(Fig. 1)

This model of the Tellermine, known as the mushroom type presumably because of its cover plate, differs from the 42 model, described in pamphlet No. 9, mainly in the design of the cover plate. The mine like the earlier models, is functioned by pressure applied to a contact igniter or by detonators in the side and base, which may be initiated by "booby trap" device such as the pull igniter Z.Z. 35 or by instantaneous detonating fuze connec-ted to another mine. The igniter used, the T.Mi.Z. 42, is the same as that described for the Tellermine 42 in Pamphlet No. 9 and is inserted below the cover plate.

The mine is 12.3 inches in diameter and has a convex head to which is fitted a three-tier circular cover plate with a maximum diameter of 7.5 inches at the base. The overall height of the mine with the cover plate is 3.6 inches. The weight of the mine with its amatol bursting charge and P.E.T.N./wax exploders is approximately 17 lb. 5 oz. The ex-terior is painted grey and is stencilled on the top, in white, with the abbreviated desig-nations of the mine and igniter, "T.Mi.Pilz 43/T.Mi.Z. 42 13A". The marking "13 A", follow-ing the marking relating to the fuze, indicates the bursting charge to be amatol 50/50.

The steel body consists of two main parts, the charge container and the base plate. The base plate closes the base of the container and is provided with a stepped rim which fits inside the container and is secured by the lower edge of the container being turned in to engage the step. A socket for a detonator and pull igniter is fitted in the base plate. A screwthreaded is formed for the insertion of the pull igniter. The socket is secured by two clips which engage in a slotted flange at its base.

The steel charge container is fitted with a side lifting handle and may have a strip sha-ped to form a loop fitted also on the side. The top of the container slopes upwards to-wards the centre, where it is flat with a groove encircling the fuze hole. Inside the con-tainer below the fuze hole, a steel socket is fitted to receive the igniter. The socket is screwthreaded internally for the assembly of the cover plate and is fitted with a contai-ner at its base to accommondate the main detonator. A socket for the insertion of a de-tonator with a pull igniter is fitted in the side of the container.

The cover plate is attached to the body by a screwthreaded sleeve, protruding from the centre of its base, which is screwed into the igniter socket in the top of the body. A rubber washer seals the joint between the top of the body and the underside of the co-ver plate. The cover plate assembly consists of a light pressed steel circular cover, sha-ped to form three tiers, with a pressure plate secured inside the top tier and a support-ing plate closing the base. The screwed sleeve for the assembly of the cover plate with the body is fitted in the supporting plate.

The diameters of the three tiers of the cover are approximately 7.5 inch at the base, 6.7 inch at the centre, and 5.9 inch at the top, the heights being approximately .3 inch, .5 inch and .4 inch respectively. The pressure plate is held inside the top tier by spot weld-ing at points on its circumference and consists of a mild steel circular plate with a cir-cumferental rim on its underside. The supporting plate is held inside the bottom tier by spot welding, in the same way as the pressure plate, and by the rim at the base of the cover being turned in under a rim on the base of the plate. The plate is of mild steel with a circular corrugation and with a rimmed hole in the centre in which the screwthreaded sleeve is secured by spot welding.

The interior of the body is painted black before filling. The bursting charge consists of 11 to 11.5 lb. of Amatol 50/50 filled from the base to a density of 1.4. An unwrapped explo-der pellet of P.E.T.N./wax 89/11 is inserted to form a surround for each of the detonator holders during the process of filling. The weights and densities of the exploder pellets are:–

Exploder for main detonator 1 1/4 oz. density 1.57

Exploder for side detonator 1 3/4 oz. density 1.56

Exploder for base detonator 1 3/4 oz. density 1.56

The main detonator is attached to the igniter and is described with the igniter, in Pam-phelt No. 9.

The cover plate is removed to insert the igniter with the main detonator. When a load is applied to the cover plate the thin wall of the cover collapses and the pressure plate is forced down on the striker to the igniter, with the result that the shear pin is severed and the fuze functions. The load required to function the mine with the T.Mi.Z. 42 igniter will be approximately the same as for the Tellermine 42, that is, 570 lb.

The mine can also be detonated by pull igniters, which function if an attempt is made to lift the mine before these are disconnected. The pull igniter Z.Z. 35 is described in Pam-phlet No. 8. The position of the sockets for these igniters in the side and base of the mine have been found to vary. Regarding the centre of the lifting handle as twelve o'clock, the side socket may be found between the positions of two and three o'clock or at six o'clock. The base socket is about 4 inches in from the periphery and may be found at positions corresponding to one o'clock or between eight and nine o'clock. There may, of course, the further variations.

Fig. 1