You can drill holes in the rock. Many useful things made of stone might require holes or something you can make from rock by drilling holes in it. While you may think this would be pretty challenging, the job be.
[pdf] The hydraulic system is the muscle of the crawler mounted drill rig, and its control is a vital part of the overall control system. Hydraulic valves are used to direct the flow of hydraulic fluid to different actuators, such as cylinders and motors.
[pdf] Crawler type deep (water) well drilling rigs adopts full hydraulic control, top drive drives the rotation of drilling tools, and the drilling efficiency is extremely high. The overall layout is reasonable, and it adopts all-ground chassis for transportation, with good maneuverability.
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