The Type 99 (Hako-Baku-Rai) mine was a Japanese

anti-tank weapon Anti-tank warfare originated from the need to develop technology and tactics to destroy tanks during World War I. Since the Triple Entente deployed the first tanks in 1916, the German Empire developed the first anti-tank weapons. The first dev ...

used during the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

. It entered service in 1939. Four

magnet A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nic ...

s were attached to the casing made of hemp cloth, along with an external

fuze In military munitions, a fuze (sometimes fuse) is the part of the device that initiates function. In some applications, such as torpedoes, a fuze may be identified by function as the exploder. The relative complexity of even the earliest fuze de ...

. The fuze had a time delay, which enabled it to be used as an anti-tank

hand grenade A grenade is an explosive weapon typically thrown by hand (also called hand grenade), but can also refer to a Shell (projectile), shell (explosive projectile) shot from the muzzle of a rifle (as a rifle grenade) or a grenade launcher. A modern ...

, or a

demolition Demolition (also known as razing, cartage, and wrecking) is the science and engineering in safely and efficiently tearing down of buildings and other artificial structures. Demolition contrasts with deconstruction, which involves taking a ...

charge. Once the safety pin was removed, it was armed, striking the fuze ignited a

powder A powder is a dry, bulk solid composed of many very fine particles that may flow freely when shaken or tilted. Powders are a special sub-class of granular materials, although the terms ''powder'' and '' granular'' are sometimes used to distin ...

delay train Delay composition, also called delay charge or delay train, is a pyrotechnic composition, a sort of pyrotechnic initiator, a mixture of oxidizer and fuel that burns in a slow, constant rate that should not be significantly dependent on temperature a ...

. The mine

detonated 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 s ...

after a five to ten seconds delay, giving enough time for it to be thrown. The mines could be stacked, held together by the magnets for greater effect. When used individually the mine could penetrate approximately 0.75 inches (19 mm) of steel, with two mines stacked it can penetrate 1.25 inches (32 mm) of steel.US Army Field Manual FM 5-31

Specifications

* Length of fuse:

References

* https://web.archive.org/web/20050219144251/http://www.ibiblio.org/hyperwar/Japan/IJA/HB/HB-9-2.html * http://www.inert-ord.net/jap02h/grenades/t99mag/index.html Anti-tank mines Land mines of Japan World War II infantry weapons of Japan Military equipment introduced in the 1930s {{Landmine-stub