(We Think) It's a bomb - Nuclear (But it's not)

[old medic]

https://www.theguardian.com/world/2016/nov/04/canada-lost-nuke-found-cold-war-bomb

Diver may have found 'lost nuke' missing since cold war off Canada coast
04 Nov 2016

The Canadian navy will be heading to the coast of British Columbia to investigate claims that a diver may have come across “the lost nuke” – a Mark IV bomb that went missing after an American B-36 bomber crashed in the region during the cold war.

Diver Sean Smyrichinsky was wrapping up a day of diving near Haida Gwaii, an archipelago 80km west of the coast of British Columbia, when he stumbled across what may be the remains of the world’s first known “broken arrow”

..............

Continues at the link above.

- mod edit to thread title to reflect results of probe -

 

[SeaKingTacco]

I suspect things just got exciting down at dockyard, Esquimalt.

And probably in a few places in the US, too.

 

[Brad Sallows]

Both reports I've read stated the US claimed it was a dummy capsule, not a bomb.

 

[SeaKingTacco]

Both reports I've read stated the US claimed it was a dummy capsule, not a bomb.

There seems to be some ambiguity about whether there were (conventional) explosive charges on this capsule. The USAF claimed in 1950 that the weapon was jettisoned and conventionally detetonated from the B36 in question. If this is the same weapon, that did not happen.

I agree that there is likely no fissile material onboard. That said- if I was the clearance diver making the first approach, what harm would there be in carrying a Geiger counter to make sure?

 

[Good2Golf]

Mk 4's fissile core was in-flight loaded, and most records indicate that the fissile core (if there ever was one) was loaded in the 'bird-cage' (core holder) outside of the weapon itself (standard practice at the time).  The weapon casing (HE 'lens' material, etc...) could be called a dummy, but if it did include the HE material, then 'dummy' is not the most accurate term.  A shell the same form factor as the Mk.4, but filled with concrete?  That would be a dummy.  An unarmed weapon without its plutonium core, well...that's just an unarmed atomic device.  If it truly is an unarmed device, it would be an amazing piece of atomic history.  Remember, the Mk.4 was literally just a slightly refined version of the 'Fat Man' bomb dropped on Nagasaki.

Very interesting, indeed. op:

Regards
G2G

 

[SeaKingTacco]

Agreed on all that you have said, G2G.

The interesting thing, when you start looking into this incident, is the lack of agreement in the source material on whether this was a actual mk4 without the fissile core, but with the explosive lens or was it a concrete (dummy) bomb?

I tend to think that, based on the way the USAF rolled in the early Cold War,it makes this an actual weapon, sans core.

Either way- we will know in about two weeks.

 

[Good2Golf]

I tend to think that, based on the way the USAF rolled in the early Cold War,it makes this an actual weapon, sans core.

Agree.  What I've read indicates they placed an inert lead core into the weapon immediately prior to salvoing the weapon.

The history of the B-36 fleet and its operations makes for some riveting reading...those were the airborne equivalents of the growing Soviet and American missile submarine forces that followed about a decade later.

It will be very interesting to see what the RCN (and assuming a few USAF/USN pers as well) come up with in the coming weeks.

Regards
G2G

 

[Rifleman62]

Saw this years ago: https://www.youtube.com/watch?v=piDEE80nfgo

Inside a B-36 https://www.youtube.com/watch?v=wCu9MEwcaCQ

 

[Retired AF Guy]

Jettisoned nuclear bombs are not the only WMD laying off the B.C. coast.

During WWII, Canada used Grosse-Ile (off Quebec City) for the development of bacteriological warfare agents, including anthrax. When the war ended all the agents were placed in canisters, loaded on a train and shipped out west, whereupon most of the canisters were dumped in the Pacific Ocean.

I say "most" because apparently, between Grosse-Ile and the west coast, a couple canisters went missing. It was never determined whether they were actually missing or it was just an accounting error.

So down there somewhere, besides the nuclear bomb there are a whole bunch of canisters full of BW agents also waiting to be discovered.

 

[Old Sweat]

Agreed on all that you have said, G2G.

The interesting thing, when you start looking into this incident, is the lack of agreement in the source material on whether this was a actual mk4 without the fissile core, but with the explosive lens or was it a concrete (dummy) bomb?

I tend to think that, based on the way the USAF rolled in the early Cold War,it makes this an actual weapon, sans core.

Either way- we will know in about two weeks.

