M54 Thermobaric Weapons (Fuel Air Explosives) -

"The Poor Man's Nuclear Bomb"

By George Paloczi-Horvath

Appropriately dubbed the "poor man's nuclear bomb" by Jane's Missiles and Rockets in July 1998, Fuel Air Explosives (FAE) or thermobaric weapons have been much in the news of late because of Britain's decision in January to investigate this technology for a so-called "bunker buster" infantry weapon. Incorrect reports said that the UK would get an FAE comparable to those used against targets in Grozny with such deadly effect. The British weapon is bring developed by the Defence Procurement Agency (DPA) and is described as an Infantry Anti-Structures Weapon (IASW) system.

UK activity

The Ministry of Defence was anxious to say that it does not have any weapons based on thermobaric munitions in its inventory. "However such weapons exist and it would be irresponsible not to keep developments in this field under review, not least to develop protective measures for our own personnel," the MoD said.

The MoD went on to say that it is currently investigating the possibility of a future purchase of a weapon for use by the infantry in an urban environment designed to incapacitate the occupants of a defended building. This is planned to be a lightweight precision weapon which must be capable of being fired by a single soldier and capable of penetrating the wall of a building rather than having to be fired through a door or window. The plan is to use it at ranges as close as 30 metres "without risk of injury to

either our own troops or civilians nearby," the MoD said. Another report said it might have a 150 metre range and weigh no more than 10 kg.

Industry proposals for such a weapon might involve blast rather than fragmentation effects. There is no funding for such a project which is still "at a very early stage. No decision has been taken on the way ahead," the MoD said. The ministry also added the curious statement for such a devastating technology that "should we decide to buy such a weapon we would, of course, ensure that this was fully in accordance with

international law." The MoD is also anxious to say that it will not buy air-delivered FAEs. It was admitted that research into thermobaric weapons is taking place at an unspecified Defence Evaluation and Research (DERA) site in Kent. This might be at Fort Halstead, though this is not confirmed. DERA has been researching FAEs for several years hence the European and US industry interest in the IASW project,

In service FAEs

FAE bombs have been used against targets in Afghanistan, Lebanon, Chechnya and Vietnam, among other locations. FAEs were also described as "vacuum bombs" because of their effect of drawing out the contents of a building before it collapses.

One internet report says that a typical FAE bomb consists of a container of fuel and two separate explosive charges. After the munition is dropped or fired, the first explosive charge bursts open the container at a predetermined height and disperses the fuel in a cloud that mixes with atmospheric oxygen; the size of the cloud varies with the size of the munition. The cloud of fuel flows around objects and into structures. The second charge then detonates the cloud, creating a massive blast wave. For a frightening demonstration of an FAE explosion on the internet, see the US Naval Air Warfare Center Weapons Division, China Lake, California, page at:

Current Russian FAEs weigh 520 kg in the case of the OPAB-500PM but has a much smaller FAE payload of 193 kg. The 460 kg KAB-500krOD with the RPO-A thermobaric warhead has an FAE payload of 280 kg. This is a daylight only clear weather TV-guided electro-optic bomb with an area of destruction of 1,500 square metres. The OPAB-500PM has a tetranite hypobaric explosive mixture suitable for use on field fortifications or exposed aircraft ramps over 1,799 square metres.

A Russian counterpart to what the British propose to build is the KPB Instrument Design Bureau's Shcmel infantry rocket flame thrower with a thermobaric warhead said to be as effective as a Russian 122mm or 152mm artillery projectile. An FAE

warhead also exists for the trusty RPG-7 rocket launcher while one T-72 tank chassis-based FAE rocket launcher - the TOS-1 - can fire out to a range of 3,500 metres.

Chinese FAE bombs include the NORINCO 600lb FAE cluster bomb which weighs 310 kg which uses three bomblets but can only be used in clear weather or light rain otherwise the FAE effect is weakened. The range over which the aforementioned FAEs explode their blast warheads is indeed comparable to a small very low yield nuclear fission device, but without the radiation effects, hence the description of FAEs as the "poor man's nuclear bomb". The blast wave destroys unreinforced buildings and equipment and kills and injures personnel. The anti-personnel effect of the blast wave is more severe in foxholes, on personnel with body armour, and in enclosed spaces

such as caves, buildings, and bunkers.

FAEs were first developed, and used in Vietnam, by the US. Soviet scientists soon developed their own FAE weapons, which were reportedly used against China in the 1969 border incidents and in Afghanistan. Russian forces now field many third-generation FAE warhead types. Besides classic FAE munitions, Soviet scientists also developed other "enhanced-blast" munitions, notably "reactive-surround" and "slurry-explosive" blast warheads.

Both types of warheads work on the same principle by which explosive is dispersed and mixed with atmospheric oxygen before detonation is completed. Destruction, death, and injury are caused by the blast wave. Reactive-surround warheads are thin-walled containers filled with combustible aluminum and nitrocellulose. Slurry-explosive warheads are a mixture of a high explosive or other explosive solid mixed with a

combustible liquid.

These are just a few technologies in what is becoming a very quickly developing field of new weapons, hence the MoD's understandable interest in either developing a simple IASW or defences against other countries' FAEs.

Disclaimer

The views of the author are his/her own. The UK Defence Forum holds no corporate view on the opinions expressed therein. The Forum exists to enable politicians, industrialists, members of the armed forces, academics and others with an interest in defence and security issues to exchange information and views on the future needs of Britain’s defence. It is operated by a non-partisan, not for profit company.

February 2001

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