is force really the right dimension for this kind of analysis? I was thinking more in terms of energy deposited into the system.

You can look back on the livestream here to see the collision and collapse.

https://www.youtube.com/watch?v=83a7h3kkgPg

Collision is at 1:28 EDT; you'll need to go back in the livestream.

Here's a clip from that livestream of the collapse, clipped by The Guardian: https://www.youtube.com/watch?v=YVdVpd-pqcM

The lights on the ship were going off and on, and it appeared to be smoking before hitting the bridge. Does not look like they had much control at the time.

Could it be that the power going off and on, and the smoke came from a panicky attempt to recover from a mistake and avoid hitting that bridge ?

The power going off is most likely what caused the accident.

Most likely it was engine failure which caused the steering to lose power and allowed the ship to be pushed by the current.

The dark smoke was most likely the diesel generator firing up to get some steering control back

Clip here, beginning at 1m23s, shows a (sped-up) edit of the ship approaching the bridge, with lights going out, on, and out again immediately prior to impact:

<https://yewtu.be/watch?v=Cs6PrRiIHEw&t=1m23s>

Curious, is there a specific reason you put links between < and >?

In markdown (or at least some flavors) that is the typical way of making a hyperlink actually a link. It's equivalent to [link](link) in markdown.

Angle brackets are used for "naked" URLs & email addresses in Markdown:

<https://www.markdownguide.org/basic-syntax/#urls-and-email-a...>

It was the standard way to format URLs on Usenet. GP is at least 40 years old.

Bless you.

Similar using " " to quote for reply vs. >.

Carry-over from Markdown, and it appears to help HN's URL parser in some instances:

<https://news.ycombinator.com/item?id=32745065>

RFC 3986, from 2005: “Uniform Resource Identifier (URI): Generic Syntax”:

    Using <> angle brackets around each URI is especially recommended as
    a delimiting style for a reference that contains embedded whitespace.

<https://datatracker.ietf.org/doc/html/rfc3986>

Not sure how to yt-dlp a big section of that video without downloading hours and hours... I found this tool but not going to install C# for it.

https://github.com/rytsikau/ee.Yrewind/

Collapsed because a container ship ran into it.

“ The Francis Scott Key Bridge in Baltimore, Maryland which crosses the Patapsco River has reportedly Collapsed within the last few minutes after being Struck by a Large Container Ship; a Mass Casualty Incident has been Declared with over a Dozen Cars and many Individuals said to be in the Water.”

I had a hunch this was the bridge featured in The Wire s2e1, "Ebb Tide". Classic McNulty; a great season opener.

https://en.wikipedia.org/wiki/Ebb_Tide_(The_Wire)

Greatest tv series ever. And when you rewatch it, you notice new things.

+1 I recently watched the whole series again after I subscribed to HBOMax. I hadn't watched it since 2008, when I watched in SD using DVDs from my original Netflix subscription.

Aside from the new story details I caught and the general great acting, I was struck by how the series captured a the technology transition going on at the time. Payphones and typewriters shift to classic feature phones and PCs with CRTs. Then camera phones enter the picture.

Season 2 of The Wire is the single greatest work of television I've ever seen. It's as rich as a novel, as tragic as something out of Shakespeare. Seriously. If anyone hasn't seen The Wire, do yourself a favor and give it a watch.

It's always wild that Season 2 seems to be polarizing, it is very different but it's so compelling. Tragedy is really probably the most complete way to describe it.

But yeah the short scenes of "that's my f*ing town" and the "they used to make steel there, no?". I know the first one takes place right next to the bridge because they say they are at Fort Armistead. I assume the latter is in much the same place since I thought they are looking across the river at Sparrow's Point.

The great thing about Season 2 of The Wire is that it works well both as a standalone mini-series and as a segue from Season 1 to Season 3.

Aside from great acting and direction, of course.

Also relevant to season 2. The US seriously lacks dredging capacity, because we only allow US built dredges to operate on our ports. Only 1-3 of the top 50 highest capacity dredges in the world qualify. Bloomberg Odd Lots has a great episode about this.

https://omny.fm/shows/odd-lots/the-1906-dredging-law-that-ma...

The design of the Chesapeake Bay Bridge-Tunnel, specifically the tunnel part, makes a lot of sense now. Imagine a US navy port (Norfolk) being inaccessible if this happened there.

Right? Clearly it would be a significant national defense risk. Also allows for larger ships to get through.

That said - It also makes for a very enjoyable drive with children - probably their main design parameter right?

Which is why there's a tunnel -- when Virginia looked at replacing the ferry that ran between the Eastern Shore and Norfolk/Virginia Beach, the US Navy objected to a bridge over fears it could collapse. (An accident, sabotage, etc.) That's also why I64 has a bridge-tunnel design, as well.

The Navy has long required that the sea lanes from the Norfolk Naval Shipyard and Newport News Shipbuilding to the ocean have a deep-draft passage with no bridge, for just that reason.

This was also a major concern around the construction of the Golden Gate bridge; that during a time of war an enemy could have destroyed it to trap a large portion of the Navy's Pacific Fleet in the bay.

According to this Baltimore news report, after 9/11 state officials had looked at putting bumpers around the piers that could have protected the bridge from an impact like this, but it was too expensive.

https://www.youtube.com/watch?v=l_-CpdVaHGg

Even compared to the economic impact of a bridge collapse and resulting port closure?

Yeah I'm guessing just replacing the bridge will cost a lot more than the bumpers would have, even without counting the broader impacts.

Supposedly "state officials" shot down bumpers on cost. They made a bet and it turns out that they've won: Biden has committed to paying the entire cost of replacement[1]. Instead of investing in bridge defense to protect a 50 year old bridge and its ever increasing maintenance costs they get a brand new bridge for free!

[1] "It is my intention that the federal government will pay for the entire cost of reconstructing that bridge, and I expect the Congress to support my effort"

How could one build a bumper to protect the piers from an impact like this? That ship is massive and it sounds like it was going pretty fast. I'm having trouble imagining any solution that involves absorbing the impact. But I'm not a civil engineer. If something like this exists I'd be interested in reading about it.

The bumper may be crushed and may need to be replaced but the best outcome is that it redirects the majority of the force away from the critical support structure of the bridge.

The boat changes direction after impact with the bumper

It was a massive boat. They don't change direction very easily.

Well engineered small things can redirect a moving thing several orders of magnitude more massive. Consider guardrails on the side of a road; those guard rails might be less than 100 Kg but together they're rated to redirect the force of a car weighing thousands of Kg traveling at tens of K/h. That's a lot of force to redirect for such a small and cheap barrier; imaging what a more expensive and larger barrier can do.

Turning in water is a lot harder than turning a wheeled vehicle on land. Cars can turn themselves in a tight radius, container vessels cannot.

