Longwall Mining

Longwall Mining:-

Longwall mining is a highly productive underground coal mining technique.  Longwall mining machines consist of multiple coal shearers mounted on a series of self-advancing hydraulic ceiling supports.  The entire process is mechanized.  Longwall mining machines are about 800 feet (240 meters) in width and 5 to 10 feet (1.5 to 3 meters) tall.  Longwall miners extract "panels" - rectangular blocks of coal as wide as the mining machinery and as long as 12,000 feet (3,650 meters). Massive shearers cut coal from a wall face, which falls onto a conveyor belt for removal.  As a longwall miner advances along a panel, the roof behind the miner's path is allowed to collapse.