George Washington Bridge Construction
The George Washington Bridge stands high above the Hudson River, its eastern end resting on the shores of Manhattan, its western end embedded in the wooded bluffs of New Jersey's Palisades. Twice as long as any previous suspension bridge, it was the marvel of its time and, to some, it will always be the noblest of all bridges. Spanning the river to link New York City and New Jersey had challenged planners and engineers for over 100 years before Othmar Ammann, the brilliant, Swiss-born architect and engineer, proposed a bridge design in 1923 that ultimately was chosen above all others. The Port Authority, with Ammann as its new chief engineer, began construction in October of 1927. Ammann's design, bold and foresighted, was an engineering tour de force, with an extraordinary 3, 500-foot center span suspended between two 570-foot steel towers, and the strength to carry two levels of roadway or rail.
The physical construction of the bridge is itself a marvel of engineering. The four main cables are each composed of a single strand carried back and forth across the river 61 times. Each strand-itself a bundle of 434 individual wires-wraps around a strand shoe in the anchorage before looping back toward the opposite shore. Each shoe connects to a bar sunk deep into the anchorage that holds the strand in place.
The two towers were built first. Once the towers were in place, the four main cables, each a yard in diameter, were strung from shore to shore up over the top of each tower. Next, steel suspenders were hung from the main cables, to support the roadway. Finally, the bridgemen built the road itself, foot by foot, out from the shores, hanging it from the steel suspenders as they went.
The New York anchorage, into which the main cables are anchored, consists of 110, 000 cubic yards of concrete weighing 260, 000 tons. On the New Jersey side, the main cables are tied directly into the rock of the Palisades fronting the Hudson River. At the time, this required the excavation of 200, 000 cubic yards of solid rock.
The George Washington Bridge was first opened to traffic in 1931. During the first full year of operation in 1932 more than 5.5 million vehicles used the original six-lane roadway. As traffic demand increased, additional construction became necessary. The two center lanes of the bridge, which had been left unpaved in the original construction, were opened to traffic in 1946, increasing capacity of the bridge by one-third. The six lanes of the lower roadway were completed in 1962.