Frank Crowe, superintendent of construction for the Hoover Dam, had a problem. How could the 3,250,000 cubic yards of concrete (enough to pave a highway 16 feet wide and eight inches thick from San Francisco to New York City) that make up the dam be transported from the mixing stations at the canyon rim to the exact point needed on the dam before the concrete set?
Crowe's solution was a system of overhead cable ways stretching across Black Canyon. Each cable way had a crane and a four- or eight-cubic yard bottom dump bucket for concrete that could travel across the canyon. Altogether there were nine cable ways, but the most interesting were the five cable ways whose towers were mounted on tracks, allowing the cable way's crane to be repositioned with pinpoint accuracy at any point over the dam site. The men who operated these cranes were some of the highest paid workmen on the project, earning $1.25 per hour.
First used to pour concrete on June 6, 1933, six of the original nine cable ways are still used nearly seventy years later in 2001 for maintenance of the structure. They can be seen stretching across the canyon in many photographs of the dam. This was the first cable way system of its kind, and has since been duplicated at countless construction sites.