110. Metal Pressure-Releasing Antilifting Device SM 2 (Entlastungszünder Sofort-zünder aus Metall; E.Z.SM 2)

a. Description. The metal pressure-release antilifting device SM 2 (fig. 134) was formerly designated the E.Z. 44 and consists of a circular, flat, sheet-metal case 5 inches in dia-meter and 1 5/8 inches in height. The case houses a main charge of two semicircular 0.25-pound blocks of explosive, a clock-work mechanism with a spring-loaded striker, and a detonator assembly (Zündersprengkapsel 43). The total weight of this device is 1.2 pounds. The device consists of three parts –

(1)

The pressure-release assembly includes a striker-release plunger that protudes through the top of the case, a plunger spring, and a striker-retaining arm.

(2)

The clockwork mechanism consists of a winding post which protrudes through the top of the case, a special winding key, a rubber washer, a clockwork spring, a rotor wheel, and a grovernor.

(3)

The fuze assembly is composed of a striker, a striker shaft shoulder, a striker spring, a percussion cap, and detonator assembly. An externally located safety bar passes through the striker-release plunger and engages the rotor wheel. An inter-nally located safety pin engages the striker shaft. A rubber waterproofing cap fits over the striker-release plunger.

Figure 134. Metal pressure-release antilifting device SM 2.

b. Employment. This pressure-release antilifting device is employed to activate antitank mines (fig. 135) and may also be used as booby trap.

c. Functioning. As the weight is lifted from the pressure-release plunger and the striker-retaining arm move upward, releasing the spring-loaded striker against the percussion cap and firing the antilifting device.

Figure 135. Pressure-release antilifting device placed under a mine.

d. Installing and Arming.

(1)

Wind the clockwork mechanism fully with the special winding key.

(2)

Place the mine to be activated on the striker-releasing plunger. The weight of the mine moves the striker-release plunger downward and allows the safety bar to ride free of the plunger slot.

(3)

Withdrawn the safety bar with the 58-inch arming cord, freeing the rotor wheel and permitting the clockwork mechanism to function. The coils of the clockwork spring expand and push against the head of the safety pin, disengaging it from the striker. The clockwork spring runs from 1 to 1 1/2 minutes with a loud buzzing sound until it withdrawn the safetypin. When the buzzing stops, the antilifting device is arming.

e. Neutralizing. Once armed, this antilifting device cannot be neutralized. Destroy it in place. See also paragraph 109b.

f. Packing. Five of these pressure-release antilifting devices are packed in a rectangular, wooden box together with two special winding keys and five 58-inch arming cords (fig. 136). A descriptive label is pasted on the lid of the box.

Figure 136. Packing of the pressure-release antilifting device SM 2.