Thermobaric weapons:

What are thermobaric weapons?

The average man is much more familiar with the phenomenon of a volumetric explosion and meets him more often than he thinks. Flour mills, sugar refineries, carpentry workshops, and mines exploded more than once or twice in our country. In a word, rooms in which a suspension (dust) of combustible substances or a mixture of combustible gas and air accumulates. And so familiar to all the explosions of domestic gas in apartments, which destroy entire entrances and even houses? And the explosions of gas tanks, tanks during welding?

These are all phenomena of a volumetric explosion. It creates a mixture of oxygen (air) with a flammable substance, a spark, an explosion.

It is not necessary that gas, gasoline vapors, coal dust should act as a fuel. Ordinary very fine sawdust (for example, from under the grinder), flour, sugar dust, being raised by a stream of air, explode just as well. It’s all about the huge contact area of ​​the substance with oxygen. In this case, the burning process immediately covers a very large amount of matter and in a very short time (of a split second).

However, this does not mean at all that it is possible to grind TNT into a state of dust and a bomb for a volumetric explosion is ready. In conventional explosives of blasting type, energy is transferred and converted into a large number of compressed and highly heated products according to somewhat different laws, and for TNT, for example, on the contrary, the more dense and compressed it is, the better is detonation. And if TNT is turned into dust, but it will give no more effect than wood flour.

So, the principle of a volumetric explosion is clear and not at all complicated. It is necessary to create an aerosol cloud of combustible substance (combustible gas, hydrocarbon fuel vapors, fine dust of any substance capable of burning) mixed with atmospheric air, send a fire (spark) into this cloud and a very powerful explosion will occur. Moreover, the consumption of a substance is several times less than a blasting explosive is needed for an explosion of the same power.

The question is how to create this cloud at the target and how to initiate an explosion, i.e. purely technical and design problems.

The history of thermobaric weapons before its ban

For the first time, American designers of ammunition took up this problem for about a year in 1960. However, for a long time these works did not go beyond the laboratories and individual test explosions.

It was already established that when a bomb containing 10 gallons (approximately 32-33 liters) of ethylene oxide is triggered, a cloud of a fuel-air mixture with a radius of 7.5–8.5 m, up to 3 m high is formed. After 125 milliseconds, this cloud is undermined by several detonators. The resulting shock wave has an overpressure of 2,100,000 Pa on the front. For comparison – to create such a pressure at a distance of 8 meters from the TNT charge, it takes about 200-250 kg. TNT.
At a distance of 3-4 radii, i.e. at a distance of 22.5 -34 m., the pressure in the shock wave rapidly decreases and is already about 100,000 Pa. To destroy the shock wave of the aircraft requires a pressure of 70 000 – 90 000 Pa. Consequently, such a bomb in an explosion can, within a radius of 30-40 meters from the site of the explosion, completely disable the aircraft and the helicopter in the parking lot.

Ethylene oxide, propylene oxide, methane, propyl nitrate, MAPP (a mixture of methyl, acetylene, propadiene and propane) have been tested and are recognized as suitable for use as explosives for volume explosion bombs.

However, the US military became interested in a volume explosion ammunition only during the Vietnam War, when it was necessary to clear the landing sites for helicopters in the jungle as soon as possible. The fact is that the Vietcong very quickly noted a very high degree of dependence of the regular parts of the US Army on the supply of ammunition, food and other material resources. When the Americans dived into the jungle, it was enough to break their supply and evacuation lines (which, in general, is not so difficult to do) to condemn them to a gradual death. The use of helicopters for the supply of material in the jungle was very difficult, and often impossible at all, due to the lack of open spaces suitable for planting. Clearing the jungle for landing only one Iroquois helicopter required from 10 to 26 hours of engineering platoon work, while often in combat everything was decided in the first 1-2 hours.

For the first time, a volume explosion bomb was used in Vietnam in the summer of 1969 specifically to clear the jungle. The effect exceeded all expectations. The Iroquois could carry 2-3 such bombs (right in the cabin). The explosion of one in any jungle created quite suitable landing area.

