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Comment by paddy_m | Hacker News Reader

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.

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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.

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.

  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).

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

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

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.

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

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

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

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.

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