Photo courtesy U.S. Department of Defense
When it comes to developing new military weaponry, countries try to keep up with the developments of other countries. The development of tanks during World War I led to anti-tank mines, and anti-personnel mines were developed to prevent enemy armies from moving anti-tank mines.
Anti-tank mines are very similar to their anti-personnel cousins, but are much larger. These mines are pressure activated, but are typically designed so that the footstep of a person won't detonate them. Most anti-tank mines require an applied pressure of 348.33 pounds (158 kg) to 745.16 pounds (338 kg) in order to detonate. Most tanks and other military vehicles apply that kind of pressure. Let's take a closer look at one of these anti-tank mines.
M15 Pressure-operated Blast Mine
All anti-tank mines are blast mines, because the goal of the anti-tank mine is to destroy the tank's tracks and as much of its body as possible. There's no need for a bounding or fragmentation anti-tank mine. The M15 is a circular, steel anti-tank mine that contains a main charge of TNT. It has a diameter of 13.27 inches (337 mm) and a height of 4.92 inches (125 mm). The main component of the M15 is the 22.82 pounds (10.35 kg) of Composition B explosive. Composition B is a mix of TNT and cyclotrimethylene trinitramine (RDX).
Source: U.S. Department of Defense
The M15 is armed by rotating the arming switch so that it is set atop the head of the fuse. The cylindrical fuse is made of iron and is attached to the pressure plate by a copper cover. As a tank rolls over the mine, it pushes down on the pressure plate. Underneath the pressure plate is a Belleville spring with a firing pin affixed to its underside. The firing pin is driven down into the detonator, which detonates and fires the M120 booster charge beneath the fuse, which then sets off the main charge.