Select Page

Electric Switchgear. Picture Source: David Amos.

Stage 10

Electric Switchgear

Diagonally opposite the pit pony stable are two large white metal boxes. These are electrical switchgear called Gate End Boxes but known in pit terms as panels. They did the same job that an electrical socket does in your house, providing electricity to an appliance, only on a much larger industrial scale.

Bank of panels on ‘s10’s Coalface District’ at Annesley Colliery in 1978. Picture Source: The Coal Authority.

The panels were enclosed in a flameproof enclosure to prevent any electrical sparking coming into contact with any inflammable gases. Safety using electricity underground in coalmines was achieved in two ways;

  • Intrinsically safe circuits
  • Flameproof enclosures

Intrinsically safe systems were low voltage equipment such as signalling equipment, telephones, relays and pilot circuits.

For machinery using heavier electrical currents such as coal cutters, conveyors, lighting etc. flameproof enclosures were used.

Video

Electricity with DC (direct current) motors was introduced in coal-mines at small scale from the 1890’s. By the 1920’s electricity in coal-mines was becoming increasingly common, using AC (alternating current) motors.

Initially, electricity was used to power machinery around the pit bottom area but by the mid 1950’s in was used almost universally underground to power coalface machinery, haulage engines and conveyors. The notable exception to this were colliery steam winding engines and the use of compressed air in gassy coal-mines.

Gradually, from the 1950’s to the 1970’s, colliery steam winding engines were replaced by electric winding engines. As electricity developed, so did the increase in horse power (kilowattage) to power underground machinery.

Eventually, it was distributed around the colliery via high voltage armoured cables (3,300 volts) on ring mains with the voltage being stepped down for different equipment, using transformers.

Underground electrical substation at Silverhill Colliery in the 1950’s. Picture Source: The Coal Authority.

At the coalface, panels were located together in series, on a piece of equipment called a pantechnican.

Trailing cables from the panels fed the various types of electric-powered machinery, such as the shearer (coal cutter) and ripping machines.

As the coalface advanced, the electricity supply had to be extended by means of a process called laying up.

Colliery electrician and apprentice in the 1960’s. Picture Source: The Coal Authority.

The person responsible for maintenance and repair of electrical equipment was the colliery electrician or ‘sparky’ as they were sometimes known.

NCB Apprenticeship Certificate 1979.

Electrical staff at a colliery consisted of an electrical engineer, deputy electrical engineers, shift charge engineers, and colliery electricians. These were highly skilled, apprentice-served craftsman.

Next