The bridges of New York City do not only serve as transportation arteries for the enormous city, connecting all five boroughs and the state of New Jersey, they are also the symbols of the art of engineering, and the evidence of an era of technological innovation in the 20th century. They are the masterpieces of bridge construction that continue working on behalf of the city until this day.
Manhattan is an island surrounded by wide rivers with strong currents. On the East side flows the East River, on the West, the Hudson River. They converge in the South and flow into the Atlantic Ocean via narrow strait called the Narrows. To the North, the island is separated from the mainland by the rather narrow Harlem River.
New York City’s transport interchanges, including bridges, are being built as the need arises. The biggest transportation problem in the 19th century was connecting Manhattan to Brooklyn. Almost up until the mid-19th century numerous ferries, which transported Brooklyn residents to Manhattan for work and back home every day, were the primary connection. Freight traffic increased annually, but the ferries were not operational during wintertime, since the middle of the East River froze. Only a bridge across the river could solve the problem.
The Brooklyn Bridge was constructed first; therefore, it will always remain a turning point in the history of New York City. However, the history of its construction is tragic. The architect of the bridge, John Augustus Roebling, who designed a unique structure of wire rope suspensions and began erecting underwater pillars, died unexpectedly. He was injured when an arriving ferry crashed into one of the pillars. The toes on one of his feet were amputated, but he still died of blood infection. The construction work was continued by his 32-year-old son, Washington Roebling, who personally controlled the erection of the underwater pillars that would go down to the bottom of the river with workers in special boxes filled with compressed air, not yet aware yet that this would lead to caisson disease. A hundred people died as a result of this illness while erecting underwater pillars, and when the architect himself fell sick, his wife passed his daily construction orders to the workers.
The construction of the Brooklyn Bridge lasted for almost 14 years. It was completed in 1883. The bridge is 5,989 feet long and has three lanes – two for automobile traffic and one for pedestrians. It is safe to say that the bridge is New York residents’ favorite. There is a tradition in which every city resident must walk across the bridge at least once in his or her lifetime.
The Williamsburg Bridge was the second bridge to be built, also connecting Manhattan and Brooklyn. It is also a suspension bridge, but its causeways are made of hard metal truces. The construction work lasted for seven years, and the bridge was completed in 1903. It is 7,308 feet long and 118 feet wide. The bridge provides eight lanes of roadway, a subway line, and special lanes reserved for pedestrians and bicycles. Clearance below the bridge is 135 feet, which allows for the passing of river traffic.
At that point, the city finally decided to build a bridge to connect the middle of Manhattan to Queens in the neighborhood of Long Island City, construction of the Queensboro Bridge was being discussed since the early 19th century. It was decided to erect the bridge through Roosevelt Island in the middle of the East River. This was a unique opportunity to erect two cantilever arms on the island and build console structures for the main span off. The bridge has a total of five spans. The project began to be implemented only by 1902, but the construction work was delayed due to labor unrest, during which the workers even threatened to dynamite one span.
This bridge accounts for tremendous traffic load: two levels carry automobile lanes, a Subway line, two pedestrian and one bicycle lane. The bridge was completed in 1909. It is 3,724 feet long, 100 feet wide, and has a 130-feet clearance below. This bridge is sometimes called the 59th Street Bridge, since it ends at 59th street in Manhattan.
A fourth bridge over the East River, the Manhattan Bridge, was constructed at the same time. This bridge leads from Chinatown, Manhattan directly to downtown Brooklyn. Construction of this very long bridge, and its length is almost twice the length of the bridges erected before, was made possible thanks to Josef Melan’s new deflection theory. Calculating acceptable angles of the truss curves allowed not only increase the length twofold, but also to lighten the structures themselves. As a result, with a width of 120 feet, its total length is 6,855 feet, and the length of its longest span is 1,480 feet. The bridge has two levels and its clearance below is 135 feet. It was completed in 1909.
It turned out that by the beginning of the 20th century, the eastern side of Manhattan had four bridges connecting across the East River, while the western side across the Hudson River to the state of New Jersey had none. The main reason for that was that the Hudson River is almost twice the width of the East River, and no bridges of such length had been constructed anywhere in the world.
However, the moment had arrived, and the city began construction of a bridge from Upper Manhattan to the town of Fort Lee, New Jersey. Othmar H. Ammann, a brilliant bridge architect, was commissioned to erect it. Construction work began in 1927, and the bridge was to be called the Hudson River Bridge. The erected pivot pillars, each 603 feet tall, were higher than any Manhattan structure at the time. A 3609-feet-long suspended structure was stretched over them, with the length of the bridge totaling 4,757 feet. Ammann was able to erect such a structure thanks to experience he accumulated while constructing other bridges; in particular, applying the “deflection theory,” as well as utilizing metal that had never been used before.
The construction coincided with the Great Depression, and the city council asked the architect to reduce the cost estimates. After remodeling the project, Ammann dropped the stone finish of the pivot pillars and other architectural design elements. Thus, today we see the open metal bridge creating an illusion of airiness. Additionally, due to cost-reduction, Ammann abandoned his plans for the lower-level canopy, although he preserved this detail in the project.
The bridge opening ceremony took place on October 24, 1931. It became known as the George Washington Bridge, after the first American President. Although this bridge has dropped to 14th place in the ranking of the longest span in the world, it still has the highest number of traffic lanes totaling 14. This was made possible thanks to the inherent design capabilities incorporated by Ammann: two more lanes were added in 1946, and a suspended lower level was added in 1962.
Four more large bridges were built in New York City in the middle of the 20th century. All of them serve as vital transportation arteries to this day, and Othmar Ammann built all of them. The Triborough Bridge, the Bronx-Whitestone Bridge, and the Throgs Neck Bridge were all designed according to the newest research in the field of structure fluctuations, as well as the decision to forego design elements and excessive decoration. All of the new bridges have a simple look and an open design.
The Verrazano-Narrows Bridge, that finally connected Staten Island and Brooklyn, was the last one to be built. It is named after the first European seafarer to enter New York Bay via the Narrows strait, going up the Hudson River. This is a two-level suspended bridge with the longest span of 4,460 feet and two side spans of 1,214 feet each. Until 2014, the bridge was considered to have the longest suspended span in the world. Each level carries six traffic lanes, the height of the pillars is 693 feet, and the clearance below is 228 feet, allowing the largest ocean liners to enter New York Harbor.
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