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Surface Coal Mining
At the Trapper mine, coal seams near the surface are uncovered using large draglines.
In less than a minute a
gigantic machine digs a room-full
with each bite. After the coal is
uncovered and then removed, the
ground is restored, and finally
replanted with the same native
vegetation that was there
before.
Dragline at the Trapper Coal Mine |
Underground Coal Mining
Deeply-buried coal seams can be recovered safely and effectively using the
modern fully-mechanized longwall mining system. Rock above the coal bed is held
up by a line of powerful hydraulic supports, while the longwall mining machine
extracts a thick slice from the full coal seam. After mining each pass, the
supports are moved forward to provide support for another slice, and the rock
subsides behind. This photo is from the Twentymile Mine, which employs nearly
400 Coloradans to mine and ship nearly nine million tons each year.
Longwall Cutting at the Twentymile Mine
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