Saturday, April 17, 2010

That ain't an internal explosion ....


Bit by bit, the truth will come out. I'm still voting mine.
A South Korean investigator said Friday that an "external explosion" was the most likely cause of the mysterious sinking of a naval ship in which 46 South Korean sailors were lost in tense waters off the North Korean coast.

"There is a higher possibility of an external rather than an internal explosion," Yoon Duk-yong, the co-head of a government-appointed team to investigate the March 26 sinking of the corvette Cheonan, said Friday in a televised press conference.
The Cheonan's stern section, where the missing sailors were believed to have been trapped, was raised from the Yellow Sea bottom Thursday after a salvage operation that was made both risky and difficult by low underwater visibility and strong currents. The bow section is expected to be salvaged next week.

Of the Cheonan's 104-man crew, 58 men were rescued from the sea on the night of the explosion. Thirty-eight bodies have so far been recovered; eight remain missing.

54 comments:

surfcaster said...

Tick... tock... tick... tock...

Would this mine ignore other type vessels? That area must have significant fishing / commerce vessels running around in addition to the military traffic. Fishing vessels dragging nets would find many mines? Or something drifted out of NORK waters? Nork fishing boats avoiding specific areas in NORK waters. Rambling, I know. Just few possibilities, right? Mostly remote? What is the most simple answer?

/ramble

CV60 said...

My vote is torpedo, followed by a very recently laid bottom influence mine.  As many fishing vessels as there are out there would have likely detonated an influence mine that had been there awhile.  A moored contact mine that had broken free would not have broken the ship in half (although it very well may have sunk it).  This looks like an influence trigger.

ewok40k said...

AFAIK there was no reported contact with NK surface vessels, so if this was torpedo then sub was probably involved. Mine would suggest some modern type able to distinguish military targets from civilian traffic.

david said...

What would happen if this was a US ship? Would it take a similarly long time to determine what happened? From an outside perspective, it seems like North Korea has gotten away with sinking a S. Korean warship and will suffer no retaliation. The lesson is that if you just sink one ship and don't claim credit ... then you win.

I'm no naval genius strategist, but isn't it an important principle to establish that countries can't be allowed to get away with this kind of thing?

Byron said...

Even a 533mm torp would have blown the stern off; ditto mine. LWT, anyone? And is there a better picture?

pk said...

might have been a torpedo launched from a shore battery.

C

C-dore 14 said...

I'd say we'd react a bit faster but not much.  It's one thing to determine what destroyed a ship and another to fix responsibility and take action.  I'm assuming that the ROKs want to be certain before moving ahead (much like we would).

AW1 Tim said...

  I also vote for torpedo. Although there is a good argument to be made for a mine, it's just too much to ask to believe that with all the surface traffic in that area that a ROK Naval vessel is the only one to get hit.

   It was a deliberate attack, IMHO.

C-dore 14 said...

A mine would be my guess too.  The question is whether it's of a 1950s vintage or somewhat more recent.  As for the civilian traffic in the area, mines laid during both world wars used to pop up in the Adriatic occasionally while we were working there during the Bosnian civil war.   

xformed said...

Possibly a 2 man driven torpedo?  I seem to recall when this went down a few reports in the blogosphere regarding the NOKs having special ops teams that did that, much like the Japanese plans at the end of WWII.  And...not like it hasn't been done before elsewhere.

Byron said...

I didn't think of the third possibility: a limpet mine. The NORKS pride themselves on their special forces, it'd be just like them to pull a stunt like this. And I really don't see a hell of a lot of damage. Remember the hole in the Sammy B? Princeton?

Jay said...

I find it interesting the the NORKs did not claim credit.  Not sure if the sinking of a single corvette could be filed under "sending a message", but then again, they have pulled some crazy nonsense before...

surfcaster said...

Norks apparently for the first time are saying they are not responsible: "As South Korea can't identify the cause of the accident, they are using the media to attribute it to us," said a statement carried by state media.

http://news.bbc.co.uk/2/hi/asia-pacific/8626710.stm

Outlaw Mike said...

Uh, Byron, not a lot of damage? I am just a schtoopid beljun taxpayer, but what I see in that photo is half of a ship.

AW1 Tim said...

 Wouldn't surprise me at all. Kin Jong isn't gonna be around a whole lot longer, and some of the snior leadership might well be seeing just where the trip wires are these days.

  Course, it may well turn out to be an old mine, but the way that ship was broken in half looks like something went kaboom UNDER the keel.

