|
The MANHATTAN BRIDGE spans the East River north of the Brooklyn Bridge. The Manhattan terminal is at the Bowery and Grand street; the Brooklyn end opens on Nassau near Bridge street. The river span is 1,470 feet, each land span is 725 feet, the Manhattan approach 2,067 feet, Brooklyn approach 1,868 feet—total length of roadway 6,855 feet. The towers are 322 feet above mean high water mark.
THE WILLIAMSBURG BRIDGE, from Williamsburg, Brooklyn, to Grand street, Manhattan, was the greatest suspension bridge in the world, with a channel span of 1,600 feet, a length of 7,200 feet between terminals, a height of 135 feet at the center, and towers 335 feet. The bridge is 118 feet wide and carries four trolley and two cable tracks, two roadways and two foot walks.
THE QUEENSBORO BRIDGE extends across the East River from East Fifty-ninth street, in the Borough of Manhattan, to Ravenswood, in the Borough of Queens, and is supported by two piers rising from Blackwell's Island. In weight and carrying capacity it is the greatest cantilever bridge in the world. The length of the bridge proper is 3,724 feet 6 inches; the entire length, including the approaches, is 8,231 feet. The Manhattan approach, built chiefly of masonry, 1,051 feet in length, extends to a pier on the river edge. Here the truss construction begins with the shore arm, 470 feet in length, of the westerly cantilever. The river span west of the island consists of two cantilever arms, each 591 feet in length, making a total westerly river span of 1,182 feet, dimensions exceeded only by the other New York structures, the Brooklyn Bridge with a span of 1,195 feet, the Williamsburg Bridge, 1,600 feet, and Scotland's great bridge across the Frith of Forth, 1,710 feet. The span between the two piers on Blackwell's Island is 630 feet; the river span east of the island is 984 feet; the shore arm of the easterly cantilever is 459 feet; the Long Island approach is 3,455 feet.
The super-structure is carried on masonry towers which are 185 feet in height above the bottom chord. The clear height of the bridge above mean high water is 135 feet. The carrying capacity is enormous. There are two floors, the lower one 86 feet wide between railings, the upper one 67 feet. The lower floor carries a roadway 56 feet wide for street and vehicular traffic, and having two trolley tracks; and two other trolley tracks are carried on extensions of the floor beams. On the upper floor is provision for four elevated tracks and two 13-foot sidewalks. The sustaining strength of the bridge has been calculated for the upbearing of 250 rapid transit cars carrying 30,000 passengers, 300 trolley cars with 30,000 passengers, a congested traffic on the promenades of 55,000 persons, and on the roadway of I00,000—a total of 215,000. The bridge was de-signed by Gustav Lindenthal.
Go To Next Page
|
