The mine is designed to function by pressure applied to a contact fuze (T.Mi.Z. 35) in the cover plate or by detonators in the side and base which may be initiated by "booby trap" devices (Z.Z. 35) or a length of instantaneous detonating fuze connected to another mine.

The body of the mine containing 11 lb. 6 oz. of T.N.T., is circular with a flat base and a convex head which is fitted with a convex cover plate through the centre of which the fuze protrudes. The sockets and containers for the disturbance initiator devices are situ-ated one in the base and the other in the side. The diameter of the mine is apporximately 13 inches and the height, including the fuze, is 3.9 inches. The mine and cover plate are painted a dull red and the assembly camouflaged with green and brown paint. A lifting handle is fitted at the side. The weight of the complete mine is approximately 20 lb.

The body is made in two main parts, the cylindrical charge container with convex head which is stamped from sheet steel, and the flat steel base plate. Strips for the attach-ment of a hoop are spot welded at eight spaced position around the side of the charge container. The head is shaped at the centre to form a recess for the fuze and the cover plate spring, the base of the recess being closed by the socket for the main detonator container. The socket is fitted with the container at its base and is threaded internally for the closing arrangement. This arrangement consists of a number of washers inserted above the detonator and compressed by a screwed plug with a central flash hole. An adjusting screwed plug is inserted to bear on the first plug and is locked to it by a fixing screw. The second plug carries a rubber sealing ring on its upper surface which is com-pressed by the base of the fuze. The flash hole formed in this upper plug coincides with that in the lower plug and is shaped to form a neck by a reduction in diameter near the top. The socket and container in the side of the body is of a suitable size to take the German type of No. 8 detonator and is screwthreaded for the insertion of a pull igniter (Z.Z. 35). The base plate is shaped to form a step near the circumference. The plate is attached after the mine is filled by turning over the rim of the charge container on to the step formed on the plate. The joint is completed and made watertight by the application of a fusible alloy. The inside of the charge container and of the base plate is coated with black varnish.

The bursting charge is consists of 10 lb. 13 oz. of cast T.N.T. filled in four layers with a density of 1.58. The T.N.T. appears to have been cast in the "creamed" condition, i.e., as a semifluid mass consisting of a suspension of fine crystals which had solidified from the melt before pouring. This method has the advantage of reducing caviation and en-suring a good density.

Three unwrapped recessed exploder pellets of pressed T.N.T. crystals are inserted in the process of filling to form surrounds for the three detonator containers. The pellets have a density of 1.45 and are of the following weights:–

Exploder for main detonator

Exploder for side detonator

Exploder for base detonator

Mines of a later date of filling have a plain cast filling of T.N.T. and exploders of pressed T.N.T. flake.

The cover plate is supported on a spiral spring which is located in the recess in the top of the body. The plate has a central hole, threaded to take the fuze and carries a rubber skirting attached round its tappered periphery by means of a tapered ring secured to the plate by screws. The lower part of the skirting fits over a chamfer formed round the body at the top of the wall and extends down over a part of the cylindrical wall. The skirting is held in this position by a surrounding hoop which is shaped internally to conform with the cylindrical wall and chamfer to the body and is provided with an internal shoulder at the top to engage the flange of the cover plate. The hoop is secured to the body by screws which are inserted through a hole near the upper end of each of the eight strips attach-ed to the body and screwed into the hoop. The lower edge of the hoop has a semi-cir-cular piece cut away at one point to provide access to the detonator holder in the side of the body.

Another type of cover plate met with consists of two superimposed convex plates con-nected at the centre by a threaded fuzehole bush. With this type the rubber skirting is held between the two plates and an outer cover plate is used which fits over the as-sembled cover plate and overlaps the top of the hoop.

Details of the fuze, T.Mi.Z. 35, and the pull igniter Z.Z. 35 are included in this pamphlet. The mine is transported plugged and is fuzed when required. A combined gauge and ad-justing tool is supplied for the purpose of obaiting the correct depth of fuzehole. The depth is dajusting by manypulation of the upper screwed plug in the main detonator socket so that the clearance between the base of the fuze and the upper plug is bet-ween 0.06 and 0.08 inches.

Fig. 1