NYC - LES: Manhattan Bridge
The Manhattan Bridge is a 6,885 foot suspension bridge, with a span of 1,470 feet, crossing the East River and connecting The Bowery in Chinatown with Flatbush Avenue in Brooklyn.
"Suspension Bridge Number 3", as it was first called, was first conceived of as a traditional wire cable suspension bridge to be used exclusively by trains in tandem with the mixed traffic Williamsburg Bridge. In 1901 Gusav Lindenthal presented plans for a mixed traffic design, which was rejected, that called for a hybrid design, with massive steel towers and depp stiffening trusses like the Williamsburg Bridge, and vertical suspender ropes and diagonal stays like the Brooklyn Bridge. Lindenthal countered with the revised design employing a wire-cable suspension design that instead of being woven from steel wires would consist of four chains of nicel-steel eyebars; and a two-dimensional flexible tower profile, which would be the first for a suspension bridge. Concerns about inspection led to another rejection and a new bridge commissioner, Othniel Foster Nichols.
Nichols selected a new design based by Leon Moiseff based on deflection theory, which stated that three opposing forces act on the deck and cables. Chief engineer Rudolph Madjeski collaboarated with Moiseff on the new design, which incorprated Lindenthal's two-dimensional towers. However, the 322-foot-tall towers support four main wire-spun cables, each measuring 3,224 feet long, in a more traditional suspension design. The 21¼" diameter main cables were the largest suspension cables employed at the time. Together, the four cables support two decks: the lower deck originally carrying four vehicular lanes, flanked by subway tracks on each side, and the upper deck originally carrying streetcar lines situated above the subway tracks. The upper and lower decks are carried within a 26-foot-deep stiffening truss, half the depth of the Lindenthal design.
Other Lindenthal design touches were maintained at the approaches to the bridge. Carrere and Hastings, the architect team who designed the New York Public Library, lent designed the anchorages and Manhattan approach. The two granite-encased anchorages contain arches, buttresses and other architectural embellishments. A Baroque arch modeled after Porte St. Denis, a gateway to Paris, frames the Manhattan entrance to the bridge.
The four main cables were spun over the East River in a record four months time during 1908. On December 31, 1909, in what he earlier promised to be his last act in office, Mayor George McClellan formally opened the $31 million Manhattan Bridge.
National Historic Register #83001694