A longwall miner (or longwall shearer) is a huge deep mining machine used in underground coal mining. The longwall miner pulls a steel plow or rotating drum back-and-forth across a long face of coal. The sheared coal then falls onto a conveyor for removal from the mine. The longwall miner has a hydraulically operated re-inforced steel canopy which holds up the mines roof and protects the miners. As the longwall miner cuts deeper into the coal seam, the shield advances allowing the unsupported roof to collapse behind the cut, often causing subsidence above ground. A typical longwall miner can have a capacity of up to 2,000 tons of coal per hour.

To view a photo of a longwall miner see:

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