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Brooklyn Bridge- World’s 1st steel wire Suspension Bridge

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Brooklyn Bridge is the first steel-wire cable-stayed/suspension hybrid bridge in the world which is completed in 1883. It is situated in New York City that connects Manhattan and Brooklyn.

With that this is the longest suspension in the world at the time of its construction with the main span of 486.3 m. It is situated on the East River that’s why it is also known as East River Bridge.

So, let’s find out more information about this amazing structure in this blog.

In this blog, You will find out –

  1. General Introduction of Brooklyn Bridge
  2. Basic concept of structure
  3. Structural specification
  4. Services of Brooklyn Bridge
  5. Issues facing while construction of the bridge
  6. Awards & Records
  7. Visiting Brooklyn Bridge
  8. Conclusion
  9. FAQ

General Introduction of Brooklyn Bridge

Brooklyn Bridge is the brilliant feature of 19th century engineering, which uses hybrid cable-stayed/suspension bridge design. Furthermore, It’s tower is made of stones and the first time explosive was used inside a pneumatic caisson during it’s construction.

At present, New York Department of Transportation and U.S is responsible for its maintenance. National Park Service designated it as a National Historic Landmark.

John Augustus Roebling is the designer of this bridge, who was died during the construction of this bridge. The total length of the bridge is 1833.7 m with the main span of 486.3 m. It is a bridge with a width of 25.9 m and a height of 82.9 m.

The construction of Brooklyn Bridge completed in 14 years (1869-1883) and open for public on May 24, 1883.

Basic Concept of the Structure

The concept of the bridge at the East River was rising in the 1800s when a large bridge was a dream for any city. Although, the benefits of the bridge between Manhattan and Brooklyn was clear to everyone. But the width of East River is so high therefore, It seems to be impossible.

In addition, there was one more problem was that The East River was the busiest waterways on the earth. Hundreds of ships of different sizes passage through this river. So, the height of the bridge was also a big challenge for the construction of the bridge.

At that time, many engineers presented various designs, one of them was chain Link Bridge which was not possible due to the difficulties of construction. Also, There was a proposal of the tunnel under the East River. But, that was canceled due to the expensive construction.

Later, In 1852 John Roebling present a new concept, that was the use of steel in the construction of a bridge. However, in past only iron was use in the bridge construction but according to the John Roebling use of steel makes the bridge more strong.

Finally, on February 1867, the New York government passed a bill that allowed the construction of a bridge on East River between Brooklyn and Manhattan. It was the longest suspension bridge ever build in the past at that time. Originally, it was known as New York and Brooklyn Bridge or the East River Bridge but, In 1915, it was officially name as Brooklyn Bridge.

Structural Specification

Deck

In the Brooklyn Bridge long sizes, viaducts provided on both sides to provide sufficient height to the shipping. Besides that, steel was use for the construction of deck of the bridge to archive the length of 1834 meter easily. 

Suspension Span

The main span of the bridge is 486.3 meters long and 26 meters wide with a height of 38.7 meters from the water level. There are group structures of six trusses, 33 meters deep, parallel to roadways which give support to the main span and side span. Also, the trusses are capable to hold the load of 18,700 short tons.

Between the two roadways there are elevated pedestrian and cycle promenade. It is 5.5 meters above the roadways and 1.2 meters below the level of the crossbeam.

Approaches

The main span has an approach to span both sides of the bridge. Brooklyn Side Bridge has an approach ramp of 296 meters and the Manhattan side has an approach ramp of 478 meters. Renaissance-style arches give support to the approaches.

Cables

Four main cables gives support to the whole bridge. Two of them located outside of the bridge and the other two are in the middle of the roadways. The diameter of each cable is 40 cm and it contains 5,282 numbers of steel galvanized wire.

It also has a cable of 1,520 number of steel galvanized wire, under the main cable and other 400 cables extended diagonally from the tower. These all groups of cables hold the structure around the bridge deck.

Anchorages

Anchorages are provided for the main cables on both sides. These having the trapezoidal-shaped structure that transfers the tension force of the structure to the ground. In this bridge, anchorages measuring 39 x 36 m at the base and 36 x 32 m at the top with the weight of 60,000 short tonnes.  

Also, For each cable, plates are placed at the base of the anchorages. Anchorages plates size is about 16 x 17.5 inches with a width of 2.5 inches and the weight of each pate is about 21000 kg.

