Tuesday, February 16, 2010

The Longest Bridge In USA

The Longest Bridge in USA - Lake Pontchartrain Causeway

The Longest Bridge in USA and the world  is Lake Pontchartrain Causeway, a 23 3/4-mile causeway spans Lake Pontchartrain, and a great cantilever bridge rises over the Mississippi at New Orleans.

Longest Bridge in USA - Lake Pontchartrain Causeway

This Longest Bridge in America consists of two parallel bridges that are the longest bridges in the world by total length. These parallel bridges cross Lake Pontchartrain in southern Louisiana. The longer of the two bridges is 23.87 miles (38.42 km) long. The bridges are supported by over 9,000 concrete pilings. These two longest bridges feature bascule spans over the navigation channel 8 miles (13 km) south of the north shore. The southern terminus of the Causeway is in Metairie, Louisiana, a suburb of New Orleans. The northern terminus is at Mandeville, Louisiana.

Longest Bridge in USA - Lake Pontchartrain Causeway
The 24-mi. toll causeway across Lake Pontchartrain in New Orleans was opened for traffic on August 30, four months ahead of schedule. This Longest Bridge Constructed of precast, prestressed concrete, the two-lane causeway is 16 ft. above the lake. It is straight and level from end to end except for three 25-ft. humps, to allow passage of small boats, and two double-leaf bascule spans of 75-ft. clearance for larger craft. The $27,600,000 causeway was constructed of 2,243 bents, 56 ft. apart. Precast deck slabs, each weighting 185 tons, were transported from shore by barge and were lifted into position on the bents by floating cranes. The two piles of the bents are hollow, prestressed-concrete cylinders, 54 in. in diameter and 90 ft. long.

Longest Bridge in USA - Lake Pontchartrain Causeway

More on Longest Bridges


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