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North Korean Ship Fails/Capsizes at Launch in Front of Kim

racookpe1978

Nuclear
Feb 1, 2007
5,988
Details from the available British Commercial Press are few, and what is published contradicts itself.
"
In a statement KCNA said: 'Due to immature command and operational negligence, the parallel movement of the bogies could not be guaranteed, resulting in the launching sled in the stern detaching first and causing the ship to capsize.

'The ship's balance was destroyed due to a rupture in the hull in some sections, and the bow section was unable to detach from the keel.'"


Basically, a North Korean frigate (about 5000 tons displacement) either capsized or rolled off of its forward launch platform when a "dolly" collapsed during the movement.
My assumption is that it was a sideways launch using two cradles, and the stern cradle released first. The bow was still fixed, and the hull torn apart as the ship twisted. The ship did not "capsize" in the water, but rolled over on the launch rails.

Several workers were killed, others injured. But, this is in North Korea. And, in North Korea in front of a public ceremony in front of their Leader. Many more will be killed in retribution for the insult to the Leader. And their families, their relatives of the workers, designers, engineers, and shipyard crew.

Strategically, obviously their Navy is hurt by the loss of a future ship, and the damage to the shipyard and its docks and launch gear. And, any losses to the North Korean arms build up helps the world. But, instead of a "lessons learned" improvement, they will lose dozens (hundreds ?) of irreplaceable launch crew and workers in punishments that will delay future construction for years.
 
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That side slideway type of launching is one of the safest methods from a stability standpoint but it does rely on a crew to cut multiple restraining bars simultaneously during the launch. Transitioning from being supported from the bottom to supported by buoyancy can create some challenges. It's best to just huck it into the water sideways.
 
Stern launch ("Break the champagne bottle on the stem") creates the greatest stress on the hull girder as the stern begins to get bouyant, but the bow is only partially cradled by the forward half of the sliding ways. Launching is a tricky problem, aside from the "simple" weight and moment and center of gravity issues. (Which are not simple at all!)

That's why this incident, and the shipyard and navy people who will be murdered because of it, will be so destructive to the NK Navy construction. /and that is a good thing
 
Stern launch is also the most challenging in terms of stability because the narrow now is supported on centerline blocks and the only a fraction of the vessel is buoyant to provide righting moment.

 

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