when did construction start on the sydney harbour bridge
on 28 July 1923
title: Sydney Harbour Bridge text: both private homes and commercial operations, were demolished to allow construction to proceed, with little or no compensation being paid. Work on the bridge itself commenced with the construction of approaches and approach spans, and by September 1926 concrete piers to support the approach spans were in place on each side of the harbour. As construction of the approaches took place, work was also started on preparing the foundations required to support the enormous weight of the arch and loadings. Concrete and granite faced abutment towers were constructed, with the angled foundations built into their sides. Once work had progressed title: Sydney Harbour Bridge text: 28, specifying the construction of a high-level cantilever or arch bridge across the harbour between Dawes Point and Milsons Point, along with construction of necessary approaches and electric railway lines, and worldwide tenders were invited for the project. As a result of the tendering process, the government received twenty proposals from six companies; on 24 March 1924 the contract was awarded to British firm Dorman Long and Co Ltd, of Middlesbrough well known as the contractors who built the similar Tyne Bridge of Newcastle Upon Tyne, for an arch bridge at a quoted price of AU£4,217,721 11s 10d. The arch title: Sydney Harbour Bridge text: were also all added to the bridge in 1931. The pylons were built atop the abutment towers, with construction advancing rapidly from July 1931. Carpenters built wooden scaffolding, with concreters and masons then setting the masonry and pouring the concrete behind it. Gangers built the steelwork in the towers, while day labourers manually cleaned the granite with wire brushes. The last stone of the north-west pylon was set in place on 15 January 1932, and the timber towers used to support the cranes were removed. On 19 January 1932, the first test train, a steam locomotive, safely crossed the bridge. title: Sydney Harbour Bridge text: design was cheaper than alternative cantilever and suspension bridge proposals, and also provided greater rigidity making it better suited for the heavy loads expected. Bradfield and his staff were ultimately to oversee the entire bridge design and building process, while Dorman Long and Co's Consulting Engineer, Sir Ralph Freeman of Sir Douglas Fox and Partners, and his associate Mr. G.C. Imbault, carried out the detailed design and erection process of the bridge. Architects for the contractors were from the British firm John Burnet & Partners of Glasgow, Scotland. The building of the bridge coincided with the construction of a system title: Sydney Harbour Bridge text: and opened in 1932. The bridge's design was influenced by the Hell Gate Bridge in New York City. It is the sixth longest spanning-arch bridge in the world and the tallest steel arch bridge, measuring from top to water level. It was also the world's widest long-span bridge, at wide, until construction of the new Port Mann Bridge in Vancouver was completed in 2012. The Sydney Harbour Bridge was added to the Australian National Heritage List on 19 March 2007 and to the New South Wales State Heritage Register on 25 June 1999. The southern end of the bridge is