12:06 PM

New Scientist:

What sort of explosives do you use now?

There are two types of explosive - low order and high order. Low makes a slow heaving explosion, which pushes more than it shatters. We tend to look for a shattering explosive because we want to instantaneously remove the structural integrity of whatever we’re working on. So we would opt for nitroglycerin or NG-based dynamite. With a steel structure, we use something called a linear-shaped charge that concentrates the force of a high explosive called RDX. For example, it took 80 pounds of shaped charge to bring down two New York gas tanks built with 5 million pounds of steel.