This equipment should be managed by well-qualified workers who are familiar with the safety rules and know how to make use of the machines correctly to avoid dangerous. (drilling underground)Underground, in the coalmine, here are some tools which help miners to output the coal. They are: longwall shearer, boom-type roadheader and coal crusher. The first device is called longwall shearer. It is a mining device, which works below ground, in the so-called mining wall, or in the place where the coal is directly output. It moves using the special conveyor (named scrapers); it does not apply caterpillars (such as boom-type roadheader). The CM driver works such a machine by the remote control. (roof bolter)The 2nd equipment applied underground is called boom-type roadheader. It moves making use of caterpillars and works underground where drills roadways in the mine. Its front part with the tool drills the rock and move forward. The gained coal is transferred at the bottom of the boom-type roadheader.The last machine, which will be introduced in this text, is called coal crusher. It is a tool made use of for crushing coals into smaller parts. There are machines for crushing mineral coal and brown coal, too.