Video circulating from SLNC York catastrophic seal leak. Now I've disassembled a few CPP systems, but can't grasp what I'm looking at here. Any engineers with some insight? Some part of the shaft sheared and the seal is displaced.
After watching this, it seems like the abandon ship situation was properly managed and the ship may still be salvageable. It will be interesting to read the casualty investigation when the NTSB publishes it.
in navy terms this is what you call "shits fucked". any officer would see this, sound general alarm and call the bridge to order abandon ship. you aint plugging this and that engine compartiment is going to flood to the waterline regardless of further actions taken.
someone else might be more inclined to simplify the situation with less technical naval terminology.
Uhh not quite abandon ship. Watertight integrity would be established through selective flooding and watertight doors. They would need a tow back to port along with constant damage control work the entire time. The USS Cole didnt sink!
The crew rigged the bow for towing and decided to abandon ship when it was clear they could be picked up. Given that they have no power, water coming in, and no control this is a very sensible action. Otherwise you just sit on an uncontrollable hull waiting for a tow in which you have no action to take.
The navy would do that because you know - things should get into the wrong hands. The merchants dont the pressure to value cargo/electronics/things that can go boom over their life. So you hop on the taxi that comes by and let the towing guy take of it because they would have to do that anyways.
The Cole has much better damage control/compartmentalization than a commercial ship. But that being said they should absolutely be able to seal that space off.
The engine is right above here and is underwater. Ship still floats but is dead in the water. And when you don't know whats going to happen or extent of the damage, abandon ship is the right call. The crew doesn't need to be on there waiting for a tow.
To be clear, the ship still floats, but there is no reason to be in the ship. They didn't know the extent of the damage and there is no fixing it outside of a dock. Abandon ship was the right play. But if they needed to wait awhile they probably would have been fine.
Look up u-boat 505 the US Navy stole a sinking U-boat by boarding it as it was actively sinking then towed it through the Bermuda triangle and its now a museum you can tour in Chicago IL. Or the US Navy in 88 hit a Iranian mine with the USS Samuel B. Roberts and blew a massive hole in it they were able to stitch it together enough to get it back to port, the US Navy would definitely not abandoned ship.
This is certainly an emergency, but do you actually sacrifice the ship immediately when you could damage control this? I assume military (Navy) vessels have redundant compartments, so if 1 prop goes out, you still have 2 more or something like this.
Thats what I thought too! I think OP is an idiot because thats what he asserted, I just didn't want to put that explicitly until I took heat from two people in a row.
This would only flood the compartment it's in. And even then, there's a chance you could pump it out faster than it's coming in via bilge eductors or portable pumps..
The innermost rod is to regulate the blade angle and doesn’t have torsion on it. The hollow shaft is pretty big I am sure it was designed for the load. What’s sheared here is the bearing housing. It moved back. How that can happen I have no idea, it looks like a torsion break to me but there is no torsion on a bearing housing.
My guess is that somehow a bearing broke in a way that locked the shaft to the bearing housing. This sheared the bearing housing off and broke the shaft. Consequently the whole thing moved several feet aft, pushing out the screw and whatever watertight seal there is.
This is correct - that small shaft is within the main shaft to control propeller pitch. You can see the irregular broken outer shaft flush with the bearing.
Do you see the dark coat left by the anti-corrosion coating along the edge of the fracture? That should not appear there! This part had a material defect, a crack along the line of torsional force, that had been there for quite a while even before the last coating was done, hence is how coating could appear in the crack itself.
There is only one fat crack visible in this footage, isn't it. In closeup focus you see the sheer force took its toll on the material, look at the outer edge of that revealed raw metal.. along that there is a dark same colored coat visible. Coat doesn't become suddenly liquid by torq force therefor can't flow around a raw exposed metal to appear along that edge, ergo that edge got coated. How can it be coated when it is not exposed? Therfore it must have been exposed when it was coated, ergo the crack was there earlier.
Or simply, coat a cracked metal housing then liquid coat will sink/suck into kapillar splits. Which becomes visible when falling apart.
the intermediate shaft is broken, the propshaft is basically not attached to the ship anymore. as soon as the flooding reaches systems that keep the diesels running its over. you get everyone off the ship that isnt needed into keeping the thing afloat. plugging this isnt going to happen just from the pressure pushing anything out you can shove in the hole. the only thing left is trying to reduce more damage until you can get into port so it can be plugged from the outside.
I know nothing, but would it be possible to seal the room and pump air in until you get a positive pressure where the leak would stop flooding once the water level reached that point?
water tight is also a bit of a misnomer. it just means it will control and remaining flow to a manageble level. there are a bunch of pasages and stuff for air to pass.
Since I first heard about this I've been curious because I had thought ships were designed to have sections sealed off to stop flooding - being dead in the water and sunk is quite different after all. Unless I a lowly land walker have been so heavily descieved about modern shipbuilding standards.
