A chain cuts through a capsized cargo ship filled with cars
jalopnik.com
jalopnik.com
Historically torpedoes used to hit the sides of ships, punching big holes. The response by ship builders was to build empty “torpedo bulges” on the sides of ships to trigger the torpedo early, preventing structural damage.
Modern torpedoes instead detonate under the ship. The explosion creates a massive bubble (most explosives being nothing more than a solid that’s itching to turn into a hot cloud of nitrogen). This bubble ends up under the ship, resulting in a ship that’s supported at the ends and not the middle. It turns out modern ships aren’t strong enough to support their own weight in this way, and the ship breaks in two.
Obviously this lacks the grinding mechanism described here, but the similarity is in the application of a huge amount of force in the middle of a ship to break it.
This has no relation to a torpedo at all except that the localized mechanical force exceeds what the material can handle. But that's how every, cutting bending shearing, swaging, grinding, etc, etc operation works.
I actually found the comparison fairly helpful.
It isn't just being forced to support its own weight by a bubble that sinks ships... it's the force applied in the direction it's applied by the explosion of the torpedo. Most hulls aren't designed to handle a sudden non uniform upward moving force in their middle accompanied by a shock wave.
I wish the article had more information about the chain itself. I've seen this done with diamond cutters on wire rope (like used for the Kursk) but not with chain. From the look of it, the chain has the outside of the links coated with abrasive?
Perhaps instead of saying 'This related to, but not the same as' the commenter could have just said 'this reminds me of'.
Very few people need to know this or will use the info and if they do they wouldn't rely on an HN comment just reading out of curiosity.
But that isn't what they are doing. This isn't cracking the ship into halves. This is very slowly grinding a hole through the structure. Look to the edges of the cut line and you will see the failure mode of the metal is very different. No sharp/jagged fractures, more round peeling off of metal. It is the difference between using an axe and using a saw.
(1) The weight of the ship acts against the explosion increasing the initial stress
(2) The gas bubble created can vent straight up on a side explosion. Under the keel means it has to go through/around the ship increasing the stress.
(3) Since the explosion lifts the ship you're going to get significant additional damage when it crashes back down into the water.
(4) Like (2) as the gas bubble disperses water rushes back into the vacuum. All of this water coming back in will collide in the middle resulting in a geyser going straight up into the ship.
Thinking about it is you detonate an explosive under a boat it's going to create a shock wave that will hit the boat like a hammer and probably do a fair bit of damage to the hull before maybe the support at the ends thing happens.
> “Approximately 25 hours into the cut, the cutting chain broke,” St. Simons Incident Response writes on its website.
Instead, with a chain they just replace a couple of broken links and back on track. Which is apparently what they've done:
> Unfortunately, the chain actually broke during the cutting operation. “Approximately 25 hours into the cut, the cutting chain broke,” St. Simons Incident Response writes on its website. Luckily, there were no injuries and there was no damage to the equipment. The team simply fixed the chain’s broken link, inspected the other links for signs of fatigue, and continued on.
IIUC, it's much less dangerous to be around a breaking chain than a snapping cable.
When the Kursk was raised they first cut it in half using an abrasive chain/cable. In that instance it was pressed down from above the structure.
"A cutting chain made of abrasive covered bushes on a thick steel wire was pulled back and forth across the hull by the cylinders. Vertical forces were supplied by the controllable vertical position of the suction piles."
https://www.maritimejournal.com/news101/tugs,-towing-and-sal...
It reminds me of a Fermi estimate that my physics professor presented of how tall the tallest mountain on Earth or a generic planet of mass M could be. He started with the intuition that when the weight of a mountain overcomes the typical strength of chemical bonds, what we typically experience as “solid” rock will behave like a liquid and collapse.
By maritime standards that chain is tiny, akin to a thin wire cutting through cheese.
https://www.reddit.com/r/interestingasfuck/comments/6wvvkj/a...
https://www.usni.org/magazines/naval-history-magazine/2017/d...
The gear used in these large scale engineering ops is absolutely remarkable, it makes me wish I had a better understanding of our physical world.
At the time it was all in one piece, but you could see them attaching the lifting equipment along the length, and it was clear it was going to be cut into pieces.
It must take an enormous amount of work to build an internal framework that can support the cut section being lifted from the side. I’m not surprised it’s taking so long so salvage.
Ships have to be able to withstand substantial side forces (in both tension and compression) as part of torsional loading in normal operation. There's no internal framework needed. Even if there was that would require a stupid amount of effort compared to just adding more lifting points.
It's stupid easy to figure out lifting solution in this case because this is a new enough ship that CAD models exist. If the owner doesn't have the CAD files you pay whoever you need to to get them (you just need a low detail model of the hull and bulkheads, not the high detail models that include plumbing and whatnot, those would be needlessly expensive), then import the models and then run numbers until you get numbers you like (e.g. section sizes the crane guys won't complain about and a safety factor corporate won't complain about). Then you tell the intern to use the CAD models to whip up a set of matching plates for lifting. If they have extra time on their hands maybe they'll make some random feature dong-shaped. Then you forward that attachment to the sales guy at the steel supplier you usually use.
All this stuff is routine business for the parties involved.
