Bomb used in

Fuze used with

Over-all length

Width of fuze body

Length of each vane

The fuze consists of a very long body and threebladed steel vanes mounted on a brass cylinder which screws internally onto a brass collar. The setting mechanism consists of a setting key which, when rotating, conveys the rotary movement through the worm wheel and gear to the collar, which has the effect withdrawing the arming spindle from the stri-ker. The long arming spindle is keyed to prevent rotation and is braced along its length. The spindle fits into the striker and prevents the locking balls from moving inwards. The inertia weight fits above the striker and is held by a retainig wedge. The spring is not in compression, except in the armed condition.

The setting key is turned so that the dial indicates the depth of function, 0 - 90 meters. The 0 - 90 meter range corresponds to 0 to 35½ rotations of the vanes, althrough it is impossible for operation of the fuze at less than 9 meters depth in water.

When the fuze is dropped, the vanes are prevented from rotating during flight by a shear wire. On impact with water, the shear wire breaks; the vanes force the pressure plate to move up and fall away.

Also on impact, the inertia weight moves forward against the striker spring, and the wed-ges on the specially shaped base will lodge in the recess provided, thereby preventing the interial weight retracting and effecting compression of the striker spring.

The vanes rotate during water travel to raise the arming spindle. As the spindle passes the locking balls, the balls move inwards to free the striker, which is then forced into the detonator.

Figure 69
Hydrostatic Tail Fuze - "Grand-Daddy"