Very soon, the Americans began to use them to clear the jungle around strongholds, along the lines of communication. At the same time, their very strong impact on the Viet Cong fighters was revealed. The fact is that the resulting cloud of sprayed fuel obeys the usual gas laws and flows inside not hermetically closed structures, including in underground shelters. Thus, the explosion occurs not only outside the structure, as in the explosion of conventional ammunition, but also inside the structure.

The first samples of the volumetric explosion bombs were rather small in size, capacity (up to 10 gallons). After a drop at a relatively small height (30-50 meters), a drag parachute opened, which ensured the stabilization of the bomb and the speed of descent most favorable for the sequence of operations (explosion of the squib and opening of the bomb case, spraying the fuel mixture, scattering of detonators, detonators). From the nose of the bomb down the rope length of 5-7 meters with a sinker. Reducing the tension of the cable when they touch the ground and caused the start of operation operations.

Attempts to create larger-caliber ammunition at the time were unsuccessful due to technical difficulties. A workaround was found – cassette bombs. In one cartridge case there were several bombs of a 32.6 kg caliber explosion. These several bombs were distributed over a certain area, thereby increasing the size of the cloud.

The use of artillery turned out to be inexpedient due to the fact that even large caliber projectiles could carry a comparatively small amount of liquid explosives and most of the projectile weight fell on the thick walls of the projectile body.

An attempt was made to create a munition for making passes in minefields. For this purpose, it was supposed to use the 30 trunnion MLRS “Zuni” (reactive volley fire system). Shells were issued consistently on the same course, but at different distances. It was assumed that one volley would be enough to get a passage in a minefield with a depth of 100m. and a width of 10-12m. However, the excessive dispersion of projectiles buried this idea, although individual explosions showed a good response of pressure-sensitive mine blasters to the shock wave of a volumetric explosion.

The ban on weapons and the abolition of the ban

The further development of the volume explosion ammunition was influenced by the UN resolution of 1976. The fact that the volume explosion ammunition is “inhumane means of warfare, causing excessive human suffering.” Although the work on the ammunition of the volume explosion was significantly slowed down, but continued in a number of countries.

Repeatedly, the volume explosion ammunition was used in various wars of the 80-90s.

So on August 6, 1982, during the war in Lebanon, an Israeli plane dropped such a bomb (of American origin) on an eight-story apartment building. The explosion occurred in the immediate vicinity of the building at the level of 1-2 floors. The building was completely destroyed. About 300 people were killed (mostly not in the building, but in the vicinity of the explosion).

In August 1999, during the period of Chechen aggression against Dagestan, a large-caliber bomb of a volumetric explosion was dropped on the Dagestan aul Tando, where a considerable number of Chechen militants had accumulated. The invaders suffered huge losses. In the following days, the mere appearance of a single (precisely single) attack aircraft SU-25 over any settlement forced the militants to hastily leave the village. There was even a slang term “Tando Effect”.

Approximately by the second half of the eighties – the beginning of the nineties, many countries came to the conclusion that the combat effectiveness of ammunition for a volumetric explosion and the inconsistency of the thesis “inhuman means of warfare that cause excessive suffering of people” (as if humane ways of killing can exist and the degree of suffering or crippled people).

At the international exhibition of weapons, military equipment and ammunition Russian Expo Arms 2002, held July 9-13, 2002. on the test site of the Nizhny Tagil Metal Testing Institute (STIIM) pos. The prospector of the Sverdlovsk region presented and offered for sale two new types of a volume explosion ammunition (the second name is “thermobaric ammunition”), the ODAB-500PMV and 300mm aerial bomb. 9M55S missile for Smerch MLRS.

Detonating space bomb ODAB-500PMV (Fuel-Air Explosion Aircraft Bomb ODAB-500PMV)

TTX bombs ODAB-500PMV
Diameter 50 cm
Length 238 cm
Scope of the stabilizer 68.5 cm
Weight 525 kg
Charge mass 193 kg
Explosive Formulation ZhVV-14

Used with airplanes and helicopters.
Conditions of use:

  • for airplanes the altitude is 200-12000 m. at a speed of 500-1500 km / h.
  • for helicopters, a height of at least 1200 m. at a speed of more than 50 km / h.

