144. General.

Most German mine clearing equipment is similar to that constructed by the Soviet (TM 5-223A) and falls into two general groups – mechanical devices and explosive devices. Me-chanical devices for mine clearing consists primarily of drags and grapnels for clearing mines laid with trip wires, and tank-mounted rollers (par. 145) for detonating mines which have pressure fuzes. Most of the drags and grapnels are field-expedient devices.

145. Mine Roller 3001 (Minenräumgerät 3001)

a. Description.

(1)

The mine roller 3001 consists of roller assemblies mounted on the forward ends of two steel arms. The arms are about 10 feet long and are independently mounted by a torsion-spring connection to the front of a tank, so they will project forward. Each roller assembly has three identical rollers and weighs about 1 1/2 tons. One roller is forward and the other two rollers are located about 3 1/2 feet to the rear. The gap between the rear rollers is covered by the front roller. The rollers are about 2 1/2 feet long and 2 feet in diameter. Each roller is hollow and revoles about a fixed axle. As the roller turns, a planetary gear inside the roller revolves at the midpoint of the axle shaft which drives an unbalanced weight. The gear revolves at approximately eight times the speed of the roller, or at such a speed as to give the weights at least two downward pulsations of the roller for approximately every 12 inches of its travel over the surface of the ground. There are then at least two pul-sations per mine (assuming mines are 12 inches in diameter). The impact effect of these pulsations may be of from 1 to 3 tons. The torsion spring keep all rollers in contact with the uneven surface of the ground with about 250 pounds of pressure on each roller.

(2)

When a mine is exploded, an individual roller is destroyed. It can be easily removed and a spare roller attached in 15 to 20 minutes. Two to four spare rollers are car-ried on the tank.

(3)

Several different types of roller surfaces are used, including smooth, toothed, lug-ged, corrugated, and wavy surface. No one type of roller surface function entirely satisfactorily over snow or sand. The rollers most suitable for universal use are the wavy and the smooth surface types. The main difficulties in the use of this device lie in the replacement of rollers destroyed, and in that only two narrow paths, not a wide path, are cleared through a mine field. The power required to operate the mine roller 3001 is, however, appreciably less than that required for most other mine clearing devices of the tank-mounted type.

b. Effectiveness. A tank can push the two roller assemblies over the ground at 3 to 6 mi-les per hour. The rollers will explode mines equipped with pressure fuzes and buried as deep as 6 inches below the surface. Each roller assembly clears a path approximately 6 feet wide.