"So what happens if you set a LAW on fire?" Topic

So take a standard LAW "fire and forget" disposable anti tank weapon.

It gets dropped in a fire.
Does it go off? Explode?
How long does it take to do so?

…sounds like a question for Mythbusters.

Duck

I don't know, but I can tell you that I once had to go into an AAV that was burning. There was belted and single .50 cal rounds and Mk19 40mm grenades strewn all over the deck. I thought they would be firing off, like in the movies, but they weren't, they were just making kind of a dull popping noise and jumping around like popcorn.

The single rounds and short links on the deck of the track had been forward, where the actual flames were, and they were just sort of snap-crackle-popping away from the fire. The ammo was everywhere, all through the passenger compartment and on the ground around the track, with rounds just hopping around, pretty surreal.

For that matter, we used to pinch off some C4 and light it to heat chow and water up, no explosions.

So, I'm not positive, but I don't think it would do the movie thing and blow up (full force), or launch off somewhere.

V/R,
Jack

Well, ammo can be burned in an incinerator – that's the correct way to dispose of it.

Makes a lot of noise, but it doesn't blow up the incinerator.

"What happens when you drop an LAW in a fire?" A better question would be "how do you explain How did the LAW end up in the fire to the RSM?" He will be most interested in your answer!

Regards Allan

(Not speaking from personal experience… but have been to the RSM's office for a "chat".)

You beat me to it Allan, they make you sign for those things!

Fatman

We weren't signed for them, we had them laying all over the place (AT4s, actually, not M72s) ;)

V/R,
Jack

…pinch off some C4 and light it to heat chow and water up, no explosions.

My father told stories of doing the same thing with plastic explosives in WWII. He said you had to be careful or it would burn a hole through a steel pot helmet!

Yeah, I've seen burning C4. It burns wicked hot and according to my sergeant when we did our mandatory military service back home, they will burn a hole in your mess kit, leaving you to answer very uncomfortable questions.

I do know that as far as Broken Arrow drills went, a nuclear bomb warhead in a fire is at substantial risk of going boom enough to scatter the fissile material thus causing a genuine very bad thing.

Wasn't the LAW tube fairly flimsy? I don't know about the warhead but the fuel for the rocket motor certainly has the desire to burn fairly promiscuously.

McKinstry – Seems plausible that it could add to the intensity of a fire then?

The old M72 that we were issued were constructed out of fiberglass with aluminum and plastic fittings, all of which was sturdy yet "disposable".

regards Allan

Just Jack
I've seen HM Gov' types bitching about the amount of 7.62 ammo bods didn't hand back. If you didn't return a grenade; LAW or mortar round you were issued you had better have a good reason.

Fatman

Totally off topic, but this just reminded me of a case I worked on many years ago (maybe late 1980s). It happened out west somewhere (US, maybe Oklahoma). Two little old ladies, driving along in an old Thunderbird, which breaks down. They park the car in the travel lane, turn off the lights, get out, and start walking ahead to make a call for help from a fast food restaurant up ahead. This happened on what looked to be the outskirts of a larger city, where ever it was. It was early morning, not sun-up yet.

Per their depositions, as they are walking along, one of them hears a big crash, the sound of the semi that came over a small rise and just plowed into their car. Without looking back, the one lady asks the other if she just heard something, the other replies "no" and they continue walking.

Meanwhile, back at the crash site, the T-bird bursts into flames and sets the cab of the semi on fire. The truck driver, relatively uninjured, becomes coherent after a few seconds jumps out of the cab, and runs away from the wreck.

Soon the fire dept. responds. The truck is totally consumed by the fire, and the truck driver begins waving them away from the wreck, explaining that his load is eight 750 pound bombs, all completely engulfed in the fire.

They did violently cook off, causing mostly minor damage to hundreds of homes and businesses (or at least insurance claims of such), a shallow 30 foot crater in the four lane road, and all that was left of the T-bird and semi were chunks of twisted frame, an engine block and some axles.

Maybe the weirdest accident scene and post accident vehicles that I have ever scene (of many thousands). Nobody got hurt, as the nearest and most damaged businesses were closed, and the homes weren't close enough for much blast damage. I believe Ford got sued over some claimed issue, causing the car to break down, but there wasn't nearly enough car left to ever make any determination.

I don't know the mechanism involved in setting off the bombs, but the fire department recorded the detonations, and there was maybe four 4-5 feet (deep) of roadbed blown away in explosions.

I think it's safe to say that the rocket motor would go before the warhead. Exactly what would happen would depend on whether you burned through the side of the rocket casing first, burned away part of the nozzle, etc.

I'd say oh! Look there's a LaW-yer on fire :)
Nothing goes boom like in the movies I've been told yet people get killed as opposed to the hero that stand next the said booms in the movies and don't even get a scratch.
Cheers as I duck from the rounds cooking off in my stew .

Depends on where.

In Springfield, every accident ends with a burst of flames. So I'd say, in Springfield, you'd get a huge explosion and a 20 foot crater.

The FBI indexes this site and then visits you at home.

:-)

query Insensitive Munitions on google. DoD tests weapon systems to make sure that fast and slow burning, bullet and frag impact, and dropping do not cause a bad problem. "Bad" being a relative term. In theory a LAW exposed to a fire should just be fuel for the fire and not detonate and trigger a high order explosion.

Fatman,

Sure, and I should have specified that I was talking about ("…AT4s laying all over the place…") in Iraq. My experience was generally that accountability in combat and accountability in garrison were two totally different things. To whit, I think I only saw one AT4 fired in training in a five-year period, but when Iraq occurred they were everywhere.

Having said that, when I came out of Afghanistan I went to Camp Doha, Kuwait, and I was turning my M9 and rounds into a US Army-run armory there. The Army Sgt told me he couldn't take my 9mm ammo, and I asked why not. He stated it was because these weren't the same rounds I'd been issued. I told him he was going to have a hard time collecting the rounds I'd been issued. He said, "what do you mean?" I said, "what do you think we were doing over there?" ;)

V/R,
Jack

Never saw one burn but I would not stand around to find out !!!!

Instructive video:

YouTube link

Talking of Camp Doha, this is what happens when you have a small fire in a locked vehicle in a compound full of vehicles carrying munitions that aren't particularly IM…..

FWIW most early M72 warheads would probably detonate or deflagrate very nicely in a fire. An IM compliant fill was introduced with the M72A7

Based on safety training on explosives (mining) rather than experimentation, it depends on whether the explosive agent catches fire and then just burns or whether it is protected enough from flame (and is confined) to reach a critical temperature and detonate.

In the case of bullets the inertia of the bullet causes the force of the exploding propellant to merely rupture the case.

For those that like to use C4 to cook with, I'm guessing you either let it completely burn away or put it out very carefully. The best and quickest way was to dump a small pile of dirt on it to put it out. If you try to step on it to put it out you better be careful as it tends to not like that.

As for the LAW, get it hot enough and the propellant and the warhead won't like it. Of course, you need to check the data on the launch tube to see if it is "w/ coupler".

Yes, I remember that critical part of prepping to fire the M72 … "w/coupler". Seemed some of first M72s had the annoying habit of the warhead to fall off the rocket while in flight. DOH !!!!

Hey y'all watch this….