Abstract :
Electricity was introduced into collieries during the late 19th Century and grew rapidly from powering small pumps to conveyors and coal cutting equipment. It was quickly realised however, that the introduction of electricity into hazardous areas was also a potential means of igniting methane. It was also recognised that switchgear to be used in coal mines would, in addition to being mechanically robust, require to be flameproof. The author shows how the design of the gate end box enclosure has changed quite dramatically over the years, from the tall rectangular structure of the 1930s to the modern cubic structure. He also shows that modern enclosures have hinged single bolt fixing front covers allowing easy access to the contactor compartment