26. Electrical S-mine Fuze 40 (Elektrischer S-Minenzünder 40; E.S.Mi.Z. 40)

a. Description. The electrical S-mine fuze 40 (fig. 30) is an instantaneous, mechanical-electrical type having a spring-loaded striker with a ball release. The fuze consists of a cylindrical ebonite case into which is screwed a pressure-fuze mechanism consisting of a spring-loaded striker held by two striker-retaining balls, as in the S-mine fuze 35 (par. 25). A shipping cap is screwed over the top of the fuze during shipment. When the fuze is armed the shipping cap is removed and a three-pronged pressure head is pushed on over the plunger of the fuze. Instead of a percussion cap, a porcelain fitting containing a glass ampoule of orange-colored electrolyte is screwed into the base of the ebonite case. Two electrodes project into the ampoule cavity and are connected to terminals on the top of the ebonite case where they are attached to wire leads. A snike-shaped alu-minum base is screwed onto the bottom of the ebonite fuze housing and is pushed into the ground when the fuze are laid. Individual fuzes measure 8 inches long and 1 1/2 in-ches in diameter without the pressure head.

b. Employment. This fuze is used with a firing bridge (fig. 31) for electrical detonation of the S-mine 35 (par. 85). The fuzes were issued in a chain of 9 fuzes wired together in parallel. Two chains (18 fuzes) are plugged into the terminals of the firing bridge on an S-mine 35 (fig. 31). The purpose of chain fuzes is to increase by 18 times the possibility that a foot soldier would detonate an S-mine. Pressure on any one fuze will detonate the mine.

c. Functioning.

(1)

Pressure on the three-pronged pressure head depresses the plunger until the stri-ker-retaining balls escape into the lower recess, releasing the striker.

(2)

The striker, driven by the striker spring, breaks the glass ampoule.

(3)

The electrolyte in the ampoule sets up an electric current between the electrodes. The current travels through the electric leads to the firing bridge on the S-mine.

(4)

The current sets off the electric detonator which is in the firing bridge and protru-des into the flash tube of the mine.

Figure 30. Electrical S-mine fuze 40.

d. Installing and Arming.

(1)

If the fuze are not already connected, connect the desired number in two chains. The fuzes must be connected in parallel with each other and with the firing bridge within each chain. Each chain may include up to nine fuzes. Individual fuzes should be spaced from 2 to 3 feet apart in the chain.

(2)

Dig a hole to receive the S-mine and firing bridge and make two furrows to accom-modate the lead wires from the fuze chain.

(3)

Test the circuit with a lead tester (plug in the leads to the lead tester, short circuit both terminals of the most distance fuze, and break the circuit again).

(4)

Push the spike of the fuze into the ground until the top of the shipping cap is level with the surface of the ground.

(5)

Unscrew the shipping cap and press the pressure head onto the head of the plun-ger.

(6)

Attach the snap clip of the safety cord the the pull ring of the safety pin.

(7)

Screw the firing bridge onto the S-mine and install the U-clamp.

(8)

Insert the red plug at one end of a chain of fuzes into the red bridge terminal soc-ket. Insert the black plug into the black socket.

(9)

If it is desired to increase the possibility of detonation, place a wooden pressure bar over the pressure heads of serveral fuzes.

(10)

Pull out the safety pin with the safety cord.

Figure 31. Two electrical S-mine fuzes plugged into a fring bridge mounted on an S-mine 35.

e. Neutralizing.

(1)

To neutralizing a chain of electric fuzes, remove the plugs at the end of the chain of fuzes from the sockets in the firing bridge.

(2)

To neutralizing an individual electric fuze, insert a nail into the safety-pin hole and tape it in place.

(3)

Fuzes may also be neutralized by cutting the wire leads on at a time.