Transmission and distribution of electricity to mines

With the more general recognition of the advantages and economies to be obtained by the electrification of the surface plant and, where mining conditions permit, the underground machinery at collieries, there is likely to be a big increase in the consumption of electricity in the mining industry after the war. In the South Wales coalfield, where approximately 16% of the total output of the United Kingdom is raised, the transmission and distribution of electricity introduces special problems owing to the hilly nature of the country. To enable some idea of the potential demand at collieries to be obtained, the load for, a typical group of collieries is analysed. Some notes are included on the choice of switchgear for collieries and on the influence on this choice of the proposed amendments to the Regulations for the Use of Electricity in Mines. Information is given regarding the damage to transmission towers during the ice storm of 1940, and a proposal is made to amend the Regulations of the Electricity Commissioners governing ice-loading for conductors. A new design of cross-arm for a single-circuit 33-kV overhead line is illustrated. Recommendations are made for the standardization of equipment required for the electrification of collieries.