Towers

The bridge is lying on two towers of 85 meters tall with a base of 43 x 18 meters. Therefore, the main load of bridge is transferred through these two towers and masonry of limestone, granite, and cement were used for the construction of bridge.

However, The Manhattan tower was completed with the 35,892 cubic meters of masonry and Brooklyn tower with the 29,217 cubic meters of masonry. Also, the towers have arches for the roadways and the arch’s height is 36 meter and the width is 10.29 meters.

Caissons

Caissons are made of southern yellow pine on which both towers rest underwater. Because The Manhattan side’s tower is larger than the Brooklyn tower.

SO, the Manhattan side’s caissons size is 52 x 31 meters and located 23.9 meters below the water but the Brooklyn side’s caissons size is 51 x 31 meters and located 13.6 meters below the water.

Services of Brooklyn Bridge

The Brooklyn Bridge used as a transporting medium in multiple ways.

Vehicles Traffic

Brooklyn Bridge has four-lane roadways in two ways  and the width of the lane is just only 2.4 meters wide which is not enough for the motor vehicles. So, in 1922, motor vehicles banned on the bridge and only horse-drawn vehicles allows on it.

Rail & Cable Car Traffic

On September 25, 1883 a cable car service was started by The New York and Brooklyn Bridge Railway and Initially, only one cable car was used for transportation but after the huge demand two cable cars were started.

After that, elevated trains were also started with the cable cars. Elevated trains and cable cars operated on the bridge stopped in 1944.

Trolleys

Trolleys services were also operated on the bridge until 1950.

Walkway

The Brooklyn Bridge has a walkway for pedestrians and cycling in the center and that is 5.5 meter elevated above to the main road.

Issue Facing while Construction of the Bridge

Busy Traffic in East River

The main problem in front of engineers was the large width of The East River and also the busiest waterways on the earth. Hundreds of ships of different sizes passage through this river. So, the height of the bridge was a big challenge for the construction of the bridge.

Death of Engineer

The main chief engineer of the bridge John Augustus Roebling died at the starting work of the bridge. This makes difficulties for all and after Roebling death his son Washington Roebling taken the responsibility of chief engineer.

Awards and Records

  • It is the longest suspension in the world at the time of its construction with the main span of 486.3 m.
  • The first time explosive was used inside a pneumatic caisson during its construction.
  • First-time steel was used in the construction of the bridge. Earlier only iron was used in the bridge construction but as per the John Roebling use of steel makes the bridge more strong.

Visiting Brooklyn Bridge

After getting so much information about this amazing structure, everyone wants to get a tour of this. So, if you plan a trip to New York your trip will not complete without visiting this Bridge.

Way to reach at The Brooklyn Bridge

There are two ways to reach at The Brooklyn Bridge first from the Manhattan side and second from the Brooklyn side.

From Manhattan side

  • The first way to reach there, by personal vehicle or taxi from anywhere in the city.
  • The second way to reach there, by trains. For that you should 4,5,6 trains to Brooklyn Bridge/ city hall.

From Brooklyn side

  • The first way to reach there, by personal vehicle or taxi from anywhere in the city.
  • The second way to reach there, by Sunway. For that you can take one of these three routes
    • A, C, F to Jay Street/ MetroTech station
    • N, R to Court street station
    • 2/3 or 4/5 to Borough Hall station              

Best time to reach there

The Brooklyn Bridge is open for 24 hours and you can visit at any time. It is beautiful at any time of the day. You can go there as per your choice and whether you like the most.

Pricing

The Bridge is free for visiting.

Conclusion

In the conclusion we can say that this bridge is one of the marvels structure in history of civil engineering. The use of steel and explosive happened, first time in the bridge construction therefore, It was the kind of invention in construction industry.

Also read- Golden Gate Bridge- Most Photographed Bridge in the World

                    Panama Canal- Most Used Shortcut of the World’s Traders

Frequently Asked Questions

1. Where the Brooklyn Bridge situated ?

Brooklyn Bridge situated in New York at East river.

2. When the Brooklyn Bridge constructed ?

Brooklyn Bridge is completed in 1883.

3. For which purpose Brooklyn Bridge was used?

In past Brooklyn Bridge was used for vehicles, cable cars, cable trains, trolleys, and walkways. But at present, it is only used for small vehicles, walkways, and cycling.

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