The video shows a shearer operating in underground coal mining. Longwall shearers cut away the face of a coal seam in longwall mining operations by mounting over an armored face conveyor (AFC). They are equipped with cutting drums positioned against the coal seam by ranging arms powered by hydraulic rams. They can weigh more than 100 tons, travel at speeds up to 30 m/min, and cut away slices of coal seams up to 100 cm thick (Wikipedia—Longwall Mining).
Video by Kikki’s Workshop