INCENDIARY DEVICES Source: Bahrain Ministry of Interior
Enhanced Blast Explosives (EBX). Daisy Cutter (BLU-82) explosion, 12,600 pounds of ammonium nitrate, aluminium powder and polystyrene.
Source: US Air Force
Still taken from video produced by security forces in Bahrain following a raid on an alleged bomb factory. Photo shows modifi ed gas cylinder.
initiation of a crude fl ammable gas device may still result in a high number of casualties.
Source: Twitter
Enhancing with gas In order to clarify any misunderstandings that may arise when one is discussing the eff ects of the addition of fl ammable gas into an IED main charge it is necessary to discuss some of the terminology that is oſt en associated with this subject. If an IED is subsequently found to contain or contained bottled fl ammable gas, the bomb is oſt en termed a gas-enhanced explosive device, but what does this actually mean? The term gas-enhanced would imply
that the explosive characteristics of the device are improved in some way by the addition of this type of fuel. There are actually three types of enhancement that can be associated with an IED consisting of gas and explosives.
1. Explosive enhancement. When an explosive material detonates, a blast pressure wave is produced. This wave consisting of extremely hot expanding gases rolls out from the seat of the explosion, violently pushing, crushing or shattering anything in its path at velocities of up to 9000 m/sec. The terrorist frequently believes that these pressures can be increased by adding fl ammable gas to an explosive main charge.
2. Thermal enhancement. On detonation, explosives produce a high-temperature fi reball oſt en of a very short duration. Flammable gas may have an eff ect on this temperature when incorporated into an IED main charge.
Modifi ed gas bottle allegedly emplaced by anti-government protesters in Bahrain.
3. Fragmentation enhancement. Where metal gas cylinders are used, IED fragmentation eff ects may be improved by the body of the cylinder/bottle fragmenting upon detonation of the explosive charge. Whether used as an enhancement or
Source: Bahrain TV
Still taken from fi lm aired on Bahrain TV allegedly showing an IED based on fl ammable gas being fabricated in the country.
Source: U.S. Navy Naval Museum of Armament and Technology
as a main charge, fl ammable gas is being used around the world. Reporting emerging from Bahrain, currently suggests that anti-government protestors are fabricating IEDs comprising of fl ammable gas cylinders, potentially modifi ed so that the contents can be initiated by radio control. It is likely that fl ammable gas will
China Lake FAE introduction team, South Vietnam, 1970.
increasingly be perceived by extremists to be a substitute for HME where technical and procurement limitations are imposed on them by the security forces. Therefore the theſt of fl ammable gas containers or suspicious purchases should be reported to the security forces at the earliest opportunity. Stocks should be adequately secured and checked on a regular basis. Suppliers should be made aware of the potential threat and encouraged to engage with the security services. This article has deliberately avoided discussing technical details that may assist extremists however, such informa- tion is already widely available within the open-source environment and therefore we must be vigilant and raise an appropriate level of awareness. ❚❙
Boiling Liquid Expanding Vapour Explosion.
John Allison MIExpE MIABTI recently retired from the British Army having served for 24 years in bomb disposal, counter-terrorist search and intelli- gence. He now runs High Threat Protection Ltd.
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