Five million rivets: The timeline
On 28 July 1923, ‘the turning of the first sod’ ceremony took place on the north shore where two workshops were to be erected. The first work on the Bridge was the construction of the Bridge approaches and the approach spans. By September 1926 concrete piers had been built to support the approach spans on each side of the harbour. An estimated 469 buildings – homes and businesses on the north side of the harbour – were demolished with little or no compensation, to make way for the construction of the Bridge.
During this time, work began on preparing the foundations that would carry the entire weight of the arch span and its loading. The angled foundations were built into the side of the abutment towers. The abutment towers were made of concrete, but faced with granite from a quarry at Moruya.
A giant ‘creeper crane’ was built on each side to move forward on the arches they would help construct. They were used to lift men and materials in a cradle and position them while erecting steelwork. On each shore, tunnels were excavated through which steel cables were passed to fix to the upper chords of each of the half arches to prevent their collapse as they extended out toward each other.
On 26 October 1928 the erection of the arches began. On 19 August 1930 the two halves touched for the first time. The top and bottom cords were riveted together. The arch now supported itself, and the cables could be removed. On 20 August 1930 the flags of Australia and the United Kingdom were flown from the jibs of the creeper cranes to celebrate the completion of the arch.
As each creeper crane made its way back down the arch, it hoisted hangers into position. Each pair of hangers supported crossbeams, which in turn carried the deck on which the railways and roads were to be built. The deck was in place by June 1931, and the creeper cranes were dismantled. Now the rails were laid for trains and trams. Then the deck was surfaced using concrete topped with asphalt for wheeled traffic. The two pylons at each end were now built on top of the abutment towers. The last piece of granite was added to the north-west pylon on 15 January 1932.
In February the Bridge was test loaded. All four of the rail tracks were loaded with up to 96 steam locomotives placed end to end. After three weeks of tests the Bridge was declared to be safe for traffic and was ready to be opened.