Control of roof and prevention of accidents from falls of rock and coal. Suggested roof supports for use at faces in conjunction with mechanical loading. [Comparative evaluations]

This publication describes improved methods of roof support designed to protect face workers in mechanized coal mines against the hazards of falling rock and coal. The various methods of roof support discussed are the pin-jack method, skid-mounted supports, expansion-bolt method, peg timbering, the hitch method, and suspension supports. Detailed drawings and photographs illustrating the various roof-support methods discussed are included.