Switch Booby Trap (Murray) Mk II (Aust)

Switch, booby trap, Combination (Murray) Mk II (Aust.). The switch consists of a hollow cylindrical body made from die-cast metal with a screw cap at one end (missing from this example) inside of which is a steel plunger and spring. It is designed to operate in three positions. 1. Push position, by the application of a weight or blow. 2. Release position, by the displacement of a weight or object. 3. Pull position, by a pull or trip wire or cord. In each of these positions the operation of the trap causes the release of a spring loaded plunger, the pointed lower end of which explodes the cap of an empty .303 cartridge case held in position by a collar engaging the rim of the case and screwing on to the trap body. Exploding of the cap fires a detonator of safety fuse held in position by being clamped between two small lugs cut in the end of the cartridge positioned in the screw cap. The switch can be secreted in various objects which, when removed or pressed, will operate the trap. A pair of mounting lugs are cast into the base of the switch. Used extensively against the Japanese in New Guinea and the island campaigns.

Invented and developed by Major C S Murray, of North Brighton, Victoria in 1943 and submitted to the Army Inventions Directorate. Following further development of this switch, (see REL/02069 for the original Mk I version) Murray was rewarded on 11 October 1950 with a 1,000 pound reward for the invention. The reward was actually paid on 14 February 1951; the invention considered of most value, a mine detector, was invented by Alfred Miller of Caulfield, Victoria, for which he was rewarded 1,500 pounds.