ABSTRACT
An Improvised Explosive Device contains three main components: explosives, an initiator and a firing mechanism. Industrial explosives, such as dynamites or gelatins, have been encountered as well, but with much less frequency. Usually, these have been found in sticks ranging from 100 to 250 grammes each. Chemical delayed time devices are most often based upon sulfuric acid. Mechanical delay devices are based upon metal fatigue. Clasically, when a safety pin is released, mechanical force is applied to a piece of metal holding a striker. Metal fatigue eventually allows the striker to make contact leading to detonation. In practical terms, another terrorist device which was discovered before detonation can be cited as an example of chemical delay. In some cases fragments are a result of a covering around the explosive. For example, if explosives are housed in a metal pipe, that pipe will fragment after detonation of the IE.
