Modern Marvels

Coal Mines (10x16)

Exibido em:: Abr 02, 2003

Coal--the fuel responsible for more than half the electricity used daily. We unearth the amazing technological advances that have led to today's extremely efficient methods--from ancient techniques to the simplistic bell-pit method, from drift mining, surface mining, and strip mining to modern longwall mining, when a massive machine extracts an entire wall of coal in seconds. We go underground with miners in West Virginia, Pennsylvania, and Wyoming, and also address environmental concerns.