George Washington Bridge
The George Washington Bridge is a double-decked suspension bridge spanning the Hudson River, connecting Fort Lee in Bergen County, New Jersey, with the Washington Heights neighborhood of Manhattan, New York City. It is named after George Washington, a Founding Father of the United States and the country's first president. The George Washington Bridge is the world's busiest motor vehicle bridge, carrying a traffic volume of over 104million vehicles, and is the world's only suspension bridge with 14 vehicular lanes. The George Washington Bridge measures long, and its main span is long. It was the longest main bridge span in the world from its 1931 opening until the Golden Gate Bridge in San Francisco opened in 1937.
The bridge is informally known as the GW Bridge, the GWB, the GW, or the George, and was known as the Fort Lee Bridge or Hudson River Bridge during construction. It is owned by the Port Authority of New York and New Jersey, a bi-state government agency that operates infrastructure in the Port of New York and New Jersey. The George Washington Bridge is an important travel corridor within the New York metropolitan area. It has an upper level that carries four lanes in each direction and a lower level with three lanes in each direction, for a total of 14 lanes of travel. The speed limit on the bridge is. The bridge's upper level also carries pedestrian and bicycle traffic. Interstate 95 and U.S. Route 1/9 cross the river via the bridge. U.S. Route 46, which lies entirely within New Jersey, terminates halfway across the bridge at the state border with New York. At its eastern terminus in New York City, the bridge continues onto the Trans-Manhattan Expressway.
The idea of a bridge across the Hudson River was first proposed in 1906, but it was not until 1925 that the state legislatures of New York and New Jersey voted to allow for the planning and construction of such a bridge. Construction on the George Washington Bridge started in September 1927; the bridge was ceremonially dedicated on October 24, 1931, and opened to traffic the next day. The opening of the George Washington Bridge contributed to the development of Bergen County, New Jersey, in which Fort Lee is located. The upper deck was widened from six to eight lanes in 1946. The six-lane lower deck was constructed beneath the existing span from 1959 to 1962 because of increasing traffic.
Design
The George Washington Bridge was designed by chief civil engineer Othmar Ammann, design engineer Allston Dana, and assistant chief engineer Edward W. Stearns, with Cass Gilbert as consulting architect. It connects Fort Lee in Bergen County, New Jersey, with Washington Heights in Manhattan, New York. The bridge's construction required of fabricated steel; of wire, stretching ; and of masonry.Decks
The bridge carries 14 lanes of traffic, seven in each direction. As such, the George Washington Bridge contains more vehicular lanes than any other suspension bridge and is the world's busiest vehicular bridge. The fourteen lanes of the bridge are split unevenly across two levels: the upper level contains eight lanes while the lower level contains six lanes. The upper level opened on October 25, 1931, and is wide. The upper level originally had six lanes, though two more lanes were added in 1946. Although the lower level was part of the original plans for the bridge, it did not open until August 29, 1962. The upper level has a vertical clearance of, and all trucks and other oversize vehicles must use the upper level. Trucks are banned from the lower level, which has a clearance of. All lanes on both levels are wide. Vehicles carrying hazardous materials are prohibited on the lower level due to its enclosed nature. HAZMAT-carrying vehicles may use the upper level, provided that they conform to strict guidelines as outlined in the Port Authority's "Red Book".File:Crossing the Hudson River on the George Washington Bridge from Fort Lee, New Jersey to Manhattan, New York.jpg|thumb|Manhattan-bound traffic on the upper deck of the bridge|leftThere are two sidewalks on the upper span of the bridge, one on each side. The northern sidewalk was largely closed after the September 11 attacks; it reopened in 2017 while a temporary suicide prevention fence was installed on the southern sidewalk, in preparation for the installation of permanent fences on both sidewalks. Prior to 2023, pedestrians had to traverse a total of 171 steps while using the northern sidewalk. As part of a renovation, the steps were replaced by a ramp, and two viewing platforms were added., the northern sidewalk is closed at night.The George Washington Bridge has a total length of, while its main span is long. Accounting for the height of the lower deck, the bridge stretches above mean high water at its center, and above mean high water under the New York anchorage. The bridge's main span was the longest main bridge span in the world at the time of its opening in 1931, and was nearly double the of the previous recordholder, the Ambassador Bridge in Detroit. It held this title until the opening of the Golden Gate Bridge in 1937. Prior to the bridge's construction, engineers had believed that a suspension span's length was a large indicator of a suspension bridge's economic feasibility, but the bridge's completion proved that longer suspension bridges were both physically and economically feasible.
