Amatol

Amatol is a highly explosive material made from a mixture of TNT and ammonium nitrate. The British name originates from the words ammonium and toluene (a raw material of TNT). Similar mixtures (1 part dinitronaphthalene and 7 parts ammonium nitrate) were known as Schneiderite in France. Amatol was used extensively during World War I and World War II, typically as an explosive in military weapons such as aircraft bombs, shells, depth charges, and naval mines. It was eventually replaced with alternative explosives such as composition B, torpex, and tritonal.

Amatol exploits synergy between TNT and ammonium nitrate. TNT has higher explosive velocity and brisance, but is deficient in oxygen. Oxygen deficiency causes black smoke residue from a pure TNT explosion. The oxygen surplus of ammonium nitrate increases the energy release of TNT during detonation. Depending on the ratio of ingredients used, amatol leaves a residue of white or grey smoke after detonation. Amatol has a lower explosive velocity and correspondingly lower brisance than TNT but is cheaper because of the lower cost of ammonium nitrate.

Amatol allowed supplies of TNT to be expanded considerably, with little reduction in the destructive power of the final product, so long as the amount of TNT in the mixture did not fall below 60%. Mixtures containing as little as 20% TNT were for less demanding uses.

TNT is 50% deficient in oxygen. Amatol is oxygen balanced and is therefore more effective than pure TNT when exploding underground or underwater. RDX also has a negative oxygen balance.

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