   Respects,

DJ Elliott said...

With the right acoustic/magnetic trigger, a mine will ignore everything except the signature it is programed for.  Most military ships have a distinctly different signature from merchant/fishing traffic...

Byron said...

Mea Culpa...after looking at the "before" picture, it looks like she broke in half. The picture Phib has up looks like the after half of the ship. Suspect that means she ran up on an old moored  contact mine.

Anyone remember the old wood minesweeps? Remember they had a canvas roof over the bridge? I read a DC book on the bridge one day while waiting for someone to bring some parts over to the ship so I could get back to work, and saw something that stunned me: It seems the reason for a canvas roof was simple. If the 'sweep ran into a contact mine, the bridge watch would be punched through the canvas and over the side, hopefully surviving the broken legs and backs they would surely have. Of course, the canvas had so many coats of paint that it was like metal...

CV60 said...

While a influence mine can be set to a specific type of ship, that argues for a recently laid mine, ie, not one of Korean war vintage or even in the past few years.   From what I understand, that area is both heavily patrolled and heavily fished.  Therefore, an older influence mine would have likely already been activated or discovered.  A contact mine, being less effective, would likely not have broken the ship in half.  THerefore, that argues for either a recently laid influence mine or torpedo.  Because the area is heavily patrolled, laying an influence mine, unless done by submarine, would have been difficult.  Therefore, I'm voting for torpedo.

Anonymous said...

That is a true statement. I served on MSO-438. Remember the words likes yesterday, "The ship has entered a mine danger area. All non-essential personnel lay topside. Stand clear of all overhangs and overhead obstructions." You would probably break your neck on the wooden frame supporting the rag top, though.

DirtyBlueshirt said...

It's also an important principle that nuclear powers don't go to war with one another.  Our problems on the Korean peninsula aren't going to be solved in Pyongyang, they're going to be solved in Beijing.  Kim will stay in power exactly as long as he's useful to China and not 15 minutes longer and everyone knows it.

ewok40k said...

either way, a sub is suspect no1 as both recently laid mine and torpedo needed sub as delivery...
what is SK ASW capability compared to NK sub capability?
in a larger picture, how do compare these capabilities in US vs PRC?

MR T's Haircut said...

I dont see why we are dithering on this...  South Korean Ship SUNK.  North Koreans did it. 

take action to prevent a recurrence...

MR T's Haircut said...

Is there a Current NOTAM issued for this water area?  If it was a left over mine the NOTAMS should be published...

Old NFO said...

Of course we're dithering.  That's what we do.  We dithered until the North Koreans had nukes.  Just like we're doing with the Iranians.  We'll likely do something if the North Korean's nuke the South, maybe not.  I'm sure we'll sponsor a strongly worded UN resolution when the Iranians nuke Tel Aviv.  Actual action?  Almost certainly not, after all we wouldn't want to upset the "Arab Street."  No such concern with the NORK's.

Grandpa Bluewater said...

MINE.  Left over mine very possible, there have been a lot of mines in those waters over the last 75 years. Rust never sleeps, eventually the anchor shackle pin rubs throught the mooring padeye on the bottom of the charge, the 1905 issue Czarist navy mine deployed 45 years later pops to the surface after 55 more years and drifts. 5 years later,  patrol boat running along goes bump, the mine horn does what is was designed to do 110 years ago (Russians kind of genetically design for rugged, if crude, ordnance, just as long as it works for an looong time).

Boooooom!

Unlikely?  We're talking about Korea!

Grandpa Bluewater said...

T:

There was, may still be, a standing NOTMAR on drifting mines since 1945, maybe since Notices to Mariners have been issued.

sid said...

Now see!!!

Whats needed in this situation is the LCS!!!!!

It can scream through these mine danger areas at very high speed...and kinda like going over a speed bump at 90mph...just bounce right over these puppies!!!!!!

And beside.

The LCS HAS to be the best ship for the job because -you know- IT JUST LOOKS SO COOL!!!!!!

And its about time all you Old Farts Start Getting It.

Michael said...

