longwall method
Quick Summary
The longwall method is a technique used in underground coal mining where large blocks of coal are extracted in slices. This method involves a working face that extends across the entire width of the coal seam.12
In mechanized longwall operations, machines like shearers or plows cut the coal, which is then loaded onto a conveyor. The roof is supported by hydraulic shields that advance automatically, creating a continuous mining system with high production capacity.1
There are two main systems: the retreating method, where mining moves back towards the main tunnel, and the advancing method, where development and extraction proceed together. This method allows for complete extraction of the coal seam, often resulting in the overlying strata caving in behind the working face. Longwall mining has been used since the 17th century but became significantly more productive with mechanization in the 20th century.123
Ask Britannica AI about this topic
Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.
miningLongwall miningIn the longwall system the ore body is divided into rectangular panels or blocks. In each panel two or more parallel drifts (for ventilation and ore transport) are driven along the opposite long sides to provide access, and at the end of the…
Read MoreIn the longwall system the ore body is divided into rectangular panels or blocks. In each panel two or more parallel drifts (for ventilation and ore transport) are driven along the opposite long sides to provide access, and at the end of the…
Read More
coal miningOrigins of longwall miningThe other principal method of modern mining, longwall mining, had been introduced as early as the 17th century and had found general use by the 19th century, but it had long been less productive than room-and-pillar mining. This began to change in the…
Read MoreThe other principal method of modern mining, longwall mining, had been introduced as early as the 17th century and had found general use by the 19th century, but it had long been less productive than room-and-pillar mining. This began to change in the…
Read More- coal miningLongwall mining
In the longwall mining method, mine development is carried out in such a manner that large blocks of coal, usually 100 to 300 metres wide and 1,000 to 3,000 metres long, are available for complete extraction (see photograph ). A block of coal…
Read MoreIn the longwall mining method, mine development is carried out in such a manner that large blocks of coal, usually 100 to 300 metres wide and 1,000 to 3,000 metres long, are available for complete extraction (see photograph ). A block of coal…
Read More