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|This article is incomplete. (February 2011)|
Bridge construction in New South Wales starts with the needs of the first settlers and continues through to the present day with advanced bridge design. The infant colony had limited expertise and limited materials, as time passed techniques and materials were developed that allowed greater spans to be crossed and therefore expansion of the colony into otherwise inaccessible areas.
The NSW Public Works Department was under pressure from a cash strapped government to produce as much road and bridge work for as little cost as possible. The cheapest bridge was the timber truss which could be built with local timber.
All bridges are unique, in the end the bridge that is built depends on the technology, expertise, materials and need to gain access to an area.
At the time of early settlement (1788 onwards) NSW was very isolated from the technological advances being developed in Europe and North America. Materials such as cast iron were unavailable to early colonial NSW bridge builders. NSW bridge builders had to rely on their own resourcefulness, bred of isolation, distance and the unique environment.
Australia's unusual environment results in unusual, and extreme river flows, almost no flow for some parts of the year and in extreme floods in other seasons. Early settlers sometimes built rudimentary structures in low rainfall seasons only to see the structures washed away in high rainfall times. With little funds available to the authorities the trend was to build light structures that could not stand the test of high and fast flowing water.
In solving these problems, colonial NSW embraced the innovations produced by others and adapted them successfully to the unique situations presented. There are examples of some very fine 19th-century bridge engineering provided for the railway expansion, conceived mainly by British engineers working in the then isolation of the Australian inland, and we have well-developed examples of many of the newer European techniques such as cable-stayed bridges.
Australia developed around coastal communities with rudimentary road systems to inland settlements. The early years saw early bridge technology limited very much to the 18th century European technology of masonry arches and cast iron, the latter still in its infancy and not produced to any great extent in New South Wales.
NSW at the time of early settlement had an abundance of convict labour and had a need for rapid construction. In a country heavily timbered this led to basic timber structure bridges but as the Colony gained stability the government looked towards more permanent structures and, as the skills for quarrying and stone dressing became available, masonry bridges began to be designed and built. As all metal materials had to be imported, iron bridges were rarely appropriate and were in any case still too novel for colonial application. Iron bridges were only used for major crossings on important corridors.
Timber truss bridges, and timber bridges generally were so common that NSW was known to travellers as the "timber bridge state".
The following list illustrates the development of New South Wales bridge construction techniques. The list commences from the earlier constructions through to the later developments.
Sorted by date
|Built||Name||Location||Image||Construction type||Length||Use||In use||Comments||Ref||Coords|
|1833||Lennox Bridge||Glenbrook||stone arch||6m||Road||Yes||see article|
|1836||Lansdowne Bridge||Lansvale||stone arch||Road||Yes||largest span stone arch bridge in Australia|||
|1839||Lennox Bridge||Parramatta||stone arch||Road||Yes||see article|
|1858||Pyrmont Bridge||Darling Harbour||wooden pile with iron centre swing span||Road||Yes||now pedestrian and monorail||see article|
|1863||Picton Viaduct||Picton||stone arch||Rail||Yes||spans Stonequarry Creek|
|1863||Menangle Railway Bridge||Menangle||Rail||Yes||see article|
|1867||Victoria Bridge||Penrith||wrought iron girder||Road||Yes||also known as Nepean River Bridge||see article|
|1867||Knapsack Viaduct||Lapstone||stone arch||Rail|
|Yes||Now pedestrian only||see article|
|1867||Prince Alfred Bridge||Gundagai||under-slung wrought iron Warren continuous truss & timber approaches||921m||Road||No||possibly oldest iron truss in NSW|||
|1870||Denison Bridge||Bathurst||steel American Pratt truss||Road||Yes||Now pedestrian only||see article|
