Building Diversion Tunnels

The most dangerous phase of Hoover Dam's construction was building the diversion tunnels. More

The most dangerous phase of Hoover Dam's construction was building the diversion tunnels, two on each side of the Colorado River. Blasting holes 56 feet in diameter, three-quarters of a mile through the canyon rock, the workers faced a huge engineering challenge along with strict time constraints. Chief Engineer Frank Crowe solved the problem by building a contraption called a drilling jumbo.

AIR DATE 1/18/99