84. Bounding Hollow-Charge Mine 4672 (Hohl-Sprung Mine 4672)

a. Description. The bounding hollow-charge mine (fig. 100) is cylindrical in shape with a cone-shaped top. It consists of an outer case, an inner case, a cone-shaped spacer head, an exposed flash tube, a concrete fragmentation collar, a propelling charge, two primer charges, and a hollo charge, which is the main charge. The outer case is screwed to a wooden base. The inner case contains the concrete fragmentation collar and the main charge. The cone-shaped spacer head is fixed to the top of the main charge with a rubber gasket to waaterproof the joint. In the bottom of the main charge is a fuze well that contains an impact fuze. The impact fuze consists of s striker, a lightly compressed creep spring that holds the striker in place, a percussion cap, and a detonator. The fuze well is closed by a metal cap. In the bottom of the mine, between the inner and outer cases, is the propelling charge, which rests on a celluloid collar. In the bottom of the concrete fragmentation collar are two wells, each with a booster charge, a detonator, a percussion cap, and a delay pellet. The delay pellet rests on the propelling charge. The flash tube contains the main fuze well and is held to the mine by a bracket. The bottom of the flash tube contains a powder train that is fired by a special percussion cap as-sembly at the top of the flash tube. This special percussion cap assembly is fired by the main fuze, which can be a snap fuze 43/I (par. 18) or 43/II (par. 19) or a tilt fuze 43A (par. 38) or 43B (par 39). The mine is 6 1/4 inches in diameter and 11 1/4 inches long. It weighs a total 22 pounds, including 3.5 pounds of explosive.

Figure 100. Bounding hollow-charge mine 4672.

Figure 100. – Continued.

b. Employment. This mine is effective against both vehicles and personnel. It was desig-ned to penetrate 4 inches of armor, and for use in all types of terrain, including deep snow.

c. Functioning.

(1)

Actuating the main fuze releases a spring-loaded striker against the special perus-sion cap assembly.

(2)

The flash produced by the special percussion cap assembly ignites the powder train.

(3)

The powder train fires the propelling charge.

(4)

The propelling charge propels the inner case into the air and, at the same time, fires the delay pellets.

(5)

When the spacer head, which provides the correct "stand off", strikes a solid ob-ject, such as a tank, the inertia of motion of the striker overcomes the light resis-tance of the creep spring, and the striker fires the percussion cap, the detonator, and the main charge.

(6)

If the delay pellets burn through before the mine strikes a solid object, they fire the percussion caps, the detonators, the booster charges, and the main charge.

Note. In both (5) and (6) above there is fragmentation of the concrete fragmentation collar. This fragmentation is of primary importance in (6) which makes the mine an anti-personnel mine, and only of secondary importance in (5) where penetration is the primary effect and makes the mine an antitank mine.

d. Installing and Arming.

(1)

Unscrew the metal cap from the fuze well in the bottom of the main charge; insert an impact fuze, closed end first, into the fuze well; and replace the cap.

(2)

Place the mine in a hole so the tip of the spacer head is flush with the surface of the ground.

(3)

Attach the special percussion cap assembly to the flash tube.

(4)

Screw a snap fuze 43/I or 43/II or a tilt fuze 43A or 43B in the main fuze well.

(5)

Arm the main fuze according to the procedure outlined in chapter 5 for the fuze used.

e. Neutralizing.

(1)

Neutralize the main fuze according to the procedure outlined in chapter 5 for the fuze used.

(2)

Unscrew the main fuze from the flash tube.

(3)

Remove the special percussion cap assembly from the flash tube.

(4)

Search for and neutralize any activating fuzes.

(5)

Lifting the mine.

(6)

Unscrew the metal cap from the fuze well in the bottom of the main charge, remove the impact fuze, and replace the cap.

Figure 101. Packing of bouding hollow-charge mine 4672.

f. Packing. Two mines are packed in an open wooden crate, the wooden bases of the mines forming the ends of the crate (fig. 101). The impact fuzes are packed separately in cartons of 10.