During the past 10 years rock bolting has evolved into a systematic method of underground roof, wall, and floor support, which is generally accepted wherever ground can be consolidated economically and efficiently. Although the method was known and used occasionally over a long period of time, apparently acceptance was contingent upon the improvements in drilling and mechanized loading that have taken place just before and concurrent with the development. Rock bolting effects a general improvement in safety by reducing roof-fall accidents, increases efficiency, and makes for conservation in mining.

This paper attempts a logical classification of rock bolts from the standpoint of utilization and provides current criteria for designing and testing installations.