The cap lamp or more accurately ‘Electric Safety Lamp’ is powered by a battery carried on the miner’s belt and a cable running up to the lamp. The lamp may be slotted onto the front of the miner’s helmet by means of a clip or can be detached and used as a flashlight for performing tasks underground. The sight of groups of miners walking through tunnels or being transported to the surface in the ‘cage’ illuminated by the light of their cap lamps, is an enduring image that has come to symbolise our industrial heritage.
The Oldham headlamp was introduced into UK pits during the 1940s. The lamp unit is sealed to prevent gas penetrating the casing thus eliminating the possibility of ignition by electrical sparks. In recent years, manufacturers have made the transition to Light Emitting Diodes (LED bulbs) which together with lithium batteries, provide much brighter illumination for longer periods. Cap lamps are issued from a lamp-room located on the pit-top where units are charged and tested prior to the next shift. The design has found other uses above ground, notably, applications in the fire and rescue service. Since the Falklands War in 1982, the availability of emergency cap lamps aboard Royal Navy ships has become mandatory. Prototypes for battle-grade charging units were trialled at Annesley Colliery.