Commonwealth Avenue Bridge

The current bridge is the fourth crossing over the Molonglo River. The first Commonwealth Avenue Bridge, completed 1916, was damaged in the 1922 flood. The second, using three Leychester-type trusses, was completed in 1924 and damaged in floods a year later. The third bridge, completed in 1927, was a modification of the 1924 bridge, by raising the bridge by {{convert|1|m|ft|0|spell=on}} and adding a fourth truss.{{cite web |url=http://www.images.act.gov.au/duslibrary/imagesact.nsf/V01/F0E62B305474F39CCA25726700086630?OpenDocument |author=Mildenhall, William James |title=Second Commonwealth Avenue Bridge |format=image |work=ACT Heritage Library: ImagesACT |publisher=Government of the Australian Capital Territory|date=1925 |access-date=25 March 2020}} At that time, Molonglo River was not dammed to form Lake Burley Griffin. Building on the plan developed by Walter Burley Griffin, in 1957 William Holford proposed to the federal government that the Molonglo be dammed near Yarralumla and that Canberra's 'two halves' should be joined via a lake.{{cite web |url=http://guides.naa.gov.au/records-about-act/part1/chapter5/5.1.aspx |title=The Holford Report |work=Government Records about the Australian Capital Territory |publisher=National Archives of Australia |editor=Ling, Ted |format=Part 1: Chapter 5 |date=2013 |access-date=25 March 2020 }}

Construction of the Commonwealth Avenue Bridge began in March 1961 and the bridge was opened in November 1963. Concurrently, the Kings Avenue Bridge was opened in March 1962; and Scrivener Dam was completed in September 1963. Both bridges were built over a dry riverbed as Canberra was in the grip of drought. It took some time for the lake to fill; finally filled for the first time on 29 April 1964.{{cite web |url=http://guides.naa.gov.au/records-about-act/part1/chapter5/5.3.aspx |title=Expansion on a grand scale |work=Government Records about the Australian Capital Territory |publisher=National Archives of Australia |editor=Ling, Ted |format=Part 1: Chapter 5 |date=2013 |access-date=25 March 2020 }}

Designed by Maunsell & Partners and built by Hornibrook, the Commonwealth Avenue Bridge comprises five spans of continually pre-stressed concrete, totalling {{convert|310|m}}. The provide an entry and exit clover leaf layout, on the bridges southern approaches, operate structures were constructed totalling {{convert|49|m}} each, in four approximately equal spans.{{cite web |url=https://portal.engineersaustralia.org.au/system/files/engineering-heritage-australia/nomination-title/Lake_Burley_Griffin_Nomination.pdf |title=Lake Burley Griffin Scheme, consisting of Lake impounded by Scrivener Dam, and Commonwealth and Kings Ave. bridges |publisher=The Institution of Engineers, Australia, Canberra Division |date=22 February 2001 |access-date=25 March 2020 |format=Chapter 6 |page= |isbn= |author= }} The main superstructure is of multi-web box section shape, continuous over the five spans, ranging from {{convert|185|to|240|ft|m|0|order=flip}}. The central piers, octagonal in shape, are carried on {{convert|6|ft|m|0|adj=on|order=flip}} diameter reinforced concrete cylinders. Each of the pre-cast concrete box girder sections are {{convert|10|ft|m|0|order=flip}} each.{{cite journal |author1=Birkett, E. M. |author2=Fernie, G. M. |title=Bridges in the Canberra Central Lake Area - Design |journal=The Journal of the Institute of Engineers, Australia |publisher=The Institution of Engineers, Australia |volume=36 |date=July 1964 |access-date=25 March 2020 |pages=139–147 |url=https://portal.engineersaustralia.org.au/system/files/engineering-heritage-australia/nomination-title/Lake_Burley_Griffin_Nomination.pdf }}{{cite web |author=Kelleher AO, Graeme |url=https://lakeburleygriffinguardians.org.au/commonwealth-avenue-bridge-heritage/ |title=Commonwealth Avenue Bridge - Heritage |work=Lake Burley Griffin Guardians |publisher= |date=6 July 2019 |access-date=25 March 2020 }}

In 2019 a detailed analysis for the strengthening and widening of Commonwealth Avenue Bridge was presented in a business case for the project. In late 2020 the project was evaluated and accepted by Infrastructure Australia{{Cite web |title=Commonwealth Avenue Bridge |url=https://www.infrastructureaustralia.gov.au/projects/commonwealth-avenue-bridge|website=Infrastructure Australia}} and in January 2021, the Federal Government announced funding to renew the Bridge.

That project is unrelated to the ACT Government's plan to extend Canberra light rail network from Civic to Woden{{Broken anchor|date=2025-01-20|bot=User:Cewbot/log/20201008/configuration|target_link=Light rail in Canberra#Stage 2: Civic to Woden|reason= The anchor (Stage 2: Civic to Woden) has been deleted.}}.{{cite news |author=Dingwell, Doug |url=https://www.watoday.com.au/national/act/move-to-widen-commonwealth-ave-bridge-renew-dam-gets-federal-backing-20190403-p51ag1.html |title=Move to widen Commonwealth Ave Bridge, renew dam gets federal backing |work=WAtoday|date=3 April 2019 |access-date=25 March 2020 }}{{cite news |author=Bushnell, Ian |url=https://the-riotact.com/light-rail-prompts-nca-to-look-at-replacing-commonwealth-avenue-bridge/303187 |title=Light rail prompts NCA to look at replacing Commonwealth Avenue Bridge |work=RiotACT |date=22 May 2019 |access-date=25 March 2020 }}

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{{CC-notice|cc=by3au|url=http://guides.naa.gov.au/records-about-act/|editor=Ling, Tedname=Government Records about the Australian Capital Territory|year=2013|accessdate=25 March 2020}}

{{commons category|Commonwealth Avenue Bridge, Canberra}}

• {{cite AV media |url=https://nla.gov.au/nla.obj-143758247/view |title=Commonwealth Avenue Bridge under construction - detail, Canberra |author=Clough, Richard |work= |publisher= |via=Trove, National Library of Australia |date=1963 |format=photograph }}
• {{cite AV media |url=http://guides.naa.gov.au/records-about-act/gallery/image002.aspx |title=Commonwealth Avenue Bridge, Canberra |author= |work= |publisher=National Archives of Australia |date=1963 |format=photograph }}

Category:Road bridges in the Australian Capital Territory

Category:Bridges completed in 1963

Category:1963 establishments in Australia

Category:Concrete bridges in Australia

Category:Buildings and structures in Canberra