The King Street Bridge, also known as the Kings Bridge, is a plate girder bridge that carries King Street over the Yarra River in the city centre of Melbourne, Victoria, Australia. The bridge continues south as an elevated viaduct, with the Crown Casino built around it in later years. The bridge is welded, steel girder with concrete deck and cantilever-suspended span construction, with suspended spans up to approximately 30 metres (100 ft) long. When it opened in 1961, the bridge had eight lanes across the Yarra River, two through lanes in each direction connecting King Street to Kings Way, in addition to two lanes on each side that connected to King Street to Yarra Bank Road. At the south end north facing on and off ramps connected to Whiteman Street, and the running lanes from the viaduct descend to ground level, with tram route 58 emerging from City Road to the median strip. In the 1990s, the development of Crown Casino closed Yarra Bank Road, and the bridge ramps were connected to the basement carpark of the casino complex. The south end of the bridge has been undergoing differential settlement between the approach ramps resting on fill, and the suspended section supported by bored piles.
History
The Country Roads Board, under instructions from the government, prepared specifications in 1956 for a bridge to cross the Yarra River. Expectations were of world-wide tenders for the design and construction of a bridge 410 feet (120 m) long and 149 feet (45 m) wide and having a continued elevated structure 1,880 feet (570 m) long and 63 feet (19 m) wide over the Yarra River at King Street, together with a viaduct crossing above the Port Melbourne and St Kilda railway lines, Whiteman Street, Queensbridge Street, City Road and Hanna Street, and returning to the present level of Hanna Street (later Kings Way) near Grant Street, South Melbourne. Together with the construction of the Flinders Street overpass, the whole project was estimated to cost A£3.5&nbps;million. Seven organisations submitted a total of 14 tenders for the work when tenders closed on 29 January 1957, and after examination by the Board's officers, the government accepted the tender of Utah Australia. Contractors from Utah Australia began their operations on the site on 25 November 1957, building a temporary bridge to give access to the eventual location of the bridge's piers over the river. The passing of the King-street Bridge Act 1957 through the Parliament of Victoria on 18 December 1957, granted formal permission for the bridge to be built, gave the Country Roads Board powers to take ownership of relevant lands and not to inhibit the operations of the Port Melbourne and St Kilda railway lines during construction, declared the road a "public highway" once completed, and apportioned the total cost of to be borne as follows: 65% by the Victorian government, 30% by the City of Melbourne, and 5% by the City of South Melbourne. The King Street Bridge was designed in 1959 by Hardcastle & Richards, consulting engineers for Utah Australia, on behalf of the Country Roads Board, and constructed over the next two years. The substructure of the main bridge was completed in November 1959, and the east and west lanes of the low-level bridge over the Yarra were completed except for hand-railing and lighting. Traffic commenced using the east and west lanes of the low-level bridge in November 1960, and on 12 April 1961, the main bridge was opened by the Premier of Victoria Henry Bolte.
Collapse Soon after completion, on 10 July 1962, one span collapsed under the weight of a 43-tonne (47-short-ton) semi-trailer, though the weight was within the bridge limits. The following, except for the "Reconstruction" section, is taken from the report of the Royal Commission.
Short history September 1956. Design and construct tenders called by the Country Roads Board of Victoria (CRB) as the Constructing Authority. May 1957. Tenders awarded. September 1957. Work started. April 1961. Open to traffic. October 1961. Bridge handed over to Melbourne and Metropolitan Board of Works (MMBW) as a metropolitan highway. July 1962. Bridge collapsed. September 1962 to August 1963. Royal Commission into the Failure of Kings Bridge.
Participants for construction CRB (Country Roads Board) – Constructing authority and contract principal UTAH Aust Ltd – Principal contractor J&W Johns & Waygood – Subcontractor to Utah for fabrication, erection and painting of girders H&R Hardcastle & Richards, consulting engineers, subcontractor to Utah for detailed design of superstructure BHP Broken Hill Propriety Ltd. for supply of steel
Design The superstructure design by H&R incorporated standard design details for girders and cover plates as was common at the time for mild steel construction. CRB had allowed in the tender the use of high tensile steel to British Standard BS 968:1941. H&R chose to use this steel to reduce weight, so economising on the cost of the foundations. Design and construction of the foundations was undertaken by UTAH. Included in the CRB tender documents were comprehensive specifications for fabrication in high tensile steel to be read in conjunction with and additional to those of BS 968 -1941. (It was suggested that the Standard may have had erroneous guidelines that were not supported by experience, and that were relied upon for this design). Neither UTAH nor J&W ever really appreciated the differences that high tensile steel presented in its fabrication, particularly with regards to welding. Therein started the road to failure.
… excerpt ends here. Continue reading the full article.