Investigators concluded that the underlying problem was a lack of proper communication between Jack D. Gillum and Associates and Havens Steel. In particular, the drawings prepared by Gillum and Associates were only preliminary sketches, but Havens Steel interpreted them as finalized drawings. Gillum and Associates failed to review the initial design thoroughly and engineer Daniel M. Duncan accepted Havens Steel's proposed plan via a phone call without performing necessary calculations or viewing sketches that would have revealed its serious intrinsic flaws—in particular, doubling the load on the fourth-floor beams.
-- https://en.wikipedia.org/wiki/Hyatt_Regency_walkway_collapse
Years ago, I was a computer science major at Tulane University. At the time, Tulane put CS in the school of engineering, so every first year had to take a mandatory engineering safety class. The first day of class, they turned off the lights and played a home movie that was recorded during the dance at the Hyatt-Regecy. The video cuts out right before the disaster, but there is audio from one of the musicians, and they played that.
Sitting in a dark room listening to a huge crash followed by screams of pain and terror fully instilled the importance of engineering safety in me. This was 20 years ago and I still remember it clearly.
Often I wish everyone had some mandatory class like that to teach them the seriousness of the consequences of our actions.
("[T]hat jet liner that kept falling apart because of the square corners in the hatch" is the DeHavilland Comet, BTW.)
Mazda in 2008:
It all started about two years ago, when a ship carrying 4,703 shiny new Mazdas nearly sank in the Pacific.... The mishap created a dilemma: What to do with the cars? They had remained safely strapped down throughout the ordeal -- but no one knew for sure what damage, if any, might be caused by dangling cars at such a steep angle for so long.... The Japanese car maker, controlled by Ford Motor Corp. , easily could have found takers for the vehicles ... [but] Mazda turned everyone away. It worried about getting sued someday if, say, an air-bag failed to fire properly due to overexposure to salty sea air.... So it decided to destroy approximately $100 million worth of factory-new automobiles.
https://archive.fo/5Peq8 (WSJ)
I did see they are building a temporary recycling center for when they remove the vehicles.
Those are all probably 2019 or 2020 models, so the salvaged parts could be worth some decent money.
It's less "cutting" and more "crunching" its way through. Sheer brute force plastic deformation.
On the other hand, since oceangoing ships are (mostly) regulated by the countries they're registered in, which is frequently a regulation-light jurisdiction like Panama, Liberia, or the Marshall Islands - there are a surprising number of situations where the owner of the ship just completely disappears and the ship is left to rot.
One of the most famous recent examples of this was the ship involved in the Beirut port explosion this year. After being impounded for being unseaworthy, it rotted at its moorings and eventually capsized in the Beirut harbor.
A quick trip through developing-country ports on Google Earth will have quite a few ships like this.
That's is why only few cruise ship start and end their trips in the USA.
[0]: https://en.wikipedia.org/wiki/Compact_of_Free_Association
For instance, the ship could have carried cars made at the Kia and Hyundai plants in Mexico to the US, and also loaded cars made at the plants in Georgia and Alabama for delivery to the Middle East.
It's not at all unusual for the cargo to cost far more than the ship that's carrying it.
Kinda like S3 is "a very large static file host", it is technically true but the scale involved makes everything a lot more involved.
When it's the right way up, industrial diesel powered pumps could pump it out enough to float and reuse.
Perhaps there were political reasons? (ie. if the ship is refloated, the original owner would own it, whereas if its scrapped the port authority can take the collected 'litter' as payment for the work)
Refloating was already tried a few times and failed
>PCTC Golden Ray was partially capsized in St. Simons Sound, Georgia, when the pilot deliberately grounded the 20,000-dwt ship in response to a fire on board on 8 September. It was sailing out with 4,200 vehicles on board and was grounded on a soft seabed.
>Attempts to refloat the vessel have so far failed and the US Unified Command handling the salvage has decided to disassemble the ship in situ. It believes attempting to right and refloat this ship would not be technically feasible.
Also, from the first image in the picture you can see that the cargo has shifted and is now all on the side of the ship . Modern cargo vessels don't have that much excess stability, so chances are that it would not stay upright even if it were completely pumped full of air.
But they probably already thought about that and I just missed it in my rapid skimming of the article.
https://en.wikipedia.org/wiki/MV_Tricolor
Video documentary:
On iPhone, no.
https://adblockplus.org/blog/adblock-plus-for-ios-9-finally-...
The ridges and valleys on a chain effectively are the teeth of a saw.
Plus, the cost for cleanup for this kind of disaster is built into the price of each car/phone in the form of shipping costs, which include insurance costs. So while they contributed to the damage, they also contributed to the cleanup.
Oil tanker spills are typically in the range of tens to hundreds of thousands of tonnes of oil.
So, don't waste cycles worrying about it; it's a rounding error in the general scheme of things.
I realize it's still likely a drop in the proverbial bucket. :(
Each image takes a few seconds to load, and if I scroll too far then the images no longer load. It seems that no image will load until the previous image has loaded, and only images currently at the scroll position will load, so I cannot just scroll to the bottom of the page and let it all load. This is on Firefox 83 / Ubuntu.
Literally every picture in the 'article' was paired with an ad. How tf is anyone supposed to concentrate on what they are reading with constant interruptions?
Even with the ads just being blank spots it drove me so nuts I added jalopnik.com to my blacklist.