I also don't think the weight of the guardrail is what matters. Its strength is derived from the strength of the materials and being anchored in the earth.

In any case, any vehicle driving directly into a guardrail is going to plow right through.

I just don't think this guardrail thing is a great analogy.

They're a pretty good analogy because you use a deflector style guard in the bay that ALSO is anchored in the earth. Nobody stops a whole cargo ship traveling straight at a thing via brute stopping power. You don't do it with cars and you don't do it with boats. You use deflectors that are roughly parallel to the direction of travel. Otherwise, all you can do is build a giant bunker which is not cost effective.

The bumpers are also massive. They're large concrete pillars. Here's video showing what they look like on similar bridges around Baltimore.

https://www.youtube.com/watch?v=dFl412SuWZE&t=41s

Amazing how many people are shocked that the bridge collapsed like that. That was one huge ship! Bridges are in a carefully balanced state of tension and compression, if anything as significant as a large container ship upsets that, I'd be shocked if it survived.

Yes, I saw and 'engineer' on the news who said he was supprised it collapsed after the loss of the support... I can't even fathom how you could think the bridge could levitate on one support.

I heard on the local radio here, with one of the DJs being an ex-cop, his contact with EMS said the driver of the boat called a mayday and said to clear the bridge. Nope, can't prove it, but I imagine it'll come out in the news soon.

So, not intentional.

Sounds like they were able to stop traffic in time, which is why they know the precise number of missing people.

They were construction workers fixing potholes.

I'd expect that they have traffic cameras on the bridge that would allow them to know how many cars are missing.

This port has a very large volume of car shipping. The ro-ro shipping costs are expected to go much higher as a result of this accident.

If you were in the market for a car in the US east coast , act now before prices go up!

A bunch of people die and this is your response?

It sucks they died; but our life goes on.

For almost all of us, there's nothing we can do to help anyone immediately effected by this incident. Would you have everyone else stand idle in mourning and respect? For how long?

More than a couple hours I guess

The shear volume of death everyday is mid blowing.

I don’t see any benefit to anybody to just ‘stop’ when a small number of those deaths happen in an exceptionally dramatic way.

The repercussions of this accident could very well kill more people indirectly than the actual workers who died.

I don't see a benefit to it either, but I still find it surprising when people react to tragedy with zero sympathy or emotion beyond self preservation. My surprise was all I was trying to indicate with my original comment.

The tentacles of this tragedy reach out far beyond Baltimore.

I saw someone speaking of how their shipment of body pillows was on that ship and they'd be liable for customer refunds now, possibly breaking their business.

People working at car dealerships all over the East Coast now have customers they're going to have to disappoint, one way or another.

Where's your sympathy for the people attempting to deal with the ongoing consequences of the crisis?

You're making unfounded assumptions about my sympathies. As I mentioned in other replies to this tree, my first comment was simply expressing my surprise to the top level comment. The top level comment said car prices will be affected so you'd better go shopping now. If it had expressed sympathy for people other than car consumers I might not have reacted that way.

Either way, I don't think loss of life is equivalent to having to disappoint your customers due to price inflation, so I reject your suggestion that my sympathy is misplaced.

There is no reason to expect someone to have a rational approach to transportation-related fatality in any direction.

Drunk drivers will kill approximately 40 people today in America. Most people won't care about that or demand a congressional response or blame politicians, etc., so it is no more heartless to not care about a few dead people on a bridge either.

Sure, the difference is that when I hear about drunk driving fatalities I don't immediately jump to economic opportunism.

Most people do, actually, care about drunk driving accidents.

People die all the time dude.

Wait what?

This has been confirmed by local authorities:

https://www.cnbc.com/2024/03/26/major-bridge-in-baltimore-co...

https://twitter.com/TheMDTA/status/1772524001815920876

As of right now, that page starts out with a photo of an entirely different bridge of the same name from Washington DC, quite confusing.

https://en.m.wikipedia.org/wiki/Key_Bridge_(Washington,_D.C.) (hn breaks the trailing parenthesis in the link)

Edit: they removed the photo.

Yeah I've encountered url parsing problems on hn before too -- it pays to always check your links. It forgot the . too, which made it think the url was over! You can use percent encoding in such cases -- . is %2E and ) is %29:

https://en.m.wikipedia.org/wiki/Key_Bridge_(Washington,_D.C%...

I was wondering after watching the video whether there could be an emergency bridge closure protocol if a ship veers off its intended course. It naively looks to me like there would be sufficient time to log the course deviation and stop vehicles from entering the bridge with lights and sirens and stuff.

How could the cost of this possibly be justified?

Why would it be expensive? Traffic lights and sirens are cheap. The Tasman bridge apparently stops traffic for all large ships https://en.m.wikipedia.org/wiki/Tasman_Bridge

Also had a disaster. "The Tasman Bridge gained national attention following the Tasman Bridge disaster. On 5 January 1975, the bridge was struck by the bulk ore carrier SS Lake Illawarra"

And will you also be revealing the cost of stopping traffic versus the expected loss of what it prevents?

How many people would need to die for it to be justified in your eyes? Or maybe just focus on the potential loss of cargo from trucks on the bridge, if that helps you.

How many? It depends on the opportunity cost of installing and maintaining whatever half baked thing (lights, sirens, computer vision, AI, barriers) it is OP is envisioning on how many thousands of bridges versus the frequency of issues it will prevent. This calculation is done all the time but not so much by the "if it saves only one x" crowd of clever solution proposers.

> whatever half baked thing (lights, sirens, computer vision, AI, barriers) it is OP is envisioning

Do you think OP should have produced a formal proposal with input from industry experts and detailed cost and risk mitigation figures before submitting a comment on an internet forum?

Either that or another ten seconds of rumination.

There's no requirement for you to be pleasant on an internet forum, but there's no reason not to be either. Snark is rarely becoming.

> It depends on the opportunity cost of installing and maintaining whatever half baked thing (lights, sirens, computer vision, AI, barriers)

I love how we jump to AI when all we need is 4 cameras and a dude with a pair of eyes...

Wait until you learn how train barriers worked not so long ago

Large bridges like this in Europe already have lights and sometimes barriers to allow them to be closed if there are very high winds, or a vehicle collision.

