thesisThis study was made to determine the value of efficiency studies of various aspects of coal mining. Studies were made of air coursings and the effect of adding or eliminating air courses on fan performance. Mine characteristics were compared under different conditions of fans9 stopped and running, at several blade settings. Power costs were compared for various quantities and circumstances. A detailed study of a hoist indicated that it was underloaded even though it was causing the loaders to be delayed. Steps were taken to correct the defect. The results of this analysis indicate that efficiency studies of mining operations and equipment can save much money for a mining company
