Bell Pit Mining. Bell pit mining was one of the early methods of underground mining. The name comes from the shape that the mine forms. A long narrow shaft is dug down until it reaches the coal seam.
By 1912, surface mining was conducted with steam shovels designed for coal mining. Methods of extraction ... Coal was mined in America in the early 18th century, and commercial mining started around 1730 in Midlothian, ia.