Underground engineering project, cross-section 8×7.5 m, rock hardness F12. bolting rig equipped with Woserld hydraulic rock drill, hole depth 4 m, average drilling time per hole: 2 minutes 30 seconds.
Underground engineering project, cross-section 8×7.5 m, rock hardness F12. bolting rig equipped with Woserld hydraulic rock drill, hole depth 4 m, average drilling time per hole: 2 minutes 30 seconds.