Shotholes are prepared by powerful drills. The drills may be mounted on mobile platforms, where an unusually thick seam is being worked in two benches; the bulldozer clearing the upper one gives some idea of the height.

• 炮眼预先用功率强大的凿岩机钻好。凿岩机安装在可移动工作平台上--较厚的矿层都分为两个台阶开采，推土机清理上层台阶形成一定的高度。