Ordnance

[Genesis]

I dive the U853 quite often off the coast of Rhode Island (US). There is a torpedo in the port forward torpedo tube (torpedo door open) as well as unexploded depth charges and hedge hogs around the sub.

I always wondered how likely it would be for that stuff to explode.

--Matt

Not terribly, but this truly is a game of "you bet your life!"

 

[FredT]

I always wondered how likely it would be for that stuff to explode.
--Matt

Topex and a few other fills were used for some specialized marine munitions, like torpedoes.

TNT is relatively easy to manufacture and cast, as well as being a very stable HE compound, in that it takes a lot to kick it off.

OTOH the priming compounds weren't always so nice.

Be aware that salt water saturated TNT is fairly stable when wet but becomes VERY touchy as it dries out! The salt crystal formation in the matrix of the TNT during the drying process produces pressure points at the corners of the crystals that are almost enough to kick off the charge by themselves. Wet TNT needs to STAY wet until it can be safely detonated!

The powderman who taught me the blasting game once explained that there is always a way to set off explosive compounds, the trick is not being next to it when you do. Being in the water anywhere near (~300 yrds or less for small munitions) an underwater HE blast will generally be fatal due to internal injuries and hemmorages caused by the pressure wave.


FT

 

[pipedope]

One case a diver doing underwater welding set off trapped hydrogen/O2. The blast broke the faceplate of his helmet and knocked him unconscious. He drown before they could get him out of the water.

Explosives are not something to play with.

 

[Bob3]

... unexploded ... hedge hogs around the sub...

My last duty station in the USN was at an ammo dump that had "ship residue" visible at low tide a mile away from where someone had inadvertently dropped a hedgehog on deck.
Even on a good day they're one of the nastier critters out there, & the things are small enough for a diver to carry off with a lift bag.

One case a diver doing underwater welding set off trapped hydrogen/O2

Just another reason to love those Desco pots, they stay intact longer than the diver does.

 

[pipedope]

was a Superlite that had been improperly repaired.
The factory said that if the helmet had been factory repaired it 'probably' would have remained intact.

The Desco is a nice hat. Doesn't absorb nastys like the fiberglass can.

 

[matt_unique]

I was curious as to the danger of the explosives going off underwater as a result of corrosion or other factors. I would definitely not want to be around if someone were stupid enough to try to float one of these things as a souvenir.

--Matt

 

[BigJetDriver]

Too bad the idjitts can't just blow themselves up, without taking innocent bystanders along.

AMEN, BROTHER, AMEN!!

 

[Hobbs]

when doing my military service we learned that safe distance from a swedish handgrenade is 500 meters under water according to our handgrenade instructor.
the reason for us to know that is.. among other things we are supposed to throw handgrenades at divers.....

I dont know if it is true or not, but it makes sence to me...

 

[DA Aquamaster]

I was curious as to the danger of the explosives going off underwater as a result of corrosion or other factors. I would definitely not want to be around if someone were stupid enough to try to float one of these things as a souvenir.

Generally speaking the inbititing devices in a weapon corrode faster than the initiating devices. So there is potentially a period in the corrosion process where the weapon is very sensitive to detonation after the safety devices have corroded away but before the weapon itself as corroded to the point that the detonator will no longer operate.

 

[Hoya97]

A few in here have already touched on this point, but I think it should be emphasized a bit more.

Unlike 99.9 percent of all munitions manufactured, depth charges were NOT intended to destroy a submarine by kinetic energy. In other words, no one ever attempted to destroy the sub by shrapnel. Instead depth charges were meant to kill a sub by concussion. As everyone knows, water isn’t compressible. Hence, the concussion generated by the depth charge was the lethal force, not the shrapnel like a conventional bomb.

Carrying this to the logical next step, if a diver were to pick up a 5 inch shell and subsequently drop it on the deck of the wreck, probably the least worry he would have would be the shrapnel – internal injuries from the concussion alone would kill him/her faster than other, more obvious wounds.

Also as a round corrodes, various areas become saturated at different rates, depending on the amount of corrosion, the place where the corrosion takes place and the type of fill (TNT, Torpex, etc etc) employed. This makes them inherently unstable.

An earlier poster is correct, the most fragile part of any weapon is the fuse – it will corrode first. But just because the fuse is totally gone does not, in any respect, render the round safe to handle – far from it.

As long as people throw a SCUBA cylinder on their backs, people will pick up UXO. However, I think the best way to prevent yourself from becoming a statistic is to make sure everyone in the dive party knows the dangers and agrees not to touch a bloody thing underwater – otherwise, they may have an ‘uplifting experience!’