Adding a system that turns the lights red doesn't seem so expensive, it existed in Denmark in 2001 when a ship almost hit the Great Belt Bridge:

Road signs and barriers, normally used to slow traffic in bad weather [1]

(Autotranslation of [2])

> The VTS system (Vessel Traffic Service) must monitor and guide the ships, so that ships approaching the West Bridge and parts of the East Bridge can be avoided. In the event of danger of hitting the bridges, the navigators must trigger an alarm in accordance with detailed rules. The most critical are two bridge sections on the East Bridge over the connection spans to the anchor blocks (each 1-2 kilometres). If a ship is heading in there - where there are no artificial islands - the alarm must be given four minutes before approaching - so that the bridge section can be cleared. On the West Bridge, the warning time is not so critical, as you can see in good time if a ship is on the wrong track. The system operates using three radars, two infrared video cameras and two photosensitive ditto plus a standard VHF antenna system (see graphic). The station is continuously in contact with all ships over 50 gross tonnes and with a mast height of over 15 metres. The ship's call number, name, cargo, destination, draft, mast height, etc. are registered on arrival at the reporting lines, and when the ship and station are contacted on VHF channel 11, the ship is automatically marked (tracked) and provided with the call number, course and speed. At the same time, the computer goes in and calculates course and speed for the next 10 minutes, which can be seen as a yellow line in front of the radar signal, which is shaped like a tuft of wool. If a ship does not want to report, goes astray or refuses to follow the VTS navigator's instructions, the VTS station disposes of one of the fleet's rejection vessels, which has the authority to give orders to the foreign masters.

[1] https://www.google.com/maps/@55.3498198,11.1018692,3a,75y,26...

[2] https://web.archive.org/web/20090116051425/http://ing.dk/art...

Out of curiosity, how much is a human life worth in these calculations?

LMGTFY:

https://en.wikipedia.org/wiki/Value_of_life

United States

The following estimates have been applied to the value of life. The estimates are either for one year of additional life or for the statistical value of a single life.

    $50,000 per year of quality life (the "dialysis standard",[39] which had been a de facto international standard most private and government-run health insurance plans worldwide use to determine whether to cover a new medical procedure)[40]
    $129,000 per year of quality life (an update to the "dialysis standard")[41][40]
    $7.5 million (Federal Emergency Management Agency, Jul. 2020)[5]
    $9.1 million (Environmental Protection Agency, 2010)[42]
    $9.2 million (Department of Transportation, 2014)[43]
    $9.6 million (Department of Transportation, Aug. 2016)[44]
    $12.5 million (Department of Transportation, 2022)[45]

"We want to make the bridge safer for the users"

Seems pretty simple - sonar/lidar devices that detect dangerous ship vectors, the bridge already had gates and traffic control from some of the pictures.

Probably cheaper to do, than even the loss of one or two containers off of that container ship. Never mind the cost in human lives.

This was exactly what I was thinking, too. Systems could be set up to monitor the trajectory of objects moving around a structure and then alerting and closing bridges or tunnels.

Fucking Rocket boat...

Okay, story time. So, my brother was a law student in SF. He had a class on maritime law. They took at field trip to the Mare Island DHS office (I think) to learn more about the implementation of all the law they were learning.

So, they learned, in response to the Cosco Busan oil spill (I think), DHS decided to put in a warning system that would track all the boats in the Bay and then alert the DHS office if any of them were going to crash into Frank's Crab Shack again. Look at the trajectories, guess the time, send out an alert to the whole office. Years are spent on this system, millions of dollars, lots of studies, yadda yadda yadda.

The warning system they decided on, because this is the government and they know about lawyers, is that the whole office is going to have red flashing lights and a very loud voice come over the intra-office speakers saying 'CRASH IMMINENT". And then it'll just blare that notice until the S/W decides that the crash ain't happening anymore.

So, my brother there and they are taking the tour and the alarm goes off and ... no one does a damn thing. And he's thinking that this is really strange. And the tour guide they have looks at the group of law students and explains the above. And then the tour guide goes and says ' but they forgot about the fucking Rocket Boat'

So, in the Bay at that time, there was the Rocket Boat tour. You get on at Pier 39, you go on a tour at really high speeds, bumping your clam chowder out along the way. And to scare the tourists at the end, the pilot heads straight for Pier 39 and then turns away at just the last second. Tourists are scared, but happy, a bit wet. Everyone has a good time.

Except for the DHS office and their automated crash system. Every. Single. Time that the Rocket Boat decided to scare the tourists, the alarm system would sound.

So, since this is the government and you certainly cannot turn this millions of dollars system off now, nor can you really really be certain that the Rocket boat driver didn't actually just pass out from all the beer-only lunch he just had, the workers at the DHS office just had to endure the booming alarms and lights. Multiple times a day, nearly every day, all year long.

So, I think an automated system is a great idea. But, for the sake of all the DHS drones: Please, make the system smart enough to deal with the Rocket Boat.

Why don't they just fine the shit out of that rocket boat company every time they pull that outrageous prank? Or throw someone in jail. Who thinks that is in any an ok prank? Can you imagine someone doing that in a car? Its just a prank bro!

I mean, I'm not the lawyer, my brother is. But I'll speculate all the same.

I don't think that they are actually doing anything illegal [0]. It seems to be perfectly fine to pilot your boat anywhere you want to. Even if that means it looks like you're gonna run into the pier. It's not like they ever actually did run into the pier anyways.

Also, per other conversations with my brother, maritime law is not like 'normal' law. When we say that the US constitution is the supreme law of the land, that isn't just a turn of phrase. That literally mean 'the land'. Not the ocean. Maritime law is, from what I remember, the oldest law we have. And as such, things in maritime law aren't what you'd think.

Like, if you want to impound a boat, they have these really really comically large boat-cuffs that you have to use. And you have to do these strange legal gymnastics to actually impound a boat. Because, well, it's a boat. You can just take it over the horizon and effectively the captain will just never be seen again. It's not like the land where it's hard to get to another jurisdiction. In a boat, it's really easy. That's kinda the point of a boat.

Things like credit and ownership also work really funky too. Like, if you own the boat, but aren't actually on the boat when it goes out to sea, you're really just kinda hoping that the captain comes back. Not just due to freak storms, but also you really have to trust the captain. So things like credit and how money works on the sea are just different. Because it's so damn easy to just not come back.

If any real lawyers want to join in, please do. Again, I'm not a maritime lawyer, my brother is.

[0] To note here, the Rocket Boat company went bust in 2019, apparently. They're trying to bring it back, but seem to be struggling with the aftereffects of covid and whatnot.

What you describe sounds like international waters, close enough to the pier to matter would be within US territorial waters. So if the relevant laws are not there it is purely a domestic issue.

It seems pretty clear from the video that something like this actually happened. The only vehicles left on the bridge at the time of impact were stationary emergency services vehicles with flashing lights. So it would appear they knew it was imminent and cleared the bridge (although they underestimated the extent of the damage the impact would cause).

According to AP, the ship was able to issue a mayday and passengers of the bridge were warned: https://apnews.com/article/baltimore-bridge-collapse-53169b3...

> The operators of the ship issued a mayday call moments before the crash that took down the Francis Scott Key Bridge, enabling authorities to limit vehicle traffic on the span, Maryland’s governor said.

I don't know how long "moments" was, but presumably about as much warning as any automated system could provide.

Analysis and video: https://www.youtube.com/watch?v=qZbUXewlQDk

https://en.wikipedia.org/wiki/Francis_Scott_Key_Bridge_(Balt...

