WW1 DOPP 92 SP 15 GERMAN TIMED FUZE (FUSE)

Double effect fuse, this model was an evolution of the Dopp Z 91, based on the same principles, therefore having a classic percussion system in the tail and a rotating discs time system in the upper cone. The lower disc mobile was engraved with graduations from 1 to 29 seconds, and a Roman cross for the pure impact percussion function.
Entirely made of brass, it had a security pin blocking the concutor of the time system. The same specific arming system of the percussion device (with a powder grain in spite of the classical German stem system). It is not clear whether this is triggered by impact or firing.
German version of a timed and percussion fuze, it is sometimes important that a shell explodes beneath the ground, impact fuzes did not achieve this, also if a shell hits a brick wall exploding on the surface would create less damage than if it past through the wall and exploded on the inside, exploding underground may be useful for collapsing enemy tunnels. Many fuses were developed during WW1.
The time delay is set with an adjustable ring that could be changed according to the calculations by the gun observer . It worked by igniting a ring of a slow burning compound underneath the calibration ring, the time it burnt before detonation was determined by the position of the ring.

A0434