Low order detonations

It's so satisfying when I see myself causing someone problems. I read the opening of Maria's manuscript and had problems with this scene. So I want to clarify my problem.

It isn't with the explosives used by the good guys. It's the fact that the good guys are blowing up an explosives cache. The problem I'm having is that I'm assuming that a cache would have at least a ton of explosive material, although of unknown quality. The building appears to be located in a community, and probably is a mud-based structure typical of Somalia.

Because I'm assuming a decent size for the cache, I'm assuming there's a lot of collateral damage. Basically the structure with the cache is going to be a crater and the neighboring ones would receive substantial damage.

I guess my reaction as a reader would have been if this was part of a package to make explosives (like fertilizer) or if the material was more flammable rather than explosive.

Best of luck,

Jim Clark-Dawe

All right. I did a LOT of demo work in the Army. Many things to clarify here.

"Low order detonation" - There's a spectrum that goes from deflagration to detonation. I think what you're trying to do is have a high explosive 'go away' with less than full power. One of the untold stories is that explosives will burn completely without detonation, but that is an exceptionally dangerous situation, because the explosive is unbelievably sensitive during combustion. So, your lightning strike could start a fire, which involves the explosives cache. Then, any impact (even throwing a rock at it) would make it explode.

"high explosive" & "low explosive". These are terms for the brisance value of a compound. TNT is 1.0, ANFO (fertilizer) is about .8, C4 is about 1.4. During detonation, the compound will decompose with a characteristic speed. That cannot be changed short of remolding or remixing the compound with others.

The determination of how destructive a detonation is is a combination of the brisance of the compound, the amount of it, and the configuration of the explosive compound. Form the compound into a cone, and it focuses the shock wave into a plasma jet that can cut through a lot more material than an unformed pile.

If I understand what you want to do, it's something like the MOVE scenario (check wikipedia), where a rooftop cache was detonated. It was a row house, so there were some 47 connected houses were destroyed.

Have the cache catch fire and burn for a while. When the entire pile is engulfed, the gasses can't get out of the way fast enough, and a small portion will eventually detonate. Depending on the type of compound you're dealing with, the amount can be roughly calculated.

Good luck!

I don't have a lot of experience with explosives. In Vietnam, we used to carry C-4 around to heat our rations. Without a detonator, it's perfectly safe and burns with a high heat. C-4 is a "high" explosive while gunpowder is a only a fast burning compound. Unless confined, it doesn't explode.

I'd say to use a mixture of the two. Say some high explosive, unconfined, that will be set off by lightning. The pile could contain, let's say, small-arms ammunition. Lightning would set off the C-4, which would burn with a high heat, setting off the cartridges which would go "bang." Released bullets wouldn't have much power but be good pyrotechnically, shooting everywhere. Especially if tracer bullets were included. The result would be a high heat and sporadically exploding cartridges. Not very dangerous except almost on top of them. The escaping bullets would maybe put an eye out at a distance, but not have much power.

Charlie