This report contains the results of several related research efforts that were aimed at enhancement of mine power system safety and reliability. The largest single effort was on optimum spares and maintenance scheduling for various components of a mine power system. Two closely related tasks involved calculating the minimum arcing faults that could occur on DC trailing cables and the use of trippable load break switches to clear ground faults. Both of these tasks are concerned with reliable fault clearing to prevent shock and fire hazards. Three other closely related tasks were concerned with aspects of mine power system design--alternate network topologies, optimum voltage selection for mine power systems, and selection of system components. The final task consisted of laboratory tests to ascertain the effects of repetitive, low-level transients on insulation systems.