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Sydney Harbour Bridge

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The Sydney Harbour Bridge is a massive steel through arch bridge in Australia.

Sydney Harbour Bridge from the air
Sydney Harbour Bridge from the air

It spans the water from the Sydney central business district to the North Shore. This structure is a vital part of the city's transport system. It carries rail, vehicular, bicycle, and pedestrian traffic across the harbour. Many people recognize the bridge as an iconic symbol of Australia.

Sydney Harbour Bridge from Circular Quay
Sydney Harbour Bridge from Circular Quay

Because of its distinct arch design, it is often nicknamed "the Coathanger."

The bridge functions through a complex steel arch mechanism. This arch is composed of two 28-panel arch trusses. The height of these trusses varies from the center to the ends. The arch has a total span of 503 meters. On very hot days, the steel structure expands. This thermal expansion can increase the height of the arch by about 18 centimeters.

The entire structure is held together by six million hand-driven rivets. These rivets were supplied by the McPherson company of Melbourne. Workers heated the rivets until they were red-hot. They then inserted them into the plates and used pneumatic guns to round them over.

There are several distinct parts and lanes on the bridge. The main roadway is called the Bradfield Highway. It contains six original lanes of road traffic. There are also two additional lanes on the eastern side. These eastern lanes formerly served as tram tracks. A dedicated pedestrian path runs along the eastern side. A separate path for bicycles runs along the western side. The North Shore railway line sits between the roadway and the bicycle path.

The history of the bridge involves many decades of planning. Proposals to cross the harbour date back to 1814. Architect Francis Greenway suggested a bridge to Governor Lachlan Macquarie. Other engineers like Robert Brindley and Peter Henderson made various proposals in the 1800s. In 1900, a worldwide competition for a design was organized. However, economic downturns prevented construction from starting early on. John Bradfield became the Chief Engineer in 1914. He is widely known as the "father of the bridge."

JJC Bradfield Sydney Harbour Bridge 1932
JJC Bradfield Sydney Harbour Bridge 1932

Construction was a massive international effort. The British firm Dorman Long of Middlesbrough won the contract in 1924. Their bid was for a price of AU£4,217,721 11s 10d. The design was inspired by the Hell Gate Bridge in New York City.

Hell Gate Bridge cricket
Hell Gate Bridge cricket

About 79% of the steel was imported pre-formed from England. The remaining steel came from the Newcastle Steelworks. Dorman Long set up two workshops at Milsons Point to fabricate parts. The bridge finally opened to the public in 1932.

Aerial view of Sydney and Circular Quay on the day of the official opening of the Sydney Harbour Bridge, 19 March, 1932 (6174053762)
Aerial view of Sydney and Circular Quay on the day of the official opening of the Sydney Harbour Bridge, 19 March, 1932 (6174053762)

The bridge features four large concrete pylons at the ends. These pylons are faced with granite from Moruya. A group of 250 stonemasons worked at the Moruya quarry. They cut and numbered the stone blocks before shipping them to Sydney. Interestingly, the pylons have no structural purpose for the arch. They were added to provide visual balance and to calm public concern. Today, these pylons serve many functional roles. One pylon houses a museum and a 360° tourist lookout.

Sydney Harbour Bridge SE Pylon, jjron, 02.12.2010
Sydney Harbour Bridge SE Pylon, jjron, 02.12.2010

Others support CCTV cameras or serve as maintenance sheds.

Numerical details highlight the bridge's immense scale. The total weight of the steelwork is approximately 52,800 tonnes. The arch itself accounts for a large portion of this weight. At the time of its completion, it was the world's widest long-span bridge. It remained the widest until the Port Mann Bridge opened in 2012. It is also the tallest steel arch bridge when measured from the top to the water level. These dimensions make it the eleventh-longest spanning-arch bridge in the world.

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🖼️ Images & Media (32)
File:Sydney Harbour Bridge from the air.JPG
Sydney Harbour Bridge from the air.JPG
File:Sydney Harbour Bridge from Circular Quay.jpg
Sydney Harbour Bridge from Circular Quay.jpg
File:SydneyHarbourBridgeNutMilsonsPoint.JPG
SydneyHarbourBridgeNutMilsonsPoint.JPG
File:Sydney Harbour Bridge SE Pylon, jjron, 02.12.2010.jpg
Sydney Harbour Bridge SE Pylon, jjron,...
File:Sydney harbour Bridge 1857 SLNSW FL6257399.jpg
Sydney harbour Bridge 1857 SLNSW FL6257399.jpg
File:Sydney Harbour Bridge designs submitted, 1900.gif
Sydney Harbour Bridge designs submitted, 1900.gif
File:Ernest Stowe Proposed Sydney Harbour Bridge.jpg
Ernest Stowe Proposed Sydney Harbour Bridge.jpg
File:Norman Selfe proposal for Sydney Harbour Bridge.jpg
Norman Selfe proposal for Sydney Harbour...
File:Hell Gate Bridge cricket.jpg
Hell Gate Bridge cricket.jpg
File:Opening_of_Tenders_(Sydney_Harbour_Bridge)_(6352488398).jpg
Opening_of_Tenders_(Sydney_Harbour_Bridge)...
File:Aerial view of Sydney Harbour - the bridge is under construction.jpg
Aerial view of Sydney Harbour - the...
File:Early construction, Sydney Harbour Bridge.jpg
Early construction, Sydney Harbour Bridge.jpg

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