Description
The Fuze No. 880 Mk II consists of a brass body, bored centrally to house a striker guide and a striker-guide spring, which is located between a shoulder at the top of the striker guide and the top of the shutter holder. The shutter holder is of machined brass, and is threaded into the bottom of the fuze body. It contains a spring-loaded detonator shutter.
The striker guide contains a striker pellet under a double spring load from the two striker springs. An annular groove in the pellet is engaged by three retaining balls, located in holes in the striker guide, and prevented from moving outward by the walls of the shutter holder. Beneath the striker pellet, and loosely fitted to it, is a striker block and striker. A lead delay wire passes through the striker block and the striker guide. A horizontal channel bored in the top of the striker guide contains two spring-loaded locking detents. In the unarmed position, these detents bear against the walls of the fuze body.
The striker guide is held compressed against its spring by an arming pin and by the vertical arming detent. The vertical arming detent, in turn, is held in position by the end of the horizontal arming detent. The horizontal arming detent contains an inertia pin, which engages a hole in the top of the fuze body, preventing the horizontal detent from moving.
Safety during shipment and storage is provided by a threaded safety screw in the top of the fuze body, which prevents accidental removal of the arming pin. In addition, the end of the striker in the unarmed position fits into a blind hole in the detonator shutter and holds the detonator out of alignment.
The Fuze No. 880 is a fatigue-type long delay fuze with delay times designed to vary from min. to 6 hr. at 50° F. The designed delay time is set during the manufacture of the fuze and cannot be altered. The nominal delay time cannot be ascertained from the external appearance of the fuze. At temperatures higher or lower than 50 F., the delay times will vary considerably from those for which the fuzes were designed. At below freezing temperatures the fuze has been known to delay 26 hours before functioning.
The No. 880 Mk I is an earlier model of the Fuze No. 880 Mk II, and is identical to the Mk II, except that the arrangement of the shutter holder is slightly different.
Functioning
No information about functioning.
See Also
Nothing else to see.
Source(s)
OP 1665, British Explosive Ordnance (1946)
