Sunday, July 19, 2009

New York City's Bridges: Queensboro Bridge (2)

A closer look at the Queensboro Bridge on Roosevelt Island. It is a five span truss bridge with long approaches. The center span (over Roosevelt Island) is 630 ft long. The west cantilever span (to Manhattan) is 1182 ft long. The east span (to Queens) is 984 ft long. The side spans are 469 and 459 ft long. The entire bridge including the approaches is 7449 ft long. It is supported on four, 350 ft tall steel towers on stone piers (a tower for the Roosevelt Island Tramway can be seen next to the bridge tower in the photo).

The Queensboro Bridge carries an 80-ft wide double deck roadway, which at one time carried trolleys and trains, but now carries nine traffic lanes and a bicycle path and walkway. It carries about 200,000 vehicles a day but several of the lanes are restricted to automobile traffic. The trolley on the bridge used to stop at Roosevelt Island, but now residents can take the tramway or a subway between Manhattan and Roosevelt Islands.

Maintenance of the bridge was neglected for many years. In the early 1980's a $300 million project was begun to repair the bridge, which was completed on the bridge's centennial. Because of the expense of maintaining this bridge, Mayor Bloomberg tried to transfer ownership to the MTA so that tolls could be collected, but that idea was stopped by Governor Pataki.

The other East River crossings (south of the Queensboro Bridge) were suspension bridges with 1470 ft to 1600 ft main spans. Because Roosevelt Island reduced the span length to the channel width on each side of the island, a cantilever truss bridge with shorter spans could be built. Linderthal (the chief engineer on the project) hired an architect and tried to make the bridge as attractive as possible. It was considered by many to be the height of elegance after it was built. It also greatly expanded the development of Queens. More information on the bridge can be found on a website maintained by Steve Andersen about New York City Roads.
Creative Commons License
New York City's Bridges: Queensboro Bridge 2 by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

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