McEvoy’s Improved Percussion-Fuse
consists of a fuse-case containing an ordinary spring gun-lock, nipple, and percussion-cap. The hammer of the lock is held back by a vertical rod free to travel in a guide. On top of the rod is a ball held in place lightly by the upward pressure of a spring. In case that the torpedo is struck and tilted over the ball falls from its seat on the rod, the latter is forced up by the spring, releasing the hammer and exploding the percussion-cap.
Friction-Fuses.
Friction-fuses as a rule consist of some arrangement by which an ordinary friction cannon-primer is exploded. This is done by attaching a firing laniard to the friction-bar of the primer and either leaving it free, so as to fire at the will of the operator, or attaching it in such a way that the momentum of a vessel catching it will pull it. McEvoy’s improvement on Singer’s percussion-fuse consists in attaching the laniard of a friction primer to the heavy cover.
Barrel Torpedoes with Friction-Fuses.
Chemical Fuses
Chemical Fuse.
are those in which substances separated until required for action are then brought into contact and unite chemically with an explosive effect.