ROCKET USED IN

FUNCTIONING

ARMED CONDITION

FUZES USED WITH

ARMING TIME

MAX. BODY DIAMETER

OVERALL LENGTH

8.5"

GENERAL:

The Mk 141 Mod 0 is issued to amphibious groups for use in destroying beach ob-stacles. The fuze is water discriminating and so designed that it will not fire on impact with water but will be actuated by impact with the earth or soft sand, provided the water travel before impact is not more than twenty feet. The water descriminating fea-ture is obtained by use of a copper shear wire. The Mk 141 Mod 0 will replace the Mk 152 in the 7.2" Demolition Rocket (Mk 5 head).

DESCRIPTION:

The fuze was developed from the Bomb Nose Fuze AN-M110A1 and retains the upper body and gear reduction system used in that fuze. To obtain detonator safety, a pivo-ted detonator shutter has been added below the firing pin. The shutter is held in the safe position by the firing pin and when fuze is armed, the shutter is locked in position by a spring loaded detent. The safety block of the bomb fuze has been replaced by the arming hub, an integral extension of the stationary gear which locates the cross shaped striker head in the safe position. The movable gear in the Mk 141 Mod 0 acts to thread the striker assembly forward and out of the fuze body, thus withdrawing the firing pin from the detonator shutter slideway (releasing the shutter to move into the armed po-sition), and moving the striker head away from the arming hub. The striker and firing pin are mounted, by a copper shear wire, in the inner sleeve which forms the threaded hub of the movable gear. The arming wire bracket of the bomb fuze has been retained and, in shipment, a safety wire ties the vanes to this bracket. To insure proper air flow past the fuze vanes, an elongated booster chamber has been added to the fuze. This ca-vity, loaded with tetrly increments, extends the tip of the fuze 6 inches beyond the rocket head. At the lower end of the booster chamber a threaded adapter has been fixed to adapt the 1 1/2 inch diameter fuze to the 2 inch diameter fuze pocket. Two Mk 1 Mod 0 auxiliary boosters are required in the fuze pocket.

OPERATION:

When rocket is fired, the arming wire is pulled, and the vanes are free to rotate. The rotation of the vanes acts through the reduction gears to thread the inner sleeve up in the arming hub and thereby withdrawn the firing pin from the detonator shutter. The shutter is forced across the shutter cavity by its spring and is locked in the armed position by the spring loaded detent. On impact the striker is driven down, shearing the copper shear wire, and fires the detonator - booster lead-in - booster.