Insensitive High Explosives

Interesting tidbit on nuclear weapons safety and high explosives that are largely non-flammable and difficult to detonate:

"Following the 1966 Palomares B-52 crash and the 1968 Thule Air Base B-52 crash, concerns were raised by accident investigators about the high explosive used in the nuclear devices, which had detonated on impact. Efforts were started to find an explosive that was stable enough to withstand the forces involved in an aircraft accident."

"The Lawrence Livermore National Laboratory developed the 'Susan Test' – a standard test designed to simulate an aircraft accident by squeezing and nipping explosive material between metal surfaces of a test projectile. Following experiments with this device, the Los Alamos National Laboratory developed a new safer type of explosive, called insensitive high explosive (IHE), for use in U.S. nuclear weapons."

"IHE explosives can withstand impacts up to 1,500 feet per second (460 m/s), as opposed to conventional HE, which will detonate at only 100 feet per second (30 m/s)."