Abstract :
Under the headings of ¿ Design ¿ and ¿ Maintenance, ¿ the author discusses the application of electricity to that particular class of machinery which is used underground in coal mines. Common sources of trouble are described and possible remedies suggested. The first section of the paper discusses various points in the design of switchgear, substations, motors, haulages, and control gear, and the regulations governing the installation of flameproof machinery. The second section emphasizes the necessity of obtaining better-class labour for underground electrical work and recommends the compulsory certification of underground electricians. The advantages of keeping systematic maintenance records are described, and illustrations of typical maintenance charts are given.
