Underground Mining

There are 5 different types of underground mining. These include Drift, Shaft, Room and Pillar, Continuous, and Long wall. Drift mining is possible where the coal seam intersects the surface. The mine enters the seam in a horizontal direction following the coal. An advantage of drift mining is that it's much cheaper than other methods. A disadvantage is that it's not the safest way to mine as the tunnels may collapse killing and trapping miners. Shaft mining is a common method accessing a coal seam in which elevators provide access to mines. The shaft mines in West Virginia are commonly deeper than 1,000 feet below the surface. One advantage of shaft mining is that it's easy to cover the pit after it's done. A disadvantage is it's the deepest form of underground mining, so it's very unsafe. In room and pillar mining, nearly half the coal is left behind to support the mine roof. Pillars can squeeze putting pressure on adjacent pillars leading to roof collapses. In room and pillar mining, roof falls are a constant danger. An advantage of room and pillar mining is that most of the work place is completely flat. A disadvantage is very dangerous health conditions. In continuous mining, machines can be used with drift or room and pillar mines. Varieties of continuous mining machines have been in use since the 1940's. An advantage of continuous mining is that there are many different types of machines to get the job done. A disadvantage is the constant drilling and blasting of the walls could cause many collapses. Long wall mining is highly efficient. Once the coal is removed, the machine allows the roof to fall behind it. Long wall mines extract much more of the coal. An advantage of long wall mining is that there is a better resource recovery. A disadvantage is disruption of ecosystems and loss of stream and wetland functions.