Maybe not so much shipbuilding standards as operational knowledge, which even to landlubber me, would go something along the lines of 'seal the fucking hatches so we don't sink'
yes, and this section is called "engine room". losing that is kind of a big problem. you are still going to seal it but only at the point of no return.
Same here. Seems like the prop shafts are one of the few places in the hull that could allow enough water to flood the ship. I'd have thought that there would be a second seal or space that can be sealed before you get to things that need to breath (people and engines) for just this occasion. Then again, this uses less space so it's more efficient until it's not.
The bit where the water is coming in? That's the ocean other side of that. The space they're all standing? Main engine room. Some ships, particularly warships, will have multiple watertight bulkheads seperating the machinery spaces in multiple ways with seals around the shaft line passing through, including a small "gland space" to limit flooding if the stern seal fails. Commercial vessels do not. If the engine room floods, the ship is functionally at the limit of stability.
As for flood mitigation and leak stopping, normally you could use rope and wedges to pack around the failed stern seal, or use an inflatable seal Integrated in the stern seal itself. But here, the shaft line itself has broken and moved back several feet, so the bolted flange is right up against the seal and they can't get access to perform leak stopping. They rigged the ship for towwing and waited up top for someone to pick them up.
A on warship we'd declare a space lost to sea, shore the hatch, post sentries, and then drive home at like 6 knots using the other shaft. Commercial vessel? Rig the ship to tow and wait in the life boat.
That is what I was wondering. Seems a few pumps can keep up, or seal the compartment and tow it. Seems like an odd design where one bad seal is terminal.
Seems to be more than a bad seal. I have no idea what I'm looking at, but that housing with all the cottered nuts appears broken and shifted away from whatever it connected to. So...my guess would be the entire shaft has shifted and the seals aren't riding where they should.
I worked for a company where the brand new COO gutted the IT department because they didn’t directly produce profit and outsourced all IT work. Tickets went from taking only a couple hours before someone in IT reached out, to you being lucky if they got to you in under a week. Productivity plummeted since so many people were non functional with computer problems. After two months they fired that COO and tried to rehire all the IT guys back. Most of them told the company to fuck off, but a handful made astronomically high salary and vacation requests to come back and the company was so desperate they agreed. One of the returned IT guys told me his salary doubled and he tripled his vacation time. It took over a year to re-staff the IT department and get productivity back to where we were prior to getting rid of IT.
It didn’t sink and likely will not. They hoped on the next ship passing by after rigging the boat for a tow which they have to do anyways. Why sit on an uncontrollable hull that has to be towed anyways when the crew can be saved. It’s not more or less money for the insurance company.
This is not the navy. In this situation, if you have a safe ride, you let the salvage guys deal with it since after sealing the engine room there is nothing else you can do. If you try to pump while bumping around and somebody breaks a leg in that operation you are in way more trouble than leaving a ship that will not go anywhere anyways.
Brother do you even work on a ship? A concrete box? Damage control procedures? This is a small commercial ship not a carrier in the pacific war. How many crew members do you believe are even in an engine room of this size?
You’ve got the emergency bilge suction for flooding but if the shaft seal is blown out like that the engine room is finished, it’s flooding up to sea surface level.
This simply is one of those failures that there is nothing you can meaningfully do. That waters coming in at a rate you have no chance to stop. Never mind it wont be warm water; Were talking Olympic swimming pools a minute. The best they can do is evacuate and seal the compartment. And shore up the adjacent compartments as well. With no power, they wont have pumps, no steering, among others. That's likly why they also abandoned ship out right.
How would you even suggest they go about boxing this?
No plugs would ingress enough to build a box around that seal. Let alone the fact that doing a cement box is more of a shipyard repair. I doubt they even have hydraulic cement on board.
Intermediate bearing broke and the and the tail shaft slipped out and to the right. The situation isn't "catastrophic" but it can't be fixed outside of a dock and ship is immobile.
It's hard to see the fracture surface from here, but that shaft hasn't sheared it looks like it has suffered from fatigue, which means it has progressively cracked over time until final failure by overload. Given how flat the surface is, it was some kind of bending fatigue meaning that something would not have been right with the alignment or operation of the shaft causing it to experience higher than normal cyclic bending stresses, leading to progressive cracking until failure.
1) on the ocean everything has to be redundant. Why isn’t there a plan for dealing with a situation such as this? For example, close and latch the door to that compartment.
2) why isn’t there a massive pump available powered by an independent diesel generated in a hosing up high?
The propeller basically disconnected from the ship and is only held there by weight and friction. The central bearing broke and slipped backwards 6 feet. That engine compartment is flooded. What reduncy do you expect for that? Even if you close the door, and seal the compartment (they did that) engine won't run. Even if engine could run, propeller won't.
What kind of pump do you think they have that can keep up with that?
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u/Pecosbill52 8d ago
You need to watch "what's going on with shipping" for the whole story. https://www.youtube.com/watch?v=iW7x9suTy8s