Falls of roof continue to be the No. 1 killer of coal miners (Coal Age, Feb. 1975). Since most coal produced underground is by the room and pillar method (97.5% in 1972, Minerals Yearbook 1972), improvements in room and pillar roof control practice would be expected to substantially improve the safety record. In 1969 Congress passed the Coal Mine Health and Safety Ace (PL 91-173) which requires every mine operator to adopt and adequate program for improving roof control systems including a roof control plan suitable to the mine roof conditions and mining method. In order to improve the effectiveness of roof control plans, the Bureau of Mines investigates in this report new tools for their design in room and pillar coal mines.