Posted By RichC on November 11, 2009
In a recent forwarded email there were a few excellent “under construction” photos of the bridge being build to bypass the Hoover Dam on U.S. Rt 93. The $160 million dollar project is 900 feet above the Colorado River and will more efficiently links the states of Nevada and Arizona. The two massive concrete arches jut out from the rock faces on each side of the river and are being built from 53 individual 24 foot sections that are cast on-site in order to support the highway. (click photos for larger images)
They are are being lifted into place using an improvised high-wire crane strung between temporary steel pylons. The arches will eventually measure more than 1,000 feet across. At the moment, the structure looks like a traditional suspension bridge. But once the arches are complete, the suspending cables on each side will be removed.
Extra vertical columns will then be installed on the arches to carry the road. The bridge has become known as the Hoover Dam bypass, although it is officially called the Mike O’Callaghan-Pat Tillman Memorial Bridge, after a former governor of Nevada and an American Football player from Arizona who joined the US Army and was killed in Afghanistan. Work on the bridge started in 2005 and should finish next year. An estimated 17,000 cars and trucks will cross it every day.
The dam was started in 1931 and used enough concrete to build a road from New York to San Francisco.The stretch of water it created, Lake Mead, is 110 miles long and took six years to fill. The original road was opened at the same time as the famous dam in 1936.
An extra note: The top of the white band of rock in Lake Mead is the old waterline prior to the drought and development in the Las Vegas area. It is over 100 feet above the current water level.