This is the drill that cuts 50-foot deep holes into the rock. When 20 or more holes are drilled in a line across the top of the ridge the holes are lined with plastic tubing. This tubing prevents the holes from collapsing.
Special chemicals are carefully measured and put in each hole along with an electronic detonating device. When all is ready, everyone is ordered out of the quarry to a safe location and the blast is set off.