Lead: For centuries engineers have searched for a way to tunnel through the earth to remove obstacles to human progress. In the early 1950s, James Robbins invented the first successful TBM, tunnel boring machine.

Intro.: A Moment in Time with Dan Roberts.

Content: The techniques have been as numerous as they have been clever. As early as 2000 BCE, Egyptians mined mountains for copper and gold by splitting rock heated first by fire, then cooled by water. Absent that ability, excavators were forced to chip away at dirt and rock with hand tools. In the early modern era, explosives such as gunpowder led the way though the tailings or residual rock had to be carted away from the front of the cut. Gunpowder blasts made possible an underground section of a French Mediterranean Sea to Atlantic Ocean canal/waterway system in 1679.

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