It is easy to guess that removing a helicopter from a bomb at the time of its explosion less than 1,200 meters is deadly.

After separation from the carrier at a height of 30-50 m., A deceleration parachute opens, located in the tail of the bomb, and a radio altimeter is activated. At a height of 7-9 meters, an explosion of a charge of normal explosives occurs (in the figure it is highlighted in light orange color). When this occurs, the destruction of the thin-walled bomb shell and the sublimation of liquid explosives (recipe is not given). After 100-140 milliseconds, an initiating detonator, located in a capsule attached to a parachute, explodes and the fuel-air mixture explodes.

300mm. 9M55S missile with thermobaric warhead

This projectile is used by multiple launch rocket systems (MLRS) Tornadoes.

TTX 9M55S projectile
Projectile type jet driven
Gun systems using projectiles MLRS 9K58 “Smerch”
Projectile caliber 300 mm.
Projectile length 760 cm
Projectile weight 800 kg.
Weight of the warhead 280 kg.
Maximum flight range 70km
Minimum firing range 20km
Type of warhead monoblock thermobaric
Dispersion shells in range and course no more than 0.21%

Although the MLRS Smerch allows you to release all of the ammunition (12 shells) in 20 seconds, firing shells with a thermobaric warhead is performed either by single shells or at time intervals that ensure the explosion of the previous projectile before the next projectile approaches the explosion zone.

When the projectile approaches the target on the descending part of the trajectory, the projectile is divided into three parts – the head part, the warhead, and the motor part. At an altitude of 60-70m. the brake parachute is opened and the radio altimeter is activated. Then everything happens the same way as in the bombs.


A question may arise – why have they not yet abandoned conventional explosives, all conventional shells, aerial bombs, and rockets, if the volume of the explosives in the volume of a shock wave is 5–8 times greater than conventional explosives and possess enormous destructive ability?

  • First, the volume explosion ammunition has only one damaging factor – the shock wave. Fragmental, cumulative effect on the purpose they do not possess and can not possess.
  • Secondly, the blasting (i.e., the ability to crush, destroy an obstacle) clouds of the fuel-air mixture is very low, since there is still an explosion of “burning” type, while in very many cases an explosion of “detonation” type and the ability of explosives to crush the shell of a projectile, a destroyed element, etc. is required. Let me explain – with an explosion of the “detonation” type, an object in the explosion zone is destroyed, broken up into pieces, since the rate of formation of explosion products is very high. During an explosion of the “burning” type, an object in the explosion zone, due to the fact that the formation of explosion products occurs more slowly, does not collapse, but is discarded. Its destruction in this case is secondary, i.e. occurs in the process of dropping due to impact with other objects, earth, etc.
  • Thirdly, a large free volume and free oxygen, which is not required for the explosion of conventional explosives (it is contained in the explosive itself in a bound form) is necessary for a volumetric explosion. Those. the phenomenon of a volume explosion is impossible in airless space, in water, in the ground.
  • Fourthly, weather conditions have a great influence on the operation of a volumetric explosion ammunition. With a strong wind, torrential rain, the fuel-air cloud either does not form at all, or it is strongly dissipated.
  • Fifthly, it is impossible and inexpedient to create ammunition for a small-caliber small-bombs explosion (less than 100kg. Bombs and less than 220mm. Projectiles).

There are still many more reasons why ammunition from a volumetric explosion cannot replace conventional ammunition and for which the use of the phenomenon of a volumetric explosion is limited.

Thus, these munitions are not a universal means and the degree of their use depends on what type of ammunition, weapons are expedient and most effective in each particular case.


Like this post? Please share to your friends:
Leave a Reply

;-) :| :x :twisted: :smile: :shock: :sad: :roll: :razz: :oops: :o :mrgreen: :lol: :idea: :grin: :evil: :cry: :cool: :arrow: :???: :?: :!: