Composition B (Comp B), also known as Hexotol and Hexolite (among others), is a high

explosive An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An ex ...

consisting of castable mixtures of

RDX RDX (Research Department Explosive or Royal Demolition Explosive) or hexogen, among other names, is an organic compound with the formula (CH2N2O2)3. It is white, odorless, and tasteless, widely used as an explosive. Chemically, it is classified ...

and TNT. It is used as the main explosive filling in

artillery Artillery consists of ranged weapons that launch Ammunition, munitions far beyond the range and power of infantry firearms. Early artillery development focused on the ability to breach defensive walls and fortifications during sieges, and l ...

projectile A projectile is an object that is propelled by the application of an external force and then moves freely under the influence of gravity and air resistance. Although any objects in motion through space are projectiles, they are commonly found ...

rocket A rocket (from , and so named for its shape) is a vehicle that uses jet propulsion to accelerate without using any surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely ...

land mine A land mine, or landmine, is an explosive weapon often concealed under or camouflaged on the ground, and designed to destroy or disable enemy targets as they pass over or near it. Land mines are divided into two types: anti-tank mines, wh ...

s, hand grenades, and various other munitions. It was also used for the explosive lenses in the first implosion-type

nuclear weapon A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear exp ...

s developed by the United Kingdom and United States.''Atom Bombs: The Top Secret Inside Story of Little Boy and Fat Man'', John Coster-Mullen, 2003Nuclear Weapons FAQ section 8.1.1: The Design of Gadget, Fat Man, and "Joe 1" (RDS-1)
accessed August 10, 2009 The standard proportions of ingredients (by weight) are 59.5% RDX (

detonation velocity Explosive velocity, also known as detonation velocity or velocity of detonation (VoD), is the velocity at which the shock wave front travels through a detonated explosive. Explosive velocities are always higher than the local speed of sound in t ...

of 8,750 m/s) and 39.5% TNT (detonation velocity of 6,900 m/s),

phlegmatized A phlegmatized explosive is an explosive that has had an agent (a phlegmatizer) added to stabilize or desensitize it. Phlegmatizing usually improves the handling properties of an explosive (e.g. when munitions are filled in factories.) Tr ...

with 1%

paraffin wax Paraffin wax (or petroleum wax) is a soft colorless solid derived from petroleum, coal, or oil shale that consists of a mixture of hydrocarbon molecules containing between 20 and 40 carbon atoms. It is solid at room temperature and melting poi ...

. Most commonly it is described as 60/40 RDX/TNT with 1% wax added.

Properties

* Density: 1.65 g/cm³ * Velocity of

detonation Detonation () is a type of combustion involving a supersonic exothermic front accelerating through a medium that eventually drives a shock front propagating directly in front of it. Detonations propagate supersonically through shock waves with ...

: 8,050 m/s

Use

Composition B was extremely common in Western nations' munitions and was the standard explosive filler from early

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

until the early 1950s, when less sensitive explosives such as Composition H6 began to replace it in many weapons. M65 bombs from 1953 containing degraded Composition B were responsible for much of the damage in the 1967 USS ''Forrestal'' fire. Some

NATO The North Atlantic Treaty Organization (NATO ; , OTAN), also called the North Atlantic Alliance, is an intergovernmental organization, intergovernmental Transnationalism, transnational military alliance of 32 Member states of NATO, member s ...

-approved munitions suppliers such as Mecar have continued to use Composition B in their products. Composition B is related to

Cyclotol Cyclotol is an explosive consisting of castable mixtures of RDX and TNT. It is related to the more common Composition B, which is roughly 60% RDX and 40% TNT; various compositions of Cyclotol contain from 65% to 80% RDX. Typical ranges are fr ...

, which has a higher proportion of RDX (up to 75%). IMX-101 is slowly replacing Comp B in US military artillery shells, and IMX-104 in mortar rounds and hand grenades.

Gallery

File:DM41 3.jpg, German DM41 fragmentation hand grenade labelled to indicate a filling of Composition B. File:USMC-100414-M-5241M-001.jpg, M107 projectiles. All are labelled to indicate a filling of "Comp B" and have fuzes fitted. File:US Army Military Engineers working with explosive device - Exercise Talisman Sabre 2011.jpg, A shaped charge munition (marked to indicate a Composition B filling) used for various demolition purposes such as boring a hole for a cratering charge. File:Ford_MUTT_M151A1C_FSN_2320-763-1091_pic1.JPG, The 106mm recoilless rifle

HEAT In thermodynamics, heat is energy in transfer between a thermodynamic system and its surroundings by such mechanisms as thermal conduction, electromagnetic radiation, and friction, which are microscopic in nature, involving sub-atomic, ato ...

shell on the right is marked "Comp B".

References

{{reflist Explosives Trinitrotoluene

Properties

Use

Gallery

See also

References