The Manhattan Bridge is a two-decked suspension bridge that carries automobile, subway and pedestrian traffic over the East River. It connects Flatbush Avenue in Downtown Brooklyn with Canal Street in Chinatown, Manhattan. Because it was conceived after the Brooklyn and Williamsburg Bridges, it was called Bridge No. 3 in its planning phase. The bridge is distinguished by an elaborate stone portal and plaza at its Manhattan end.
The Manhattan Bridge has had a troubled existence from its birth. Hoping to relieve the enormous traffic over the Brooklyn Bridge, Gustov Lindenthal, Commissioner of the New York City Department of Bridges, proposed a steel wire suspension bridge over the East River in 1901. When this design was rejected for aesthetic reasons, Lindenthal came back with much debated plans for another version that featured four main cables made from chains of eye-bars, not steel wire. (Eye bars are flat 10-foot lengths of nickel-steel joined at their ends by steel pins. The arrangement is similar to a bicycle chain.) The cables were to be held aloft by two thin-profile steel towers.
A new mayor who came into office in 1904 appointed a new bridge commissioner, who, in turn, opted for another design, this one by Leon Moiseeiff. The new plan, also a suspension bridge, retained Lindenthal’s thin-profile towers, but rejected the eye-bar chain in favor of steel wire. Most crucial, Moisieff’s overall design relied on an experimental new bridge engineering principle called deflection theory. This theory held that the inherent structure of suspension bridges makes them stronger than was originally supposed; consequently, they did not require massive stiffening trusses like those used, for example, on the Williamsburg Bridge. Deflection theory would not be fully perfected for decades, and as a result, the Manhattan Bridge was, essentially, underbuilt.
Compounding the problem, Moisseiff placed the subway and streetcar lines -- the streetcar tracks were replaced with auto lanes in the 1940s -- on the outer edges of the roadway. The heavy moving loads of the trains put a twisting strain on the lightly reinforced deck, resulting in unending maintenance headaches. To correct the problems for good, a long-term reconstruction of the Manhattan Bridge was begun in the 1980s that has only recently ended, in 2007.
The Manhattan Bridge originally featured two of the most impressive entranceways of any New York City bridge. A stone archway styled after the Porte St. Denis in Paris and designed by of Carrere and Hastings (the architectural firm that designed the New York Public Library building) still serves as the Manhattan-side portal. The somewhat less grand Brooklyn approach, which included two statues by Daniel Chester French – allegorical figures of Brooklyn and Manhattan – was dismantled in the 1960s to facilitate traffic movement. The statues were moved to the Brooklyn Museum.