Already roughly 75 edits since the collapse.

It makes me wonder what goes through someone's head when one sees a mass casualty event like this, and your first instinct is to rush to Wikipedia to change the article to past tense ('was' a bridge).

There is a lot of misinformation in the world, and Wikipedia can often be one of the places people go to for reliable knowledge.

They probably will be getting more traffic than any single major news paper.

A lot of people, potentially scared and confused, and going to be reading that article and making decisions based on it.

Keeping the information good and complete sounds to me like a deep kindness.

Free Internet points.

But who is counting?

Other Wikipedia edit warriors.

https://imgur.com/a/g15dyXX

Do you think that someone at the FBI, inspired by https://xkcd.com/2910/, will be checking the IP addresses of the Wikipedia editors who got there before the ambulances did?

"I can't do much else, may as well keep folks up to date" I guess.

If they're sitting on the shore with a fully stocked rescue boat delaying help to post their edits, aye I'd be peeved too. Otherwise, might as well keep info updated as it becomes known.

One of the beauties of the internet is that there's enough people willing to do the work to keep the rest of the world up to date with real-time information.

Chances are changing tenses was just a single command anyway, `./pastTensify.sh "https://en.wikipedia.org/wiki/Francis_Scott_Key_Bridge_(Balt..."` or whatever the Wikipedia bot command equivalent would be.

Adding actual information about the event will naturally take a little longer as it needs writing first - they probably fired off the pastTensify automation while writing the meat and potatoes of their edit.

It was somebody on their phone, not signed in, and all they did was change "is" to "was" in two places, leaving the single word edit summary "was". But thank you for imagining Wikipedians are so professional.

Thank you for the clarification.

Not sure I understand the snarky turn at the end there but I imagine I'm just lacking whatever context you have! No problem :)

Two days later, I come back to find this downvoted a lot, even though I meant it literally. I've been a Wikipedia editor for some 10+ years, only a few of us use bots, we're not generally very sophisticated, so the assumptions amused me.

Ah. I think the wording plus the existing downvote when I read your reply made me not even consider it might be literal and not at all snarky.. I'd like to blame my British sarcasm-as-a-first-language upbringing, but really that one's on me.

For what it's worth I've popped an upvote on your comment and will go out of my way to double check snark is actually snark before replying to things in future.

Sorry for the misfiring assumption!

How do you know it was their first instinct?

"I know nothing about this bridge, let's check Wikipedia. Oh, I guess 'is a bridge' is now incorrect, I'm already here so let's change it."

What was your first instinct when you learned of the event, and how did you respond to that instinct of yours?

What was going through your head at that time?

And what are they supposed to do? Pray? Rush there to help? (from thousands of miles away potentially) They've done what they can.

Some people are clinical -just an item to update. For others it’s the old “first post” mentality. It’s basically personal mores whether something is too recent and tragic to update.

What should their first instinct be? Hop on an 8-hour flight to Baltimore, rent a car, drive to the scene and cross the cordon to help out?

What impressed me was that it looks like openstreetmap shows the bridge as down already.

https://www.openstreetmap.org/#map=16/39.2144/-76.5279

Looks up there to me [1]. If you're referring to the red colour, zoom out - all the big highways are that colour.

[1] https://imgur.com/LymzwMU

cdn cache probably,

It looked like this to me.

https://nl1.outband.net/image/fsk_bridge_down.jpg

Yes, probably tile cache on different servers. I tried from some random TOR exit node and got a mixture of tiles showing parts of the "before" and parts of the "after": https://imgur.com/zLAdmUc

Tiles are cached on many servers worldwide.

The API shows the data was modified to mark the bridge as collapsed.

Makes sense, you want anyone following GPS to divert from the scene ASAP. Caching-wise, I see the updated bridge at zoom 15+ but the old intact bridge at zoom ≤14.

OpenStreetMap editors are just as passionate as Wikipedia editors. :)

Nicer community and less bikeshedding.

https://www.openstreetmap.org/changeset/149163581

> Set access=no because the bridge collapsed

* https://www.openstreetmap.org/changeset/149163336#map=15/39....

> Bridge collapse after being stuck by container ship - https://www.independent.co.uk/news/world/americas/maryland-b...

* https://www.openstreetmap.org/changeset/149162713#map=18/39....

> Tag bridge as destroyed and ruins

* https://www.openstreetmap.org/changeset/149168397#map=14/39....

* https://www.openstreetmap.org/history#map=15/39.2182/-76.512...

Sky News was able to secure a civil engineer to give insight and analysis into this disaster in the morning hours.

It was a lightweight structure built in the spirit of minimizing cost and anticipating container ships that were approximately ¼ the mass that they are today. That giant ship smashing a critical base of support, the structure could not support itself and experienced rapid failure.

Necessary action item: Structure owners adjacent to commercially-important waterways should reassess their risks of collision by modern-sized extreme ships and mitigate where possible to preserve life-safety and sometimes property.

I see many comments talking about how shocking or rare this appears to be. In reality the maritime industry is extremely dangerous and accident prone as a result of the design of the system. Excellent book on the topic with an entire chapter dedicated to maritime: https://www.amazon.com/Normal-Accidents-Living-High-Risk-Tec...

It was hit by a container ship

https://www.nytimes.com/2024/03/26/us/ship-hits-baltimore-ke...

That's gonna be expensive.

And more importantly, distressing for the people who lost loved ones.

Alternative (registration wall, I think).

https://www.theguardian.com/us-news/live/2024/mar/26/baltimo...

No, you can click on "I'll do it later" to bypass it.

I think this is region dependent

Ah, that's a possibility I didn't take into account. I thought they were being more forthcoming than other news outlets, but didn't consider that it might be a "regional" perk.

Bypass Paywall Clean works.

>a Mass Casualty Incident has been Declared with over a Dozen Cars and many Individuals said to be in the Water.

This is literally like out of a nightmare I sometimes have, falling off of a bridge in my car into the water...

I have this one too. I'm always on a bridge that somehow has a big on/off ramp over the water and fall in off the ramp.

Ughh. This triggered the anxiety I feel when stuck in traffic on a tall bridge, like the Verrazzano bridge in NYC.

There was a video the other week on Reddit where a cargo ship devastated a few loading cranes in a port in Turkey. Now this.

How often do cargo ships run into infrastructure? Is this just a coincidence that it happened twice in a few weeks?

Yes it's a coincidence.

What else do you think it might be?

Clearly one incompetent captain keeps getting reassigned across the world.

Cargo ships have done serious damage to infrastructure in the last few years. The giant ship stuck in the Suez was just an example - giant ships have gotten stuck in the Chesapeake Bay, Rotterdam and elsewhere.

The same week for major disasters would be a coincidence but I'd guess minor stuff is happening constantly.

