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Tuesday, February 26, 2008

Millau Viaduct – World's Tallest Bridge !!!


An Engineering Work of Art

To me there are few things more impressive than being on a man-made structure, such as a very tall building or a bridge, and viewing blue sky above and clouds below. Of, course for this to occur the structure has be be rather high and the clouds low.

This is why I was immediately impressed when a friend sent me pictures of the Millau Viaduct, which crosses the valley of the Tarn River valley near the city of Millau in the mountains of southern France.

Normally it is the high mountains that present a challenge to engineers building roads that connect two or more points. However, in case of the Millau Viaduct, the mountain area through which the A75 autoroute, also known as la Méridienne, passes is apparently rather high most of the way until it reaches the Tarn River valley. As can be seen from the picture at the right, one has to traverse a long, winding road down the mountain on one side of the valley and then immediately repeat the process while climbing up the mountain on the other side of the valley. In addition to the kilometers / miles and time added by the trip down into the valley and back up into the mountains, time was also lost in the past to traffic congestion in the town and on the two lane bridge across the Tarn River. It is estimated that the bridge over the valley has shortened the driving distance between the Paris and the Mediterranean coast of France by 100 kilometers (about 62 miles) and, during the summer tourist season, reduced travel time by as much as four hours.

Construction of the bridge was a joint Franco-British project with help from companies in other European countries. Financing for the 394 million Euro (U.S. $524) project was provided by the French construction firm Eiffage. As a result of corporate mergers*, the Eiffage frim includes the firm that built the Eiffel Tower in Paris which, at the time of its completion in 1887, was the tallest structure in the world. This is obviously a company with long experience in being involved with construction of structures of record setting size. British architect Norman Foster designed the bridge, which has come to be viewed both as a work of art as well as a construction marvel, while the French bridge engineer, Dr. Michel Virlogeux, provided the engineering design.

While planning began in the late twentieth century, actual construction did not begin until December 2001 and its 2005 target completion date was achieved a little early when it was formally dedicated on December 14, 2004 and opened to traffic on December 16, 2004.

The Millau Viaduct is an artistic and engineering marvel. It currently holds the record for having the highest piles (the pilers rising from the ground and supporting the bridge from below) of any bridge in the world with its highest being 244.96 meters (803.7 feet) and the highest mast (the pilers rising up from the top of the bridge and holding the suspension cables) which towers 343 meters (1,125 feet) above the roadbed of the bridge. It also has a claim to having the highest roadbed of any bridge in the world with its roadbed reaching 270 meters (885.8 feet) above the river below. However, the roadbed of the Royal Gorge Bridge in Colorado in the United States tops this with its roadbed which towers 1,053 feet (321 meters) above the river below. Based upon height of roadbed, the Royal Gorge Bridge is the highest in the world while based upon mast height, the Millau Viaduct is the highest in the world. Regardless of which is the highest, the Millau Viaduct is the clear winner in terms of length and beauty.

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