The Davey Kent DK 920 soil nailing rig consists of a boom, hinge, and mast assembly mounted on a Cat 330 hydraulic excavator. The boom and hinge allow drilling at all mast configurations from vertical to horizontal with a single stroke of 45 ft. The kinematics structure will allow the mast to be turned perpendicular to the body of the excavator and will allow for drilling at up to 30 degrees off this configuration. A hollow spindle motor provides a drill torque of 14,500 ft-lbs.