The main thing is that shipping companies have been taking advantage of the way maritime law limits their liability for their behavior by scrimping on maintenance as well as using ships essentially too large for the waterways they travel in.

No it's not a coincidence, these incidents are a result of the design of the system. Excellent book on the topic with an entire chapter related to maritime safety (or lack thereof): https://www.amazon.com/Normal-Accidents-Living-High-Risk-Tec...

This is going to have a huge impact on traffic patterns in the mid Atlantic. The bridge carries 695 (the Baltimore beltway) across the river. Although I95 goes through Baltimore, 695 is one of two major bypass routes that’s a more direct shot from places south of the city to places north of the city (the other being the Baltimore harbor tunnel carrying 895). Unlike the Philadelphia bridge span collapse recently, I don’t foresee this bridge being rebuilt anytime soon.

> Unlike the Philadelphia bridge span collapse recently, I don’t foresee this bridge being rebuilt anytime soon.

How come?

In Philly, they sacrificed some of the road underneath it and narrowed the traffic lanes over the bridge to enable a very quick, albeit temporary repair. There’s no such option for a span of this length over a river — this is a decade long project that could potentially be sped up to be a years long one.

Sure, 5-10 years makes sense especially considering it took 5 years to build last time. But GP's formulation seemed to suggest a considerably longer expectation, and that's more what I was wondering about.

I took it to mean considerably longer in relation to the bridge in Philly -- which of course it will be since that overpass reopened in ~2 weeks.

I would be shocked if it was rebuilt in less than a decade. The Frederick Douglass bridge that opened recently in DC took 15 years. That’s a long time for Baltimore to be without a key piece of infrastructure.

Could this be cyber attack? On the video the ship goes normally straight under the bridge, then does sharp turn right and for 20s or so goes directly into the pier.

Anything's possible, but a ship losing steering control is not that uncommon.

This just happened at a particularly bad time and place.

It looks like the nominal trajectory takes it very close to the pylon. Why wouldn't nominal be towards the middle of the two pylons?

Then things like collisions and tug accidents would be more common, which are a far more realistic risk. Remember, there is 2 way traffic.

The ship loses power before the turn. The power loss could of course have been the result of a cyber attack, but a mundane mechanical failure seems more likely.

The speculation on hacker news vs reality is interesting to note. Don't guess before the facts are out.

https://www.nationalreview.com/news/major-baltimore-bridge-c...

> The container shipper that caused the collapse of a major bridge in Baltimore early Tuesday morning issued a Mayday call indicating that it had lost power shortly before it struck the bridge’s piling, allowing state officials to close the bridge to traffic in a move that likely saved lives, Baltimore mayor Brandon Scott said at a press conference held as search-and-rescue efforts continued.

Yes, they have traffic control on the bridge, and they stopped traffic when they got the mayday.

Was anyone driving across? I didn't notice car headlights on the bridge, but...

edit:

The guardian clip says vehicles were on the bridge.

I'm reading here on local news there were multiple construction vehicles on the bridge when it collapsed.

You can see the construction vehicles on the bridge on te right of the container ship, they are standing still and are running flashing lights. And they go down into the river ...

I saw a few Semi Trucks pass over it about a minute before the collision and collapse. There were construction vehicles on the bridge, with flashing lights.

You can clearly see headlights moving across it as it comes down.

https://www.reuters.com/world/us/16-mile-bridge-baltimore-co...

Didn’t waterway authorities (in the U.S.) used to require tugs to navigate large ships under bridges?

I thought that they had a pilot board and navigate into port, but I only know of anecdotes.

We'll be hearing a lot more about this. It's a really major accident.

I used to live in Bawldamer, in the early 1980s. Back then, it was a tough, blue-collar city, but not yet The Wire.

Especially if this ship had power issues, as seems to be the case.

Tugs to navigate would have prevented this incident.

This container ship ran out of power twice and lost navigational control, which resulted in loss of life and billions in civilian infrastructure.

Seems one cannot rely on container ships alone to navigate narrow passages safely.

No, tugs stop escorting the ship when it enters a main navigation lane. It is very dangerous to move at those higher speeds while attached to tugs. Look up 'tugboat girding' if you want to learn about it.

Looking at the video of the collapse, it looks so unreal and... cartoony? Like my brain refuses to comprehend that this happened to an actual metal bridge, like one with cars and trucks on it.

small blessing it happened late at night, so hopefully the casualty numbers are low...

Tom Scott video on container ship training

https://youtube.com/watch?v=jplrbxI5GN8&pp=ygUYc2hpcCB0cmFpb...

Let’s say you had infinite money and no paperwork filings required. What is the fastest possible timeline in which a replacement bridge could be designed and completed?

Just removing the detritus of the current bridge sounds like a multi month affair.

I'd think that a place like an international shipping port would have equipment in relatively close proximity for handling (albeit much smaller) tasks like wreckage removal and the like.

I have no idea what a practical timeline would be, but I think it's fair to say that it's less than your average 1.6 mile bridge.

It probably won't take long to cut a hole in the wreckage to at least get one sea lane open so the port can still operate. A bunch of folks with metal cutting torches on a few dozen boats and a floating crane?

https://www.google.com/maps/place/Francis+Scott+Key+Bridge,+...

https://apnews.com/article/baltimore-bridge-collapse-53169b3...

BBC liveblog: https://www.bbc.com/news/live/world-us-canada-68663071

Grady's licking his lips right now

For those who want to hear up to date news, some local sites are:

WBAL https://wbal.com/ WTOP https://wtop.com/

Two local news radio stations. Fans of The Wire series may have heard WBAL in the background in some of the scenes, it's a Baltimore institution since everyone wants to get traffic updates.

TRAFFIC AND WEATHER ON THE 8's AND WHEN IT BREAKS!

WBAL and WTOP has been a great service to cover the great disarray of Baltimore over the last decade.

"when it breaks" indeed...

WTOP was how I found out on morning commute, though thankfully I work inside the DC beltway rather than the Baltimore beltway.

Does anybody keep track how often these ships lose all power?

Wasn't that long ago that another massive cargo ship lost power in the Suez, crashed and blocked that channel for a while.

Somehow I'd expect that there would be backup systems keeping basic rudder control going even in a total power failure, but clearly that isn't the case.

The Ever Given didn't lose power, it was just a very big ship trying to navigate through a very small, shallow channel and was hit by strong enough winds to knock it off course.

How long until Elon offers to dig a new tunnel under the Patapsco river? I bet he already has Boring people on it.

He wouldn't be interested. He has a car company so he's only interested in sabotaging public transport.

And accuses any critics of being paedophiles.

He can offer all he wants, the answer is no. Though when you live the life of a billionaire, you're so used to getting appeased that you probably don't understand what "no" means when it's applied to yourself.

