North Korea says it has successfully refloated a new destroyer that capsized upon launch last month, with state media reporting the damaged vessel will be moved to a dry dock in a different shipyard for repairs.
“After restoring the balance of the destroyer early in June, the team moored it at the pier by safely conducting its end launching on Thursday afternoon,” a report from the state-run Korean Central News Agency (KCNA) said.
A satellite photo taken by Planet Labs on June 5 showed the formerly stricken vessel righted and seemingly floating in water away from the pier where the disastrous launch took place.
The ship floating is not the surprising part. It’s the fact seawater was into everything.
Dip your computer into the sea for a few weeks, it isn’t going to be happy about it.
Yeah a good analogy is refloating the Costa Concordia. They patched the hole and emptied the water and it certainly floated, fixing the hole in the hull wasn’t the problem. Refloating it didn’t return it to passenger service, it was just step one of being scrapped, because that’s all you can do with a ship like that short of completely rebuilding it from scratch. Repairing it would be vastly more complex, risky, and expensive than simply replacing it. It’s salvage and scrap, that’s all. You get it out of the way so its not blocking your route as a hazard to navigation, anything you can salvage you salvage, then you scrap it.
Now, on the other hand, if you wanted to do some theatrical performance of how you are the greatest and most resourceful country on Earth, you could certainly refloat it and jury rig it piecemeal until it looks like a perfectly functional ship again, as long as nobody has to go inside and it never has to perform any significant functions. If you want to use it as a floating barge to launch missiles from (like the first of its class, which is rumoured to have no engines as it has never been seen moving under its own power) then absolutely you can refloat it and use it for that no problem. That might be a good way to save face if you’re a recently-embarrassed despotic banana republic with nuclear weapons and no functioning economy, and plausibly that is what will happen here.
Some of the ship never made it into the water during the launch, and the water it did go into was presumably shallow. It might be that a relatively small portion of the ship was actually immersed.
The problem honestly isn’t even the seawater, necessarily. Even that is technically fixable.
Where it gets potentially unfixable is that most naval architects seem to think that the ship probably twisted her keel lying in that position. Non-naval-architects might not appreciate what a catastrophic problem that is, to put it roughly in automotive terms that’s like having a twisted frame on a car (it’s actually significantly worse, but that’s the closest layperson analogy you’re likely to get). There’s nothing you can do to to a twisted frame to exactly straighten it, and it will never drive “properly” again, in fact it can be extremely unstable and unsafe. Cars that this happens to are basically without exception considered “totaled” and for good reason.
Ships, in general, and warships, in particular, can be put under pretty extreme forces by the water they are in, especially at high speeds or heavy seas, and even small imperfections in the shape of the hull can cause very serious hydrodynamic drag and forces. These effects can be even stronger and more dramatic than aerodynamic effects on cars or airplanes since the water itself is so much thicker and heavier as a fluid. A ship with a twisted hull is almost certainly a write-off, and if you stubbornly refuse to accept that and do everything you can to mitigate it, even if you are lucky it will still likely be a poor, dangerous sailer that can never safely approach anything near the sort of speeds it was originally designed to achieve. A warship that can only go half the speed, and half the range it was designed to, with a non-negligible chance that it may be so poorly handling that it is at least uncomfortable and hard to crew, if not actually dangerous or even doomed in heavy weather, is not a very useful warship, no matter how hard you are committed to putting it into service despite the damage.
Yeah, maybe it still floats, but that’s only a small part of what a ship is actually expected to be able to do in the real world, and “modern warship” is a pretty unforgiving role that needs every bit of performance the ship is supposed to be able to provide. It’s not a situation where you can accept having a scratch-and-dent salvage title if you want it to actually be good at its job. That’s why people are considering this a total loss (and it still will be no matter how much work they put into it).
Thanks for an amazing explanation of the problems. 👍
TIL
Massive ships don’t get launched into shallow waters
As I recall from an earlier article, the reason that they did the (normally less desirable) sideways launch is because this facility normally works on smaller boats.
kagis
Additionally, the new imagery reveals that dredging work has begun to deepen and widen the fairway at the harbor’s exit. Defense Express suggests that this could be in preparation to bring in heavy equipment, possibly a large barge with a crane.
However, the DPRK lacks sufficient barge-mounted cranes capable of lifting and repositioning the destroyer’s bow. Instead, inflatable balloons have been deployed. The most likely concern is that even if the destroyer is successfully rebalanced, it may not be able to exit the harbor and could run aground.
The draft of the Choe Hyon-class is unknown, but given its dimensions and displacement, it is likely around 5 meters.
Old satellite imagery shows that the fairway was artificially deepened in 2021. However, the general depth remains shallow, having been designed for fishing boats and barges — not warships of this size. It is therefore likely that the existing depth is either insufficient or marginal for the destroyer’s passage. To avoid another failure and further embarrassment, North Korea has apparently decided to deepen the fairway further.
l’d bet that they probably have about the minimum required to get the thing out to deeper water.
Exactly. Look at a current US Navy ship like the USS Beloit and it has a reported draft of 14 feet. You’re going to want to launch a ship like that into deeper water than what it drafts so that it doesn’t bottom out and damage the hull.
When they said it was going to be refloated and serviceable in a month. It’s basically scrap at this point. WWII ships you could salvage, modern stuff is kilometres of cabling connected to computers. Fix the hull and replace everything inside. Unless this isn’t as advanced as it’s made out to be.
It’s North Korea. It’s absolutely not nearly as advanced as they claim it to be.
Weren’t there jokes at the time about them inadvertently building a submarine?
Or they could have left it underwater and in a few hundred years have a ship museum about it.
The next generation of NK navy ships will have glass bottoms to investigate what happened to the last generation…
Kim Jong-un looking like he’s about to ask you to come visit his island for the weekend and perhaps pen a wee testimonial. Wonder if he also has a jet standing by at Choteau?
