Abstract: A method and apparatus for simulating a hand grenade in a training environment. The hand grenade includes dead reckoning to determine location after leaving a thrower. By knowing a location of the thrower and subsequent path after leaving the thrower, the explosion location and simulated damage to targets can be determined. The simulation can determine the effect of obstructions between the explosion location and nearby targets.

Abstract: An actuating device has a cartridge within a fixed casing. A card-like key has a key formation which, during insertion of the key into the cartridge, displaces a finger formation connected to an interference formation, which is then aligned with a gate of a gate member fixed to the casing. The gate allows passage to the interference formation allowing the cartridge to be displaced in unison with the key. An actuating formation on the cartridge is provided to actuate a lock or similar device.