Modern coal cutting technology

In the past, the longwall method of mining was largely restricted to thin seams, but now it is also used with equal success in medium and thick seams. Seams of up to 3 m in thickness are being mined in a single pass. Thicker seams are mined in layers. The method is being applied in seams of verying gradients from flat to steeply inclined. The method permits almost 100% recovery of coal, instead of the 50 to 80% obtainable in room-and-pillar methods. The coal face, European versus USA systems, development of coal plows, development of shearer loaders, remote controls for mine haulage systems, and the shearers on the market are discussed.