FUNCTIONING

ARMED CONDITION

FUZES USED WITH

MAX. BODY DIAMETER

OVERALL LENGTH

COLOR

DESCRIPTION:

Around the sides of the fuze body are water entry ports, protected by small spring loaded valves which serves as anti-countermining devices. The water ports lead into a rubber bellows which rests on a shoulder of the fuze body and under the spring hous-ing. Inside, and resting on the upper lip of the spring housing, is a striker sleeve with two holes drilled in it to accomodate two retaining balls, which rest in a groove of the spring-loaded striker and hold it back. Around the striker sleeve is a stationary sleeve having a cut-away top into which the retaining balls can move. On the upper end of the striker is a look sleeve which is held down by a spring and which holds retaining balls in a fixed housing. This device functions when the bomb lands on its tail, prevent-ing the action of the fuze. Through the top of the fuze is a drilled hole into which is fit-ted a safety plunger through which the safety and transit wires are fitted. Below this is a rubber disc which seals the fuze body. In the unarmed position the striker fits down into the detonator shutter and prevents it from moving into line. The detonator shutter is of the rotary type and is attached by a rod to the moving sleeve. Below the detona-tor is the magazone which is screwed into the lower part of the fuze.

OPERATION:

When the bomb is put in the plane the transit wire is removed and a safety wire in-serted. On relese, this wire is pulled and the fuze is armed. Upon entering the water, water begins to fill the bellows entering through the entry ports. As the bellows fills the spring housing is moved up carrying the striker sleeve with it. This moves the striker up out of the detonator shutter and compresses the striker spring. It also moves the shut-ter into line because it is attached to it by means of a small rod. When the bellows have expanded sufficiently to move the striker sleeve to the cut-away portion of the stationary sleeve, the striker cams the retaining balls out and the striker hits the deto-nator and fires the fuze.

REMARKS:

1. This fuze is designed to functioning at a mean depth of 18 feet within the range of 14 to 22 feet.

2. The fuze will not fire on a normal hard surface impact as such an impact causes no movement of the operative mechanism. Should the bomb impact tail first, firing is prevented by the lock sleeve, lightly spring-loaded.

3. Countermining, i.e. firing due to sudden increases in hydrostatic pressure resulting from the explosion of another bomb, is prevented by small spring loaded valves fitted over the water entry ports.

4. The No. 875 fuze is similar to the No. 895, except that more positive detonator shutter action has been provided in the latter. The depth settings of the No. 875 are set by the manufacturer and are designed for different uses, as follows:

Use

No. 875C

Green

30'

600 lb. A.S. Mk I

5. Two issuses of the No. 895 Mk. I type of fuze are at present in service use, with the following depth settings and for use in the following bombs:

No. 895/30 Mk. I

30 ft.

Used in 600 lb. A.S. Mk. I

The designation of the later issue of the No. 895 Mk. I type was altered to include the nominal depth setting. Changes in depth setting are accomplished by the insetion of an additional spring between the top cap of the fuze and the spring housing.