Electricity in Coal Mines

Abstract

IN a paper read by Mr. R. Nelson to the Institution of Electrical Engineers on December 1, a retrospect is given of the use of electricity in coal mines during the last thirty years and also a forecast of what still remains to be done before the mines of Great Britain are fully electrified. In the year 1883, the first electric motor pump was used to pump water from a coal mine ; it was only 1J h.p., but there was then only very little mechanical power used for any purpose below ground. Twenty-five years ago the most disastrous explosion in the history of British mining, namely, that at Senghennydd Colliery, South Wales, had the effect of causing the miners to call for the removal of electricity from the pits. Happily, by the application of systematic stone dusting, a means was found of preventing the spread of an explosion of gas or coal-dust, and thereafter the miners' opposition lessened, at any rate in degree, but it has not yet disappeared. During the last ten years, the coal industry has been greatly assisted by mechanized mining and mechanical methods of coal sorting. These, with normal development in other directions, have resulted in a total of more than two million horse power of motors installed in 1937, half of them being below ground. Accident statistics are touched upon. It is recorded that, taken over ten years, 1927-1936 inclusive, electricity has been responsible for 224 out of 8,656 deaths, or 2J per cent of the total loss of life in the pits. Electricity and compressed air are rival sources of power for the machine cutting of coal. In 1937 seventy per cent of the machine-cut coal was cut by electricity. It is satisfactory to learn that in some of the recently developed South Yorkshire and Nottinghamshire coalfields, their transmission mains are interconnected, a very desirable example of co-operative working. The wider provision of cheap and unlimited current, by the 'grid' for example, would facilitate the use of electricity for all colliery purposes, and would improve the economics of the coal industry by materially assisting mechanical mining. The author concludes with an appeal to electrical engineers to capture the confidence of the miners.