any high explosives in fireworks?

I was amused to learn the other day that bang snaps actually employ a tiny amount of silver fulminate, a true detonating high explosive. I also found out that high explosives are used in caps for cap guns, as well as other tiny handheld pyrotechnic devices.

What about bigger fireworks, like the shells launched at professionally-conducted shows? Do any of these use high explosives, or are they all flash powder and the like?

I think that a few are, most likely the ones used at the end for the grand finale. Those can sound like a half stick of TNT going off. Something like a Class B firework. Class C fireworks are the ones you normally find at the side of the road stores. I guess I really should be looking this up but I’m sure someone will shortly, just going from memory here.

The display fireworks you see do not use high explosives. The big bangs come from flash powder tightly and heavily wrapped. The Bang Snaps do use a tiny amount of fulminate, but larger amounts of it are likely to go off if you look at them cross-eyed. You don’t need high explosives to get a big explosion, just enough low explosives like flash powder or gunpowder in a strong container.

I remember reading this. Why are larger amounts more vulnerable to accidental detonation? How does one part of a pile of fulminate know that the rest of the pile even exists?

I don’t know, but I assume it’s similar to nitroglycerin, extremely sensitive unless it’s been dispersed in some matrix as in dynamite.

The molecules at the bottom of the pile can feel the weight of the molecules above them.

Silver fulminate can go off under its own weight.

Okay, but if it’s weight-sensitive, then it wouldn’t matter if the weight is from more silver fulminate, or something else like flash powder, does it? Is “This side up” very important with fireworks? :slight_smile:

In Hatcher’s Handbook, Col Hatcher wrote about determining if ordinary gunpowder would go off if shot while still in the canisters they are shipped in. They set up a shooter about 75 feet away and had him shoot at the cans. The smaller, 1 lb or 5 pound cans, no problem. They started shooting the various sizes available, and when they reached a certain size, 50 or 100 pounds or whatever, the marksman was rewarded by being blown over backwards from the explosion.

They eventually determined it was the compression of the powder from the weight above it.

The Handbook is an excellent read, by the way. The Mythbusters could have learned from it when they tried firing bullets into the air to determine if they dropped at lethal velocity. Hatcher’s crew figured how how to find the bullets and categorize the energy very quickly.


Where do you think they get smart bombs from?