How do you build the harbor bridge?

The Sydney Harbour Bridge is a steel through arch bridge across Sydney Harbour in Sydney, New South Wales, Australia. It is part of the city's railway, vehicular and pedestrian transport system and is the tallest steel arch bridge in the world.

The bridge was designed by John Bradfield and built by Dorman Long and Co. Ltd of England and its Australian subsidiary, the Australian Bridge Company. Construction began on 28 July 1923 and the bridge was completed eight years later on 19 March 1932.

The bridge is 1,149 metres (3,770 ft) long and its arch spans 503 metres (1,650 ft). The deck is 48.8 metres (160 ft) wide and carries eight lanes of traffic, two railway lines and a pedestrian walkway.

The bridge is a major tourist attraction and is one of the most recognisable landmarks in Sydney.