Posted on 12/26/2001 3:46:23 PM PST by pa_dweller
That's the difference between a high explosive and a low explosive - you don't have to confine the high explosive to make it go bang. On the other hand, you do need a detonator. Pentrite is a high explosive - no confinement needed. Fortunately, it isn't enough of a primary explosive that it went up when the perp was trying to light it.
But what do I know? I only taught Demolitions in Special Forces. Just a rank amateur. What I DO know is that this moron's feet and probably lower legs would have gone missing in a big hurry, with the bloody fragments probably striking innocent people and causing serious injuries.
Sounds like life in prison without possibility of parole for the Shoe Bomber! (Oh, let me on that Jury!!!!)
Remember that it only takes a spark to set off either blackpowder or Pyrodex.
That even means static electricity, care must be taken when transferring powder from one container to another as steel and iron and even plastics and glass can cause sparks and set off the powder. The amount of powder in the average powder horn is more than equal to that of an hand grenade so it pays to follow the rules...
You're right about directing the explosion - that's what shaped charges do. For that, one needs a conical hole in the charge, something that grenades lack, but that bazookas possess. Gunpowder lacks the power to be useful in such shaped charges in any case. The good news is, it's not likely the perp's shoe was packed in a suitable way to make a shaped charge - but the amount and type of explosive he apparently had wouldn't have needed any shaping to blow his legs off up to his waist, if not his neck.
That is the legal definition, as opposed to a chemical definition. Even steam is an "explosive" in that it can blow up a boiler if the pressure exceeds the rupture strength.
What I meant when saying that gunpowder "doesn't explode" has to do with the nature of the explosion. In a "deflagration" each granule of powder burns, and ignites its neighbor by means of a thermal effect, and that the pile has been set off is communicated from grain to grain by a thermal effect - each one ignites the next like so many match heads in a matchbook. This process is subsonic.
But in a "detonation" each particle actually explodes, and each granule of an explosive sets off the next one by a shock wave, which is supersonic.
Black powder burns without any such shock wave, making it a "low explosive." Dynamite is a "high explosive." However, some high explosives such as C4, can also burn gracefully without exploding, if you simply ignite them.
Legally, they are all "explosives" but then again so is small arms ammunition, and fireworks such as sparklers and Roman candles that don't explode at all. That wasn't what I meant.
If you pour a mound of black powder on the ground and throw a match on it it will explode.
The BATF has classed it as a Class A explosive because of that very reason.
Modern smokeless gun powder on the other hand is classified as a propellent. Pour a mound of IMR 4046 on the ground and throw a match on it, it will not explode. It will just burn vigirously. Same with handgun powder such as Herc Red Dot.
There have been many people injured because they didn't understand the nature of black powder and in their careless use of it have endangered themselves and those close by.
Remember flight 800? A passenger directly above the center fuel tank with an exploding shoe could be devastating and may well not leave much evidence of the crime. At mid flight the tank isn't full which makes it much more volatile. Being over the ocean much evidence is never recovered or destroyed by the water.
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