6 November 2013 - BROOKLYN BRIDGE


BROOKLYN BRIDGE

G'day folks,

Welcome to a feature on another world landmark - BROOKLYN BRIDGE. The Brooklyn Bridge is a bridge in New York City and is one of the oldest suspension bridges in the United States. Completed in 1883, it connects the boroughs of Manhattan and Brooklyn by spanning the East River.

At the time of construction, Brooklyn - founded by Dutch settlers in the 17th century - was still an independent city. In fact it was even one of the country's largest cities. In 1898, 15 years after the opening of the Brooklyn Bridge, Brooklyn citizens decided in a close vote to become a borough of New York.


Details:

Length of river span: 1595.5 feet

Total length of bridge: 5989 feet


Width of bridge floor: 85 feet


Suspension cables: four, each 15.75 inches in diameter and 3578.5 feet long, containing 5434 wires each, for a total length of 3515 miles of wire per cable


Foundation depth below high water, Brooklyn: 44 feet 6 inches


Foundation depth below high water, Manhattan: 78 feet 6 inches


Tower height above high water: 276 feet 6 inches


Roadway height above high water: 119 feet (at towers)


Total weight, not including masonry: 14,680 tons




The Brooklyn Bridge opened in 1883. At the time, it was the longest suspension bridge. It has been designated a National Historic Landmark by the National Park Service, and a New York City Landmark by the Landmarks Preservation Commission.


 Construction

 

The driving force behind the whole project, John Roebling, was a German immigrant who had worked for the Prussian government as a bridge and road builder. He launched the idea of building a bridge across the East River after he had taken a ferry across the river that ended up stuck in the ice.

John Roebling would never get to see the bridge he had designed: he died after crushing his foot in an accident. He wasn't the only one to lose his life during the construction: 20 of the in total 600 workers died while working on the bridge. The son of John Roebling, Washington Roebling, took over the leadership of the project but he suffered from the caisson-disease as a result of the works on the pillars of the bridge and was on his deathbed during the inauguration. That day, May 24, 1883, about 150,000 people crossed the bridge.

Roebling had not just made a bridge that looked incredibly strong, it also turned out to be just as strong in reality. A mesh of cables of which the four strongest have a diameter of 11 inches (28 cm) are anchored in the ground and keep the bridge from collapsing.

But even after the inauguration, many New Yorkers were not convinced the bridge was safe. So as to prove the doubters wrong, P.T. Barnum led a caravan of circus animals - including a herd of 21 elephants - across the bridge in 1884.



The Bridge

The Brooklyn Bridge ranks as one of the greatest engineering feats of the 19th century and remains one of New York's most popular and well known landmarks.

The impressive bridge spans the East river between Brooklyn and Manhattan and stretches for a length of 5989 ft, about 1.8 km. The span between the large towers measures 1595.5 ft (486 meters). This made the Brooklyn Bridge the world's largest suspension bridge.

The most noticeable feature of the Brooklyn Bridge are the two masonry towers to which the many cables are attached. The towers with large Gothic arches reach a height of 276 ft (84 meters), at the time making them some of the tallest landmarks in New York. Roebling claimed that the monumental towers would make



Footpath

An elevated pedestrian path not only gives you the opportunity to cross the river without being bothered by the traffic that rushes past a level below, but it also offers a great view of the bridge's towers as well as downtown Manhattan's skyline. The views alone attract millions of visitors to this bridge each year.







Brooklyn Bridge Commentary
 
"...it is Roebling's 1840 patent for the in-situ spinning of wire rope that has to be recognized as one of the decisive breakthroughs in modern suspension bridge technology. This patent brought John Roebling a commission to build a cable-suspended, wooden aqueduct over the Allegheny River in 1845. Roebling built a number of such aqueducts before receiving two major bridge commissions in his mid-career: his 821-foot-span Niagara rail bridge of 1841-55 and his 1,000-foot span Cincinnati Bridge of 1856-67; both of which were prototypes for the 1,600 foot Brooklyn Bridge, whose construction ran through two generations of Roeblings between 1869 and its completion in 1883. The twin masonry support towers of this vast span necessitated the building of foundations 78 feet below the water level."





Clancy's comment: Landmarks like this one always leave me gob smacked. They are still in use today and were built in times when they lacked the technology we have today. Amazing, eh?

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