by guest blogger Kristen P. Constant: Today in History- September 30, 1935 - Dedication of Hoover Dam, Boulder City, Nevada. The concrete-arch dam, originally called Boulder Dam, supplied the first U.S. hydroelectric plant to produce over a million kilowatts. Hoover Dam serves Nevada and the Los Angeles area.

Hoover Dam was built at the height of the Depression and provided thousands of jobs for American workers.  To their credit, they completed the dam in less than five years - ahead of schedule and under budget.

Hoover Dam is a curved gravity dam with Lake Mead pushes one one side and Black Canyon on the other, creating large compressive forces. It is reported that there is enough concrete in Hoover Dam (4.5 million cubic yards) to build a two-lane road from Seattle, Washington, to Miami, Florida, or a four-foot-wide sidewalk around the Earth at the Equator. The chemical heat produced by the curing concrete was dissipated by ice water circulating through more than 580 miles of steel pipes embedded in the dam.  It is estimated that if the concrete had been allowed to cool naturally, it would still be warm to the touch!!

See the Engineering Pathway’s educational resources on dam design and construction. or visit the Civil Engineering Education, Materials Engineering Education or the Electrical Engineering Education community sites.

Also on this day in history in 1882, the first U.S. hydroelectric plant went online. Rayon was patented in 1902 and the first nuclear submarine was commissioned in 1954.