As surface coal mining equipment becomes larger, the danger to a driver during a fire emergency is increased due to the greater height of the cab above ground. Also, property damage from fires on the larger equipment can be quite substantial. To help solve this problem, the U.S. Department of Interior's Bureau of Mines has developed automatic fire sensing and suppression systems for engine compartments and fuel storage areas of large, mobile mining equipment.The prototype systems sense the flame and/or heat of a fire, then automatically suppress the fire with a B-C class, dry chemical. The systems can also be manually activated. The first system was developed in the fall and winter of 1972-73, and was successfully demonstrated during in-mine fire tests on a 100-ton-capacity truck. Other systems have been developed and in-mine tested on coal augers and large dozers. Bureau plans call for modification and long-term endurance testing of alternate systems on large drills, shovels, and draglines.