Over-all length

Type of filling

Weight of filling

Total weight

The mine consists of two cylinders, one inside the other. The space between the walls is filled with scrap metal. The outer cylinder is flattened on one side, where there are six sharp projections for attaching the mine to a tree or post. Two clips are provided with fire-proof cord for securing the mine by special rings.

The cylinders are held together at their common base and by a cover at the top. Into one end of the brass moulding, screws a brass cap carrying the striker and the spring. Below this, there is the percussion cap in the holder which is inserted from the side. The lower portion of the moulding takes the detonator and the charge. The open end of the moulding is closed by the plug. The cavity between the brass moulding and the inner cy-linder is filled with powered TNT. The trip-release system consists of a trip-key having a ring at one end, to which the cords are attached.

The key is held by the grooves in the brass cap so that it can move slightly in a direction parallel to the end of the mine. This allows the key to fit into the groove on the striker when in the armed position. A ring guides the cords which are wound on a bobbin, the latter being covered by a hinged flap, held closed by the pin. The pin is used as the safety pin before setting the mine.

There is a special mechanism for detonation the mine, when a cord attached to the trip- release is cut. This meachnism is in the form of a hammer on the cover which is set by attaching the thin cord to the eye and stretching it under sufficient tension to hold the hammer at least 4 mm from the end of the trip-key. When the cord is cut, the hammer drives the trip-key forward, releasing the striker. This hammer is not provided on all B-4 mines.

Figure 236
Mine B-4 - Anti-Personnel Mine