The Association of Maryland (boat) Pilots literally has a header image of a harbor pilot tug escorting a cargo ship to the Key Bridge...

https://www.mdpilots.com/

Wonder where they were.

On the bridge of the ship one would imagine.

Looks like they were on the ship, should there also be a tug when piloting these ships?

https://www.dailymail.co.uk/news/article-13239953/Singaporea...

>The cargo ship that smashed into the Scott Key Bridge in Baltimore overnight was piloted by a specialized crew trained to avoid obstacles at ports, it has been revealed.

>The ship, a 948-foot-long DALI operated by Singaporean company Synergy Group, collided with the 1.2-mile bridge shortly after 1.26am as it left port.

>Maryland Transportation Secretary Paul Wiedefeld said on Tuesday morning it appears none of the 22 crewmembers were injured, as he revealed it was being steered by the specialist pilots.

>'Pilots move ships in and out of the Port of Baltimore,' he said at a press conference, noting that the specialist pilots depart the ships as soon as they are in open water.

More details froem WaPo...

>The ship was towed into the river initially, but the tugboats did not accompany the ship all the way to the bridge, said John Konrad, a retired ship captain who runs the gCaptain maritime news website and co-authored a book on the Deepwater Horizon oil spill.

>“The safe thing to do is keep the tugs,” Konrad said. “Moving forward, I think that’s going to happen. The Coast Guard is going to say you’ve got to keep the tugs tied up until you pass the bridge.”

Keeping the tugs is not safe, and it is normal for them to leave when you enter a main navigation lane. At high speeds, tugboats can get capsized due to girding. It kills mariners, and the practice should not be introduced because of a single extraordinary accident.

Here is real time playback of the incident, you can see both tugs leave the ship and do not accompany it past the bridge. You can see one of the tugs turn and head back to the ship before the collision...

https://twitter.com/MarineTraffic/status/1772545501612671284

I never realized how ambiguously generous the term “Search & Rescue” was.

A similar incident happened about a week ago in Turkey: https://youtu.be/YDOMhCCpTnQ?si=ebghOqwVUzmmMIrd

https://ibb.co/BrYQhQJ

Looks like normal operations after departing container berth. Concerning is the speed ramping up.

Insane that the pylons wasn't protected by artificial islands.

I tend to agree, but also, what could one even do? I have seen videos of shipping containers going into the shore and they don't stop for a good hundred yards or more.

I don't know how they achieve it, but its best practise to protect bearing elements from collisions like this. There's like a whole subfield of bridge collision research.

If you think about this for a minute, you'll realize that what you're asking for is pretty much impossible.

What would these artificial islands be made of? Sand, gravel, concrete rubble? This is a river, the constant current of the water erodes anything that resists it by staying in place. Piling up enough material to resist erosion and create a meaningful obstacle to 70000 tonnes in motion, that would significantly narrow and make shallow the navigable waterway. The only way to do this is to build giant underwater concrete towers -- basically the structures pylons typically rest on, the piers. Look up the process required to build these, it's quite an undertaking. They are engineered to withstand the pressure of ice floes every spring, they're not flimsy by any measure.

I have thought about it for hours by now, and read literature on the matter. It is definitely possible to build berms that protects a bridge from catastrophic failure in case of a ship collision, and it is widely done during modern bridge construction. Please be less sure of yourself when you clearly don't have any actual knowledge on the subject.

I'd love to see a few examples, since you're so versed on the subject. I'm not a civil engineer by any means, but I imagine the people who designed and built that bridge knew what they were doing. There are likely limitations imposed by the site bathymetry and other things we don't know about.

You can get a good look at the aftermath here: https://www.youtube.com/watch?v=WssFXRzRVLU

I'll be interesting to see how they choose to rebuild it.

There are real world examples of what it would look like, they're called "dolphins": https://en.wikipedia.org/wiki/Dolphin_(structure)#/media/Fil...

"The new bridge is protected by 36 dolphins: four large dolphins protecting the two main pylons supporting the cable-stayed main span plus 32 smaller dolphins protecting bridge piers for 1⁄4 mi (1⁄2 km) to either side of the main span"

See my response to the other copy of your comment above

"I have thought about it for hours by now, and read literature on the matter." Ah, the classic, pompous Hacker News user. The Baltimore Port Authority should've hired you to prevent this disaster - you're a genius!

Seriously, this comment has to be satire.

There are real world examples of what it would look like, they're called "dolphins": https://en.wikipedia.org/wiki/Dolphin_(structure)#/media/Fil...

Dolphins seem to be just pilings tied together.. how could those withstand the impact of a loaded container ship?

For something a bit more sturdy, look at the main pylons of the Jacques Cartier bridge in Montreal [1] - these are meant to withstand annual ice rush, hundreds of tons of ice floe moving with the current of the river.

Interestingly, while the Saint Lawrence is a very active shipping channel, most shipping near the city moves through the seaway canal [2], which has solid earthen berms reinforced with concrete wherever it crosses a bridge span [3], [4] making it next to impossible for this type of accident to occur.

If memory serves right, the seaway was built to avoid the strong currents and wild rapids of the river; there are a set of locks [5] upriver, and the engineering around bridge crossings [6] seems consistent as you trace its path

1: https://www.google.com/maps/@45.5198582,-73.5385996,94a,35y,...

2: https://www.google.com/maps/@45.5237446,-73.5262812,90a,35y,...

3: https://www.google.com/maps/@45.4986758,-73.5188312,123a,35y...

4: https://www.google.com/maps/@45.4717554,-73.5051917,148a,35y...

5: https://www.google.com/maps/@45.4080264,-73.5557603,298a,35y...

6: https://www.google.com/maps/@45.4082771,-73.6528304,266a,35y...

https://www.washingtonpost.com/dc-md-va/2024/03/26/how-key-b... There are some, but because the ship drifted in at an angle, it missed them.

It was, each pylon had 2 dolphins. Idk why people on the news keep saying it wasn't. Its hard to imagine being invited to speak on the news and not bothering to check any of your facts.

source: https://www.youtube.com/watch?v=CwgOHpZlxvc You can clearly see there are channel barriers, its just the ship came in at an angle.

Worst possible time to have a technical issue. Feel bad for the crew, they couldn’t do anything in this situation.

Does anyone have any theories what could have gone wrong technically?

Every bridge with large cargo ship traffic beneath them should have channels designed to guide the commercial traffic, installed beneath them. Every city with bridges like these should, with state AND federal funding, should begin the process of constructing such "guidance channels" beneath these bridges IMMEDIATELY!!! It should be IMPOSSIBLE for Ships large enough to damage bridges to even be able to come into contact with these bridges. The idea that the ship itself has 100% control as to whether it strikes a bridge or not, IS INSANE.

The problem is momentum. These ships weigh thousands of tons so something as simple as coming to a stop is difficult. The ship probably knew it would collide with the bridge well in advance but had no way stop of avert the ship due to it's sheer size.