I think the "smart money" has been on a leftover mine from the last round in the 50's. Probably a contact type rather than an influence mine. I recall the Russians lost the Novorossiysk in 1955 to an influence mine but I would not accept that a cell in the mine could last almost 50 years. A contact mine by its very nature, generates its firing impulse on contact and therefore remains dangerous for much longer. Here in the North Sea and English Channel we clear contact mines left over from WW1 and WW" and don't take chances - blow them up in situ rather than take stupid risks.
As to the idea that it was a more recently placed mine. A possibility that an existing minefield was relaid and there was a "stray" and a tragic accident. As a deliberate act of provocation? No direct political benefit to North Korea or Kim so I am inclined to put it into the awful bad luck category.

UltimaRatioRegis said...

IIRC, didn't the initial reports have something striking much farther astern?  There was significant discussion of a wake homing torp.


Sid is right in his below comments.  This is a job for LCS.  It looks way too cool to hit a contact mine left over from the beginning of the last century.

Grandpa Bluewater said...

URR:

There are reports and then there is twisted metal.  Me, I go with the twisted metal.

The mines that sealed off Wonsan, which was taken from the land side, because we took so long for mine clearance after CO, USS Pirate was last seen in a photo high atop the cloud from the explosion that destroyed the minesweeper he commanded, were Russian 1905 mines from the Siberian mine depot in Vlad, if memory serves.

My condolences to his family, I mean no disrespect. I rather report it in hopes of inspiring the youth to remember him and make your sacrifice have some small positive repercussions. RIP.
God bless you and keep you and may you meet in a better place. Most sincerely and respectfully.

MR T's Haircut said...

Not me.  My Carbureators rusted out after one season of Ethanol on my Mercury Motor... No sir.. Russians are known for crap.. no way this was a mine...

ewok40k said...

having entire division of US troops in South Korea as hostages does wonders...
the zero casualties policy is making US powerless

Anthony Mirvish said...

If it were part of a deliberately laid new minefield, wouldn't the salvage ships have found some evidence of others?  The drifting mine theory seems more plausible just because there have been lots of mines laid in those waters over the last century.

I'm impressed with the speed and capability the South Koreans have shown in the salvage operation.

Hamilton said...

It was and still is Blue Crab season in that area, from 300 to 400 fishing ships comb that area everyday and they are out all day and into part of the night.  The last mine recovered was in the late 1980s and it wasn't functional.  A contact mine is highly unlikely, and even more so from where it would have hit the ship.  The crew heard a bang and were thrown upward. 

Hamilton said...

Anthony,
That area has several hundred Chinese and South Korean fishing vessles pulling in their Blue Crab haul.  The season opened just prior to the "incident" and is still active.  Statistically a contact mine would have blown a fishing ship out of the water.  Could it be a 1 in a Million shot that a one hundred and five year old mine (1905 model) that has been in the water for 57 to 60 years just broke free and hit one of the few military boats in the area?  Sure, but I don't like those odds.  SK has a heck of a time keeping the fishing fleets in line, wouldn't be that hard for a North Korean Sub to sneak in.

The speed and capability of the salvage operation has had a large human cost.  SK lost an expert diver early on, and has crashed two helicopters losing an additonal 4 crew.

LCDR said...

Definitely an external explosion, based on the photos.  Given the location, the ordnance involved is almost certainly North Korean.  The only remaining questions regarding the facts of the event are: 1. Torpedo or mine?  2. if it was a mine, was it recently deployed, or left over from a previous era?

Since the Korean War never really ended -- and tends to flare up again from time to time -- this is largely an academic discussion.  The real question is: What is South Korea going to do about it? 

My best guess: Not much.

ewok40k said...

lets sum this up:
drifting old mine - plus: they really show up all the time, minus: what are the chance of it hitting exactly that ship among the all crab boats?
newly laid mine - plus: explosion pattern fits and modern mines have ability to chose targets precisely, minus: how it was laid and why there are no others found?
torpedo - plus: explosion pattern mostly fits, minus: how it was launched?

ergo:
excluding surface combatant (no contacts were reported) most likely culprit is sub, either laying mines or attacking with torps

MR T's Haircut said...

Ewok,

American Soldiers in Korea are not "Hostages". 

LT B said...

GB,
   When I last visited the the WNR Museum, they have an exhibit on MIW.  They mentioned Wonsan and attributed poor mine clearing to a lack of funding and interest after WW2.  They also said that Bob Hope made it across land before the Marines coming inland due to the snail's pace of clearing routes into the harbor.

ewok40k said...

with NK having nukes and no 100% safe missile shield in place they are hostages...

Anthony Mirvish said...

Hamilton,

All true, but coincidences do happen.  What were the odds HMS Hood would get sunk by a single shot? 

