Hoover Dam Cable Section

The Hoover Dam was built during the Great Depression, and is a concrete arch-gravity dam in the Black Canyon of the Colorado River.  Once known as the Boulder Dam, the Hoover Dam is located on the border of Nevada and Arizona near Boulder City, Nevada.  It is one of the highest concrete dams ever built and it created the largest man-made reservoir by volume in the United States.  It was constructed between 1931 and 1936, and was dedicated on September 30, 1935 by President Franklin D. Roosevelt.  The project was so massive that a joint venture was formed to bid and construct the dam.  The joint venture was called Six Companies, Inc.  The dam is 726.4 feet tall, and has 3,125,000 cubic yards of concrete and weighs more than 6.6 million tons.  Construction of the dam, power plant, and related works took five years to build and was finished two years ahead of schedule.  The reservoir created (Lake Mead) can hold enough water to cover the entire state of Pennsylvania with water one foot deep.

The item in my collection is a section of the original copper, overhead transmission line that carried electricity from the Hoover Dam to Los Angeles.  The high voltage cable is composed of ten segments that connect with tongue-and-groove joints to form a smooth copper tube 1.4 inches in diameter.  This type HH Hollow Conductor was manufactured by General Cable during the early 1930s, and was designed to transmit 287,500 volts across the Mojave Desert.  The cable is hollow because most of the electricity flows through the outer surface, and the hollow design also dramatically reduced the weight burden on the transmission towers that supported the cable.