Doesn't have to stop them, just has to redirect them

What you are proposing isn't feasible from an engineering perspective. This isn't like putting a guard rail up.

To make damage from collisions "impossible" you'd have to build embankments up so high that the bridge would effectively be sitting on solid ground the entire way across and no ships could pass anywhere.

Sure, there are ways to mitigate collisions and the new bridge they build will no doubt be more resilient, but it's not realistic to completely eliminate such risk.

How about instead of adding "bumpers," it becomes required for a tug boat to help guide past infrastructure spans like bridges, rail, gas.

There is already something like this in use: harbor pilots, who have specialized knowledge of specific ports and board vessels to navigate them through critical transit zones. It is reported that there were pilots on board navigating at the time of the collision.

Tugs are used in tight locations, but they can only change a ship's speed at a very slow rate compared to that ship's engines. By analogy, you can pull a train car and get it moving by yourself, but if that thing is moving at 5mph you aren't stopping it by yourself in any reasonable distance.

I feel that in this situation a nearby tug boat could have diverted the ship (by at least kept it from straying from the shipping channel during power failure).

I think you're probably right. A tug (or two) hypothetically could've provided some emergency directional control.

When they reopen the port, it'll be interesting to see what early mitigations they put in place.

How long did this event last from start to finish? Just wondering why there are cars still driving through the bridge moments before impact.

Supposedly the ship issued a mayday prior to losing power and hitting the bridge, so they were able to stop traffic and limit the number of people on the bridge during the accident. Most of the people who went down with it were construction workers.

It was something like 4 minutes.

A lot of these ships are controlled via GPS to keep them in the channels. I wonder if this crash will entail a software bug or system failure.

This ship was under pilotage at the time.

In the same way that airline captains don't sleep during takeoff or landing, the captain is in the bridge (and with the assistance of a harbor-specific pilot) for the entirety of maneuvering in and out of a harbor.

Yeah, but they're usually relying on GPS, especially at night, even if they are at the controls. The controls are drive by wire anyways, even if they aren't using GPS plots.

Lack of redundancy. Also a major contributing factor in the 737 MAX crashes. Redundancy is a low price to pay for peace of mind.

The problem is that it is a price to pay. When efficiency, savings, and profits is the imperative, the cost savings is "worth" the billion-dollar disaster... right up until it happens.

Very, very few bridges have redundant support structures. Also the 737 MAX is a case of how redundancy DOESN'T always solve issues

The crashes were a result of a single sensor being a point of failure. The update uses two sensors and they must agree with one another.

Seems like wbaltv.com has some geo restrictions... "Sorry, this content is not available in your region."

Apparently there were two different key bridges, one across the Potomac, another across the Patapsco. This was the Patapsco one.

The other key bridge is not in Baltimore.

Yeah the original cnbc article was talking about the Potomac which isn’t near Baltimore, so I wanted to make sure no one else was as confused as I had been.

The Potomac River is pretty shallow where the Key Bridge crosses between the Georgetown neighborhood of Washington, DC, and Rosslyn neighborhood of Arlington County, Virginia. The largest facilities upstream of it are boathouses, where one may put in a canoe or perhaps a racing shell.

Is it feasible to run large ships on autopilot? Large airliners land mostly on autopilot now, right?

Seems like a somewhat solvable problem to combine a bunch of sensor inputs to keep the ship inside of a safe corridor, such that even a loss of power would be accounted for to ensure it would drift safely.

Is it a much harder problem than my intuition assumes? Cost issue?

The early reports suggest that the ship was having trouble actively maintaining position - some have theorized a stuck rudder or wind pressure – in which case the only thing an autopilot could do is make the situation worse. I’d wait for the full investigation to come out before speculating about fixes.

Not a fix per se, but a safer system going forward.

Given all the variables, is it feasible to build a system that continuously runs through multiple failure modes, predicts where the ship would end up and then guide the ship on a course where even a loss of power would have the ship drift between the supports.

Was there a configuration of the ship that would have prevented it from hitting the bridge even after the power loss.

This seems like something that could be continuously calculated in realtime to keep a ship in a safe corridor, such that it wouldn’t strike the bridge even if the engines failed, based on winds, currents, size, load, etc.

I’m speculating about fixes, because it seems prudent to think about how to prevent the next strike before it happens. I feel like technology could reduce that risk to some degree.

I think that in general, a course that (a) gets the ship from where it started to where it needs to go and (b) stays within navigation channels and (c) minimizes the amount of time spent in configurations where a loss of control would result in a collision will spend a nonzero amount of time in such configurations.

> guide the ship on a course where even a loss of power would have the ship drift between the supports.

If one of the failure modes is a stuck rudder, how’s that supposed to work in a narrow space where it could be drifting in either direction?

Welp, someone at a maritime insurance company is having a bad day.

It took 5 years to build in the 1970s. It took 5 seconds to destroy

let's see how long will it take to build today

"We can’t, we don’t know how to do it"

Pittsburgh built the replacement for the collapsed Fern Hollow Bridge in less than 8 months. The one that collapsed took 14 months to build.

https://en.wikipedia.org/wiki/Fern_Hollow_Bridge

See https://mdta.maryland.gov/Toll_Facilities/FSK.html

I hope they rebuild it in a similar design. It was beautiful!

The footage looks absolutely crazy - I hope people are safe.

Judging by the footage with the bridge being over water and the temperature in Baltimore near freezing, I would guess no they are not. The outcome of this is going to be very unpleasant.

"Luckily" this was not during rush-hour..

Unluckily it was at night, so an already disorienting situation is going to be harder and any already difficult rescue is going to be hampered further. It will be a miracle if any meaningful % of those who fell in the water survived.

Fransje26 has a point. If this had been during rush hour the numbers would be 20x what they are right now.

Of course it’s still tragic and awful.

I just watched the footage. It's pretty horrifying. The whole bridge collapsed in a few seconds. It's a pretty long drop down to the water. Anyone on that bridge ended up in the water with little/no warning.

That drop alone would injure/kill many. And immediately after people would be in cold water still locked in their vehicles. The water there was deep enough to be able to deal with loaded container ships. So, tens of meters at least. If you then factor in currents and the amount of time it takes to mount any form of rescue operation with divers, etc. it starts looking pretty grim indeed.

I hope rescue workers pull off a minor miracle.

from what I can tell it didn't look like vehicles, it looked like road maintenance, so people outside and maybe a vehicle. only difference is not trapped in vehicle, everything else still dire

There's a slight benefit that a road crew will be dressed for nighttime outside weather, with reflective clothing, are all adults, and probably have some level of physical fitness.

If you're going to be dropped into water, heavy clothing is probably very much not what you want.

Thick winter clothing is what you want if you have something to hold on to which floats. Otherwise it's a choice between drowning and hypothermia...