The George Washington Bridge's total width is. When the upper deck was built, it was only thick without any stiffening trusses on the sides, resulting in a deck weighing and a length-to-thickness ratio of about 350 to 1. At the time of the George Washington Bridge's opening, most long suspension spans had stiffening trusses on their sides, and spans generally had a length-to-thickness ratio of 60 to 1, which translated to a weight of and a thickness equivalent to an 11-story building. During the planning process, Ammann designed the deck around the "deflection theory", an as-yet-unconfirmed assumption that a longer suspension deck did not need to be as stiff in proportion to its length, because the weight of the longer deck itself would provide a counterweight against the deck's movement. This had been tested by Leon Moisseiff when he designed the Manhattan Bridge in 1909, though it was less than half the length of the George Washington Bridge. Stiffening trusses were ultimately excluded from the George Washington Bridge's design to save money; instead, a system of plate girders was installed under the upper deck. This provided the stiffening that was necessary for the bridge deck, and it was replicated on the lower deck during its construction. The plate-girders underneath each deck, combined with an open-truss design on the bridge's side that connected the decks with each other, resulted in an even stiffer span that was able to resist torsional forces.
Cables
Four -diameter main cables support the bridge deck. Each main cable contained 61 strands of wire rope, with each strand made of 434 individual wires, for a total of 26,474 wires per main cable, and 105,986 in all. The cables are covered by a sheath of weather-resistant steel. The upper bridge deck is held by vertical suspender cables attached directly to the main cables by saddle connections; the lower deck is supported by girders attached to the upper. There are 592 suspender cables, which are long.The main cables are anchored in concrete on both sides of the bridge, in a purpose-built anchorage on the New York side and bored and set directly into the cliffs of the Palisades on the New Jersey side. Originally, the end of each cable was supposed to receive one of several ornamental designs, such as a wing, fin, tire, or statue; cost-savings after the start of the Great Depression in 1929 preempted the flourishes.
Suspension towers
The suspension towers on each side of the river are each tall. They are composed of sections weighing between and contain a combined 475,000 rivets. Each bridge has two archways, one above and one below the decks. The George Washington Bridge is classified as a fracture critical bridge, making it vulnerable to collapse if parts of the towers were to fail, although the towers are located offshore.The original design called for the towers to be encased in concrete and granite in a Revival style, similar to the Brooklyn Bridge. Additional scrutiny of the proposed bridge's engineering found that the steel alone could support the towers, with only a decorative stone facade being retained in the plan. Elevators to carry sightseers to restaurants and observatory proposed decks at the top of each tower were also all pared from the design. Ultimately, even stone facades were postponed in 1929 during the Great Depression due to rising material costs. Even though the steel towers had been left that way for cost reasons, some aesthetic critiques of the bare steel towers were favorable. Several groups, such as the American Institute of Steel Construction, believed that covering the steel framework with masonry would be both misleading and "fundamentally ugly".
While the exposed steel towers' design was negatively received by a few critics such as Raymond Hood and William A. Boring, the public reception at the bridge's opening was generally positive. The Swiss-French architect Le Corbusier wrote of the towers: "The structure is so pure, so resolute, so regular that here, finally, steel architecture seems to laugh." Milton MacKaye wrote in The New Yorker that the George Washington Bridge had established Ammann as "one of the immortals of bridge engineering and design, a genius." Ammann never incorporated masonry towers in his bridge plans again. He wrote that the "sturdy appearance and well-balanced distribution of steel in the columns and bracing" gave the bridge's towers "a good appearance, a neat appearance". Over time, the exposed steel towers, with their distinctive criss-crossed bracing, became one of the George Washington Bridge's most identifiable characteristics.