North Korea 'sunk South Korean warship', killing 46 sailors

[Scriblerus the Philosophe]

http://www.news.com.au/world/north-korea-sunk-south-korean-warship-killing-46-sailors/story-e6frfkyi-1225856989612

AN elite North Korean suicide squad of human torpedoes may have been involved in the sinking of a South Korean ship in mysterious circumstances.

South Korea's Defence Intelligence Command had alerted the Navy weeks ahead of the sinking that North Korean suicide squads were being deployed, according to reports in Seoul, Sky News reports

The "Human torpedo" squads were said to involve small submarines, Sky News reports.

They are navigated so close to the target that their torpedoes or explosives blow up both target and the attackers.

They can also be timed to explode while the attackers escape from the vessel, the mass-circulation South Korean newspaper Chosun Ilbo reported.

The attack by North Korea on the 1200-tonne Cheonan claimed the lives of more than 40 sailors and  was in retaliation for an earlier naval defeat, the report added.

"It is the military intelligence's assessment that the North attacked with a heavy torpedo," a military source was quoted as saying by the news agency Yonhap.

"The military intelligence has made the report to the Blue House - the Presidential residence - and to the Defence Ministry immediately after the sinking of the Cheonan that it is clearly the work of North Korea's military," the source added.

South Korea now plans to raise the front half of the Cheonan, which went down near a disputed sea border with North Korea.

It will issue its verdict on the cause of the explosion that sank the warship after that.

If Pyongyang did carry out the attack it would be the deadliest confrontation between the two countries since the Korean War ended in 1953.

The North has denied it had anything to do with the sinking.

[Sibling Zono (anon1mat0)]

Two things.

1. I wouldn't think impossible for the N.Koreans to use some form a kamikazes. Also they are indeed the first suspect after the sinking of the boat.

But...

2. The idea of using a kamikaze on this day and age would suggest an extremely underdeveloped military program on part of the N.Koreans and that is incredibly hard to believe considering that they have been starving their own people to fund the military.

My main hypothesis would be that the hard liners in S.Korea want to paint the north in the same light as the Japanese 70 years before (ie: The Bogeyman) after what could possibly may have been a mine or even possibly a torpedo.

It wouldn't be the first time the N.Koreans probe the tolerance of the west and frankly until China decides that it doesn't want to deal with them anymore they will keep trying to use said stunts as leverage. Not an easy problem to solve.

[Aggie]

I had heard it was a Korean-war era mine, which seemed a little suspicious.  SK didn't seem to want to make a big deal of it at the time.

@ 2. Considering they have little international trade, Soviet aid is pretty much dried up and force military service is universal for men and extremely long in duration, that massive military spending may consist largely of rations, guns and fuel (plus whatever money gets thrown down the nuclear warhead and missile development program hole).

[Swatopluk]

North Korea loves mini-subs. They seem to be one of the main means for infiltrating the South. I also believe that manned torpedos (with or without a warhead) are still part of the standard naval arsenal of many nations (for use by special forces, SEALs, Kampfschwimmer etc.).
I would not fully exclude scenario #2 but consider #1 to be quite consistent with the North's typical behaviour. The North also has the means to 'motivate' even kamikaze actions ("die quickly and a hero or suffer the (slow and painful) fate of a traitor together with your loved ones"). Not all Japanese kamikaze pilots were volunteers either (not to forget German and Russian equivalents).

[ivor]

How did they not hear a torpedo coming?

[Swatopluk]

In case of manned torpedos the typical high-pitched sounds may be missing. If it was torpedos fired from a mini-sub at close (selfdestructive) range there might not have been time to react (minis can run pretty silent and may approch undetected). Also no idea whether the ship in question would have hydrophones manned round the clock. Pure speculation on my part.

[ivor]

They should have been listening since there were "torpedo" threats made before this happened.  I can't see any torpedo hitting a ship that's "manned" or "unmanned" without making noise.  If the ship was underway the torpedo would have to be making noise to catch the ship.  I think they hit a mine are just turning the whole thing into propaganda.

[Swatopluk]

At slow speeds non-nuclear subs can be close to undetectable by passive means. And it is implied that, if it was a manned attack, it was close range enough to destroy the attacker too. In that case a fired torpedo would be below the victim before practical countermeasures could be taken.
There was no statement about how fast (if at all) the South Korean boat was going, so I can't say whether a sneak attack was possible.

[Sibling Zono (anon1mat0)]

If you were able to sneak in without been detected wouldn't it make more sense to plant a bomb in a critical part of the hull? That would have the advantage of enough time to get away to a safe distance.

[ivor]

Hmmm....  Those ships were ASW equipped, they were listening.  Couldn't have been a submarine.  Had to have been a mine.  You might not have heard the sub, but you would have certainly heard the torpedo.  As far as I know you can't slow a torpedo, unless it has a ninja mode for slow targets.

Certainly the crew knows what happened. If the boat got lifted out of the water with no warning it was a mine.

"There was the sound of an explosion and the ship keeled to the right. We lost power and telecommunications," Yonhap quoted Choi Won-il as saying.

Must have been a mine.  The ship split in half.

[Swatopluk]

I have to dissent on the torpedo speed question at least in general. Some (esp. older) models can be tuned down to walking speed (and a consequently vastly increased range/endurance).
Just to be clear I have no preferred opinion in this case. I just come up with possible scenarios.
If the ship was moving in any significant way (let's say above 3 knots), only mine or torpedo are possible. And with the ship split in half it could not even be a moored mine. Rule of thumbs: direct hits tear holes, explosions at a distance* break.
This would also likely exclude a bomb attached to the ship.

*below the keel

[ivor]

Yup, you're right.  Those sneaky bastards!  I never heard of that.  Changing a torpedo's speed I mean.  I was a surface guy so I know about ASW, not so much about subs and torpedoes.  If I was in water where there was a threat of such things I'd be moving fast all the time.

Sounds like the ship sank in shallow water.  A great place to put influence mines.  I'll bet it was the same kind of mine that damaged the Princeton and the Tripoli in Gulf I.

[Swatopluk]

The German navy in 1944 modified one of their standard electric torpedoes to become essentially a moving minefield. It would run at slow speed for several hours following a programmed 'search' pattern. It was used in the aftermath of the Normandy landings. Literature gives a range of 57 km at 9 kn (about 3.5 hours). It would run 27 km straight, then switch to search pattern. Of the first batch of 90 (fired at night) 30 seem to have hit something since explosions were detected.
The minimum speed is limited only by the need to keep the depth (torpedos have neghative buoyancy) and the rudder still working.
---
Let's see with what result the South Koreans will come up.

[Sibling Zono (anon1mat0)]

How about a scuba diver with a rebreather? Wouldn't that be silent enough?

[Swatopluk]

Works only against static targets (and the diver has to get there first). And see remarks above about the effects of attached charges as opposed to 'backbreaker' explosions at a distance.