The objective of this U.S. Bureau of Mines contract was to conduct an in-mine test of a rotary water seal and antifrictional ignition spray system for a continuous mining machine. Previous research had shown that water sprays mounted on a longwall shearer drum reduced the likelihood of frictional ignitions. Past efforts to direct water to the drum of a continuous miner failed because a suitable rotary water seal was not available. In 1983, a seal developed by cannings seals ltd. For use on road-heading machines in British mines appeared to have high potential for successful application on continuous miners. A Lee-Norse 265 miner was retrofitted and put into service in May 1987. The machine, after mining in excess of 150,000 tons, was taken out of service in May 1988 without incurring any seal problems. This underground trial demonstrated that there is now a viable water seal for use on continuous miners to provide water to the cutting drum.