117. Spherical Drifting Mine 41 (Kugeltreibmine 41; K.Tr.Mi. 41)

a. Description. The spherical drifting mine 41 (fig. 148) is an oval spheriod consisting of steel halves joined together by a horizontal weld and a strip on the inside of the body. A steel collar, which acts as a stand, is tack-welded onto the bottom of the mine. The col-lar has four horizontal slots in the top so water can pass freely around the mine, thus preventing an air-lock when the mine is placed in water. A 5-foot, telescopc contact rod with antennae at the top is mounted in a central tube. Surrounding the telescopic con-tact rod is a wooden stabilizing float which fits into a recess on the top of the mine in the un-armed position. Internally, the mine consists of a buoyancy chamber, a main charge cavity, and four buoyancy-adjustment compartments closed by aluminum plugs. The buoyancy-adjustment compartments contain steel pellets used to adjust the depth at which the mine is to float. An ignition tube, containing a clockwork delay mechanism, detonator, booster charge, and battery, is connected by insulated wire leads to the cen-tral contact rod tube, at the brass contact ring. The main charge cavity contains a main charge of 25.5 pounds of explosive. The total weight of the mine is 76 pounds. The hori-zontal diameter of the mine is 1 foot 3 inches and it has a height of 1 foot 5 inches. When the mine is armed, the height from the bottom of the mine to the top of the teles-copic contact rod is 6 feet 7 1/2 inches.

b. Employment. This mine is designed to damage pontons, ponton-bridge super-struc-ture, bridge piers, and low-level bridges. It is launched upstream of the objective and allowed to drift until fired by contact with the objective. It may also be used as an anti-tank mine.

c. Functioning.

(1)

When the mine is floated, water dissolved the soluble plug at the base of the teles-copic contact-rod case, freeing the telescopic contact rod, which is spring-loaded.

(2)

As the mine sinks below the surface of the water, the wooden stabilizing float, at-tached to the telescopic contact-rod case, causes the telescopic contact rod to extend to its full 5-foot lenght. The wooden stabilizing float also keeps the mine upright.

(3)

When an object it, the telescopic contact rod touches the brass contact ring and completes the firing circuit, detonating the mine.

Note. A small clockwork delay mechanism in the fuze case can be regulated so the mine will detonate after any set time up to 6 days, even if the rod is not deflected. If the rod is deflected before the set time, the clockwork delay mechanism will be short-circuited, and the mine will fire.

d. Installing and Arming. Place the mine in the water and remove the safety pin. When the soluble plug dissolves, the mine arms itself as described in c (2) above.

e. Neutralizing. There is no way to neutralizing this mine. It is best to explode it either by small arms fire or by a rocket launcher directed at the antennae. Another method is to stretch a rope or wire across the stream downstream from the mine so that the mine will drift into it. If a bridge or other vital installation is threatened by a mine which is lodged against it but still afloat, a line may be attached to one of the carrying handles and the mine towed very gently, from a distance of at least 1000 yards, to a suitable demolition site.

f. Packing. The mines are packed and shipped individually. Fuzes are packed in contai-ners, separate from the mines.

Figure 148. Spherical drifting mine 41.