Methods And Results Of Stripmine Reclamation In
Europ. Gemeinsch., 1962. But deep mining for hard coal, at an average depth of 2,500 ft, is expensive and the big power plants are demanding cheaper energy sources. Hence, brown-coal mining is also important for West Germany. In 1960, more than 96 million tons of this material had been hauled from its open-cast mines Pieper, 1962.