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Topf Mine: Antitank Mine

Topf Mine: Antitank Mine

The Topf Mine, a completely non-metallic, waterproof, antitank mine, consists of a circular body filled with a 12 1/2-pound charge of TNT, a primer plug assembly, and an igniter. The top of the mine is flat, with a fixed pressure plate in the center slightly higher than the surface; a 4 1/2-inch circular recess located in the bottom takes the primer plug and igniter assembly. The outer casing is made of a hard pulp-like material covered with pitch. The mine rests on three glass studs; two of the studs secure a pasteboard carrying handle, while the third, which is sometimes larger than the two others, is used as a filler plug.

The primer plug assembly consists of a glass screw cap and a cylindrical wooden booster holder, the top of which has a deep threaded recess to take the Topf Mine Igniter. A subsidiary igniter socket in the glass cap leads to the booster charge, and is threaded to take a standard igniter.

The Topf Mine Igniter, which is made of glass, has no safety device. It comprises a cylindrical glass body 3 mm thick; a solid glass pressure head, hemispherical in shape and two small glass ampules, one of which contains sodium and potassium as a liquid alloy and the other ethyl nitrate. The ampules are held in position by a black celluloid disc. A thin bakelite detonator well is provided.

The mine is activated by a pressure of at least 330 pounds, which forces the pressure plate down onto the igniter head and thereby breaking the two glass ampules. A flash results, setting off the detonator, booster, and main charge. If a standard igniter is used, the mine must be laid upside down.


Diameter of mine        12 1/2 ins.
Height of mine 5 1/2 ins.
Weight (complete) 20 lbs.
Weight in crate 29 lbs.
Filling TNT
Weight of filling 12 1/2 lbs.
Firing pressure 330 lbs.
Height of igniter (including cap) 3 1/2 ins.
Diameter of igniter body 1 1/2 ins.
Shear pressure of igniter 132 lbs.
Overall height of primer plug assembly 3.1 ins.
Diameter of primer holder 2 1/2 ins.
Diameter of glass cap 4.6 ins.

German: p. 304.9 (May 1, 1945)