|1881||Nowra Bridge||Nowra||Steel Whipple Truss||342m||Road||Yes||see article|
|1881||Gladesville Bridge (the 1881 bridge)||Drummoyne||Road||No||Demolished when the new road bridge opened in 1964||see article|
|1881||Dubbo Rail Bridge||Dubbo||wrought iron lattice girder bridge||Rail||Yes|||
|1886||John Whitton Bridge (the 1886 Rail Bridge)||Meadowbank||Truss Bridge||Rail||Yes||Now bicycles and pedestrians only. New rail bridge was built to replace the original bridge in 1980. The 2 bridges make up the John Whitton Bridge.|||
|1888||Brewarrina Bridge||Brewarrina||wrought iron lift bridge with timber beam approaches||91m||Road||Yes||Now pedestrian only|||
|1891||Murrumbidgee River Rail||Wagga Wagga||wrought iron lattice truss||Rail||No||Removed in 2007||see article|
|1895||Wilcannia Bridge||Wilcannia||steel truss bridge||Road||No||Accessible to public. Used to carry Barrier Highway and spans over Darling River.|||
|1895||Hampden Bridge||Wagga Wagga||wooden Allan Truss||100.5m||Road||Yes||Closed to public. To be demolished in 2013.||see article|
|1897||Victoria Bridge||Picton||wooden Allan Truss||80m||Road||Yes||tallest trestle in nsw||see article|
|1897||Wallaby Rocks Bridge (Turon R.)||Wallaby Rocks||Allan timber truss||106.7m||Road||Yes|||
|1898||Hampden Bridge||Kangaroo Valley||suspension with sandstone turrets||Road||Yes||see article|
|1901||Hinton Bridge||Hinton||Allan truss||178.6m||Road||Yes|||
|1901||De Burghs Bridge (the 1901 bridge)||West Pymble||Road||No||Replaced by new road bridge in 1967. Old bridge destroyed by Bushfire in January 1994||see article|
|1902||Gundagai Rail Bridge||Gundagai||timber Howe deck trusses||819m||Rail||No||over Murrumbidgee River|||
|1903||St Albans Bridge||St Albans||DeBurgh timber truss||Road||Yes|||
|1911||Scabbing Flat Bridge||Dubbo||timber 'dare type' truss||Road||Yes|||
|1914||Mungindi Bridge||Mungindi||timber 'dare type' truss||Road||Yes||To be replaced by a new bridge which is under construction|||
|1916||Rawsonville Bridge||Dubbo||timber 'dare type' truss||Road||Yes|||
|1918||Fullers Bridge||Chatswood West||Road||Yes||see article|
|1924||Mulwala Bridge||Mulwala||Steel Pratt Truss||Road||Yes||see article|
|1924||Roseville Bridge (the 1924 bridge)||Roseville Chase||Road||No||Replaced by new road bridge in 1966. Used as a pedestrian bridge until it was demolished in 1974.||see article|
|1927||Subway Lane bridge||Homebush||Rail||Yes|||
|1929||Tom Uglys Bridge (the 1929 bridge)||Blakehurst||Truss bridge||499m||Road||Yes||see article|
|1932||Sydney Harbour Bridge||Sydney||steel through arch bridge||Road||Yes||see article|
|1932||Grafton||Grafton||Bascule||Road (upper deck) and Rail (lower deck)||Yes||see article|
|1935||Ryde Bridge (the 1935 bridge)||Ryde||lift bridge||Road||Yes||see article|
|1939||Long Gully Bridge (Northbridge)||Northbridge||concrete arch||Road||Yes||Rebuilt and replaced the 1892 bridge|||
The Allan truss bridge is named after Percy Allan, a famous Australian engineer who designed this bridge type. His design consisted of vertical and diagonal arrangements comprising a combination of timber and iron elements. The timber elements were designed to be in compression and the iron elements in tension. Allen's design followed extensive testing of Australian hardwoods by Prof. Warren and his early engineering students at Sydney University. The timber used was mostly ironbark because of its high strength. Other features of Allan's truss design included design to minimize later maintenance and/or replacement of elements. For this reason the trusses were built in pairs to facilitate work on a particular element without requiring the whole bridge to be supported, as was the case with previous timber designs. Allan's design was very cost-effective.
Harvey Dare was a leading engineer in the Public Works Department, and a prominent figure in early 20th century NSW. He was a designer of bridges and he developed the Dare Truss which was similar to the Allan Truss but contained improvements which make them stronger and easier to maintain. This engineering enhancement represents a significant evolution of the design of timber truss bridges, and gives Dare trusses some technical significance. Dare Trusses were the fifth of the five stages of evolution of timber truss road bridges in NSW.
In 1998 there were 27 surviving Dare trusses in NSW of the 40 built, and 82 timber truss road bridges survive from the over 400 built.
"Bridges and Roads in New South Wales". Unique Cars and Parts.