The account of the incident on pp 167-168 of Eric Schlosser: Command and Control: Nuclear Weapons, the Damascus Accident and the illusion of Safety, New York, 2013 suggests the device was a real weapon, but with the nuclear core removed. The crew jettisoned the device as the aircraft was descending and "its high explosives detonated three thousand feet above the water, and a bright flash lit the night sky."

 

[Good2Golf]

...the crew jettisoned the device as the aircraft was descending and "its high explosives detonated three thousand feet above the water, and a bright flash lit the night sky."

...or not, potentially.  :nod:

 

[SeaKingTacco]

I got a feeling that the crew bs'd the part about the weapon detonating. They may have figured they were in enough trouble already and did not want add a Broken Arrow to the pile.

From the CBC article, the divers's description tracks pretty well with the explosive lens that would go with this type of bomb, what little I know about nuclear weapons.

It would be a lot of fun to be up on that EOD call!

 

[Old Sweat]

SKT,

I had the same feeling. The description fits an implosion-triggered device. The question may be how large are the individual lens that would compress the core to a super-critical mass. (Every once in a while I get to use the knowledge from the three nuclear target analysis courses, two Canadian and one Brit, I took as a subaltern in the early sixties.) In theory they would all fire at exactly the same time and that should have produced an air burst, but the story suggests no detonation(s.)

 

[jollyjacktar]

It did state in the story I read yesterday that the navy would be responding to the area with a vessel in a couple of weeks time.  Which would suggest to me that it may indeed a practice load of some sort.  Or they're just saying a couple of weeks so not to panic the masses. 

 

[old medic]

http://vancouversun.com/news/local-news/canadian-army-interested-in-old-nuke-that-may-have-been-found-off-haida-gwaii

 

[Rifleman62]

IMHO, if it really is a nuc, the USAF would be swarming the area now. And/or someone in the Pentagon is deep into research trying to ascertain if it really is a nuc. I don't think the Historical Research Agency at Maxwell AFB, AL would have the info on the actual load.

Years ago I did some research for a Texas Vietnam era Vet for a pension and contacted the USAF Safety Center. He was in a KC-135 transiting from Alaska, that landed in Edm. The aircraft was was so damaged from the decompression that it was written off. One airman pax was killed. The fellow I was assisting finally got his documented proof of the incident and thus got a pension.

 

[Good2Golf]

I'm fairly confident the USAF has maintained a solid file on their first broken arrow. 

As SKT noted, the dawn of the Cold War was not a time that they were likely carting around concrete.  There is much on the record to note that it was an operable weapon that either had not been armed, or had been armed but safed prior to the captain salvoing the de-activated device into the ocean.

I surmise that the USAF isn't in a rush because they got what they wanted from the crash site in 1953, and know that the only thing left, even if divergent from the original crew's account, is a waterlogged device with several hundred pounds of RDX/TNT.  An EOD challenge, yes, but by all reasonable accounts, no longer a nuclear/radioactive concern.

:2c:

Regards
G2G

 

[Old Sweat]

I'm fairly confident the USAF has maintained a solid file on their first broken arrow. 

As SKT noted, the dawn of the Cold War was not a time that they were likely carting around concrete.  There is much on the record to note that it was an operable weapon that either had not been armed, or had been armed but safed prior to the captain salvoing the de-activated device into the ocean.

I surmise that the USAF isn't in a rush because they got what they wanted from the crash site in 1953, and know that the only thing left, even if divergent from the original crew's account, is a waterlogged device with several hundred pounds of RDX/TNT.  An EOD challenge, yes, but by all reasonable accounts, no longer a nuclear/radioactive concern.

:2c:

Regards
G2G

PP 168-170 of the same source I cited above states the Mk IV bomb (the same type in the above incident,) in a report of a major accident at what is now Travis AFB, CA, contained five thousand pounds of high explosives. I believe on training and administrative missions, the nuclear core was transported separately.

 

[Good2Golf]

PP 168-170 of the same source I cited above states the Mk IV bomb (the same type in the above incident,) in a report of a major accident at what is now Travis AFB, CA, contained five thousand pounds of high explosives. I believe on training and administrative missions, the nuclear core was transported separately.

That sounds right, OS.  I should have used thousands in pace of hundreds.  About half the 10,299-10,900 lbs of a Mk.4 was supposed to have been the HE compression charge(s).

 

[Stoker]

I'm surprised nobody mentioned the nuke lost just outside Savannah Georgia in 58. It was a Mark 15 bomb with radioactive material. Never was found and still there to this day.