General

British firing devices, referred to as switches, are used to initiate booby traps or, in some cases, demolition charges. Switches generally operate by pull, pressure, release of pressure, or various combination of these actions. Time or long-delay switches may uti-lize the corrosive reaction of acid with metal, or lead fatigue to achieve the delay. Many types of improvised switches of both electrical and mechanical types may be construc-ted from common materials, but are not dealt with in this publication.

Demolition stores include the more common Detonators, primers, instantaneous fuse, safety fuse, detonating fuse, prepared demolition charges, and military explosives used by the British. These stores are used chiefly in demolition work, or in the preparation of booby trap charges.

Distribution

Switches are ordinarily designated by the "type of action" (pull, pressure, etc.), a "Number" corresponding to the U.S. Navy "Mark", and a Roman numeral "Mark" correspon-ding to the U.S. Navy "Modification".

The designation of demolition stores varies with the particular item, but usually follows the common "Number" and "Mark" system.