I am aware that SK has paid a real cost to mount this salvage operation.

TBR said...

My bet is on a passive accoustic homing torpedo, based on the hit location (breaking point is the engine room) and damage picture. This does not necessarily mean sub-launched, might as well be a submarine laid mine modification of a Chinese made Yu-2 or Yu-4A ASuW torpedo though I'd class the 21inch Yu-4A the more likely of the two.

Old NFO said...

If want to know what we'd do now, just look what we've done in the past and extrapolate considering who's in charge now.  USS Stark, USS Cole and the EP-3 intercepted in international airspace and forced to land in China.  Strongly worded statement maybe?  Serious consideration of sanctions?

Grandpa Bluewater said...

Hamilton and TBR:

Passive homing torpedoes generally home on the highest amplitude broadband noise in the bandpass of the torpedo's hydrophones. That would not be engine tones, but rather cavitation at the blade tip of the screw propellor(s). The torpedo track after acquision would follow the characteristic pursuit curve imposed by homing on the instantaneous bearing of the target as its relative bearing changed to the right or left of torpedo instantaneous course, so terminal homing just prior to contact or magnetic influence warhead detonation would be from "dead" astern or nearly so of the target. Stern and the screws are undamaged. QED.  
    Our  drifting mine  could have been adrift for a bit.  Absent accurate pilot charts mapping the offshore currents of the west side  of Korea,(err, based on Japanese surveys in the 30's, you know, like our charts of Saipan and Tinian until less than 5 years ago),  who can predict where it drifted from? Maybe the anchor cable never deployed and it's just been sitting there for 55 years on the bottom, inert, until the wooden wedge jammed in for over road shipment and not removed rotted away , the charge cable unreeled & it armed an hr before. Quien sabe!
    Crabbers work crabbing grounds, bottom crawlers would avoid locations with much current at all, would they not?  A patrol craft buzzing through would go around the crabbers, albeit at relatively close ranges (50- 500 yards), which would be over the low bottom current locations (crabtowns), so they might  follow a habitual track stemming the local current stream of a flood or ebb, and avoid the fairway for big ship traffic. Crab pots wind up where the crabs are and cheap GPS means same spot . Crabbers will not waste fuel, use the known shortest route and avoid bucking a flood tide.  Point: less random than it might appear.
    Sure, it's a low individual probability, but that just means it won't happen very often.  Given enough mines over enough time (plenty of both in this case) it means, "nya, its a possibility, Doc." They still blow up a couple of french farmers a decade plowing around Verdun and the Somme. Explosives do tend to get touchier with age.a hard rap might do it.
   Or it could have been a limpet mine attached by a swimmer.  I doubt we'll ever know for sure. Leave my chips on the square on the felt marked "MINE".

SCOTTtheBADGER said...

Man, that really is a proper crane, isn't it?  I suspect a mine, myself. If a torpedo, wouldn't the frigate's sonar watch have heard the high spped ttransients approaching, and at least have known what was coming, even if it was too late to do anything about it? 

Andrewdb said...

John Batchelor's show was reporting that there was some altercation back in November in that general area when an NK ship came south of the line, and eventually the SK Navy shot it up fairly badly - so there certainly is motive for a new "mine" (as if the NKs need "motive").  More info here: http://www.historyguy.com/korean_naval_battle_2009.htm

This might make it less likely this is something left over from WWII or Korea War.(?)

MR T's Haircut said...

Ewok, you have no idea what you are talking about,

Wharf Rat said...

I would think that the USS George Washington CVN 73 CVB would argue with a description of any US Military Personnel as 'hostages'.  I'm guesssing USS Essex LHD 2 would also challenge the description.

And that's just the Navy.

ewok40k said...

then tell me what US politician will have the guts to tell the nation: we have just lost 10.000 men in Korea?

Anonymous said...

More here: http://english.chosun.com/site/data/html_dir/2010/04/19/2010041901395.html 

I don't know how reliable that source is.

Anonymous said...

Gerrrr.  That was me

Andrewdb

TBR said...

That presupposes that the corvette was actually doing enough revolutions at the time of the explosion. Somehow I have the picture in my mind of it more or less idling, so that the engine and especially power room would be the source of the most noise.
Anyone  got info on the tactical situation at the time of the explosion? Has anyone visited a Pohang and seen the engine and power rooms? Are the diesels encapsulated? 

UltimaRatioRegis said...

Some interesting news out of Seoul this morning.

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