What is deep mining?
As most coal seams are too deep for surface mining, underground mining techniques are required.
Of the many different methods of deep coal mining, the most productive is coal face retreat mining, also known as longwall mining.
This involves driving two parallel roadways into the coal seam, typically 280 to 350 metres apart and up to 3,000 metres in length, before connecting both roadways to create a panel of coal. This connecting roadway has state of the art coal cutting equipment installed in it and becomes the coal face which will be cut back towards the main tunnel where the parallel roadways started. This equipment includes hydraulic roof supports, a coal cutting machine (shearer) which cuts from one end of the face to the other like a bacon slicer and a conveyor belt which takes the coal to the surface. As the shearer works along the coal face the powered roof supports advance and the roof is allowed to collapse behind the coal face.
This method of mining coal is used at all of UK Coal’s deep mines.