Description
The expression “Improvised Explosives and –Devices” was created at the end of the 60ties of the last century, when global terrorism has started. Difficulties with the logistic support of controlled military and commercial explosive materials, terrorists were looking for inconspicuous resources in the normal trade. According to available “Cook-Books”, “Home made explosives” were produced by terrorists from intermediate products for their objectives.
The presupposition was the availability of those materials, the easy preparation of the explosive materials and properties for a disaster after initiation or ignition.
The knowledge about suitable substances and how to produce such charges are available by literature (internet). Examples are “Terrorist’s Handbook”, “Anarchist Arsenal”, “Black Book”, “Home made Detonators” etc.
Unlike military explosives like TNT, RDX, PETN etc. the range of possible combinations will be very large: May be over 200 examples!
This is also the reason, why there are complications to detect them. Terrorists do not consider very much relative long lasting thermal stability and mechanical sensitivity of the explosive materials. These reduced properties have also consequences for the detection and especially for the disposal process.
Definition of Improvised Explosives (IE) and Improvised Explosive Devices (IED)
Improvised Explosives (IE) are compounds or mixtures of compounds, which have explosive properties and should be relative easily prepared by layman under simple conditions (home made) using freely available chemicals and informations.
Military and commercial explosive materials may be also used in form of simple made charges.
Improvised Explosive Devices (IED) are explosive charges with IE-material in confined or unconfined shape, equipped with a commercial or improvised initiators. The initiator will be ignited by electric or mechanical means.
Such devices react like bombs with a detonation causing a blast wave and fragmentation of the surroundings. If the charge is confined also fragments of the material are formed. There are also examples, where the material is “only” deflagrated, causing also blast waves and fire with large destruction-effects if large amounts of material are involved (Example Sept 11).
It may be important belonging to the demolition output of a charge, that in a distance of more than 1-5 m the pressure wave of a deflagration or detonation will be of the same order. Otherwise the fragments of the confinement will be smaller and more dangerous by detonation.