Brooklyn Navy Yard shaped-charge discovery

1880s discovery of the shaped-charge effect with conical copper. Origin story for the RPG/IED case.

A rocket-propelled grenade — some guys studying explosives at Brooklyn Navy Yard in the 1880s found that if you had a conical-shaped piece of copper, and it gets hit with explosives, and the explosives bend that copper and fold it around on itself, you can actually get enough energy that it melts the copper. You can focus that energy. You can have a stream of molten copper shoot out of there. So an RPG, rocket-propelled grenade — if you look at it, it's got this bowl, this front, and it's got the business end with the fins in the back. Up in here, they actually have a piece of copper that's designed in a conical shape.

"The U.S. Navy discovered this in the 1880s at the Brooklyn Navy Yard by mistake, while they were doing some explosives work." Tom's origin story for the shaped charge.

The U.S. Navy discovered this in the 1880s at the Brooklyn Navy Yard, by mistake, while they were doing some explosives work, and they found it would cut through steel. I wish I had one of Doc Edgerton's pictures of a milk drop splash — you have a drop of water come down in a little dish and it goes out in a wave and comes back as a wave, and when the wave comes back you get this big spike of milk. Basically all the copper melts from the energy of the explosion and the mechanical shape — it's called a shaped charge — and you form a jet of molten copper. That will eat through steel of equal thickness to the length of the jet, approximately.