A./P. Mine E.P. No. 4 (Obsolete)

Diameter

Height

Weight

Explosive weight

Explosive

Material

Fuze

Description: The Mine E.P. No. 4 consists of three component parts: the outer mine canister, the inner loaded mine case, and the special Fuze Unit No. 1.

The outer canister consists of a cylindrical sheet metal container for the inner loaded case. The outer canister acts as a mortar from which the inner case is projected. A short tube projects from one side of the outer container near the bottom. The instantan-eous fuse passes through this tube to the switch, when the mine is laid. The top of the outer canister is closed by a lid.

The inner loaded mine case contains shrapnel set in concrete around the sides and bottom. In the center of the case are located three sticks of Gelignite, which comprise the main explosive charge. Near one edge of the inner case is located a hole to allow passage of the instantaneous fuse.

The Fuze Unit No. 1 consists of a length of instantaneous fuse. Toward the center of this length of fuse is fixed a charge of black powder, which serves to propel the bomb from the container. A Detonator No. 27 is crimped to one end of the length of fuse. A one-inch length of safety fuse intervenes between the detonator and the instantaneous fuse to provide the necessary delay. The other end of the instantaneous fuse is led through the tube in the base of the outer canister to the initiating switch. The fuze unit is shipped in the bomb, but is not assembled.

Functioning: Operation of the switch initiates the red instantaneous fuse. The red fuse ignites the black powder charge, which blows the inner mine case out of the canis-ter, and then flashes on to ignite the safety fuse delay. The safety fuze allows the bomb to fall back to the ground before detonating.

Use: This mine is a bounding shrapnel mine designed for anti-personnel purposes. When the mine is fired, the bomb jumps from its container, comes to rest of the surface of the ground, and explodes.

Assembly and Arming: Remove the lid from the mine, and withdraw the fuze unit and the inner case. Thread the detonator end of the fuze unit through the hole in the in-ner case. Thread the other end through the hole in the outer canister and draw it all the way through, lowering the inner case gently into the canister. Attach the trip or pressure mechanism to the fuze unit. Charge the bomb with three sticks of Gelignite; insert the detonator into one stick; and replace the lid of the mine.

Neutralization: Cut the red instantaneous fuse at the most convenient place. Neu-tralize the switch. Remove the lid from the outer canister and pull the detonator from the charge. Remove the inner case from the container and unthread the fuze unit.

Remark: Atlhough any British switch may be used with this mine, the switch designed especially for it is the Pressure Switch E.P. No. 1. This switch consists of two steel pla-tes, which are hinged together. The upper plate carries a pressure bar, which, when the plates are forced together, crushes a chemical igniter ampoule contained in a tube on the lower plate. The end of this tube is open and is of suitable diameter to accept in-stantaneous fuse. The fuse is inserted as far as possible, and then crimped in place.