> The water there was deep enough to be able to deal with loaded container ships. So, tens of meters at least.

There are only a handful of ships in the world with a draft of more than 20 meters. The ship involved in the collision has a (maximum) draft of 15 meters.

Doesn't really matter. You can drown in 1 meter.

Looking at the video there was little traffic at just that minute ... but sadly it does look like there was a road crew up there

How is the thread only an hour old but comments 9?

Mods probably merged multiple posts.

TIL that these ships stay at sea for months.

Didn’t they (the waterway authorities in the U.S.) used to require tugs to navigate ships under bridges?

Holy shit. Such things should never happen.

> Sorry, this content is not available in your region.

Mkay then, gdpr is too much for some to accept I guess. Anybody got any mirror link?

The first thing that popped into my head when I mis-read the title as "Francis Scot Key Board"

https://i.imgur.com/w9foiSB.jpg

Oh, this makes me feel bad for Baltimore. Only bad news seem to come out of this town. Its reputation -- both domestically and internationally -- is mostly informed by The Wire, Freddie Gray/BLM, a dysfunctional city government, the 2019 ransomeware attack, the spoiled batch of J&J Covid vaccine... and now this. It's a real shame. It's a good place.

John Waters on Baltimore:

https://www.theguardian.com/travel/2014/nov/28/john-waters-b...

John Waters’ Baltimore:

https://baltimore.org/what-to-do/john-waters-baltimore/

Weirdly I think Baltimore is thriving. It just really doesn't advertise itself.

Hopkins is huge.

We’ve also got cherry blossoms, some good ramen and a few good breweries. Shocking lack of excellent Mexican food, however. And some world-class hospitals and universities. Don’t take TV shows so seriously.

Not a ton of Mexican food, but if you're open to other Central or South American cuisines, there are a ton of places in upper Fells Point.

Please do yourselves a favor if you haven't already and check out the tacos at Taqueria el Sabor del Parque on the south side of Patterson Park. Also while you're in the area, grab a kilo of tortillas from El Taquito Mexicano in Fells.

BMore Taqueria in Fells Point is pretty good.

https://www.bmoretaqueria.com

We’re fine, thanks.

Interesting use of the passive voice. Wasn't it clear from the start that it was hit by a ship?

"Has collapsed" isn't passive voice; it's a compound past tense.

Compound past perfect, specifically

The power outages make me think it's a terrorist attack meticoulously planned via a virus. I hope we will get answers soon

I would be very interested in knowing who was piloting the ship. And I hope they are held criminally accountable for their actions.

What do you do with a drunken sailor, What do you do with a drunken sailor, What do you do with a drunken sailor, Early in the morning?

Video here https://twitter.com/sentdefender/status/1772514015790477667

While this tweet is factual, be very careful with this account in general, is has turned from a good source to a very slanted and biased fake-news-accelerator.

Have any examples of fake news from that source we should be careful about?

What was the ship captain's plan here? Just ram through the bridge?

Appeared disabled in the video, this was not planned.

The captain was disabled or the bridge? I dont understand how you set a course through a bridge like that

A course is set through the middle, side thrusters, rudders, and|or engines fail or falter, and current drifts the ship into the bridge pylon.

Ships in water tend to move and keep moving, engines and thrusters work to vector that motion into a desired direction - when things fail motion doesn't cease and courses aren't maintained.

The best quote from Mass Effect:

Sir Isaac Newton is the deadliest son-of-a-bitch in space!

Gravity is a harsh mistress..

"this hurts you, Shephard"

https://imgur.com/a/OXDh1mM

Here’s an image of its path

The lights on the ship all go out about 5 minutes before impact. They come back on and appear to go out again as impact gets closer. It looks like the ship suffered a catastrophic failure that affected the controls.

The ship, most of its lights go out a minute of two before the collision, and it also seems to be emitting black smoke (from the funnels / engine exhaust?) as well.

Looks like the captain might have had little control and/or been distracted, what with the ship being on fire at the time.

It looks like it's smoking nicely, yes..

The smoke was likely from the engines running at full reverse to avoid the collision. But the ship lost power (you can see its lights going out in the video) and thus the ability to steer.

Usually, a harbor pilot guides the vessel when entering and leaving the harbor.

The pilot is a former captain with a lot of local experience.

https://en.wikipedia.org/wiki/Maritime_pilot

[Edit: The association of Maryland Pilots even has the bridge on their homepage https://www.mdpilots.com/]

Did the pilot screw up? Was the pilot ignore? Did the captain take over? Was there a technical fault that disabled steering?

There could be a lot of possible reasons for this incident.

It's clearly visible in the video that the ship loses power twice before the collision.

That could be an effect of aggressive attempts to regain control rather than the cause, though.

In most cases the pilot is there as an advisor, the captain/master is still in command of the ship.

BUILD CHANNELS UNDER THESE BRIDGES!!! By digging out channels beneath BRIDGES that have large cargo ship traffic beneath them, these ships would run around, and/or hit a wall (depending on design) before ever getting close to bridges structural support components. Every city with bridges like these, with city, state AND federal funding, should begin construction on "guidance channels " IMMEDIATELY...

You good dude?

Francis Scott Key wrote the Star-Spangled Banner, which later became the US national anthem, while gazing across this same Patapsco river in the morning after a battle and saw that the flag was "still there". On the morning of March 26, 2024, the Bridge in his name was no longer there. Sad.

The bridge stood for 47 years and 3 days (17170 days) before destroyed by a trade ship from Asia headed for Indian waters. The tragedy occured when the engine of the tradeship failed resulting in it being adrift until colliding with the bridge.

The Key bridge collapsed 209 years after its namesake wrote the Star-Spangled Banner. The embarrassed tradeship had been christened Dali: a name famous from the Spanish surrealist painter known for depicting melting clocks, not bridges.

LLM for Poetic writing?

Hahm. No, I did it myself. Your LLM detection circuitry needs to be upgraded, sir.

It's sad that people think anything a little 'different' is LLM. Almost exactly as if those takes like "this is LLM" is an LLM-brained take itself haha! :)

Also important to note.

The logistic company running this ship was Maersk. That is the same shipping company that had the ever given stuck in the suez canal a few years ago.

Is Maersk now officially the "Boeing" of shipping?

They are in terms of "most large planes are Boeing so you'll hear about their accidents most often", no idea if also in terms of "terrible safety culture so there'll be an unacceptable rate of accidents".

What? No it wasn't.

https://en.wikipedia.org/wiki/MV_Dali_(2015)

Mærsk chartered the ship, according to the Guardian.

No, Ever Given was not a Maersk ship https://en.wikipedia.org/wiki/Ever_Given

No, with the top reason as to why not being that Maersk did not construct the ship.

Saying that Maersk is at blame is like blaming the airline instead of Boeing.. if you want to make that parallel.

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