Purchased power in coal mines

In this paper, the author points out the commercial aspects of purchased power, vs. the isolated plant in the bituminous coal fields of Western Pennsylvania and Eastern Ohio. The adverse conditions affecting the operation of isolated plants and the fundamental causes of high costs of power per ton of coal mines are given, and are contrasted with the advantages to the mine operation of the purchase of power when available. The characteristics of mine power business are briefly described with a view of showing the reasons why central stations can afford to make low rates for this class of business.