A symbol of Australia’s industrial history
Pyrmont Bridge is one of the world's oldest surviving electrically operated swingspan bridges. The first bridge began operating in 1857 and the current swingspan bridge opened in 1902. The bridge provided the main transport route between the city and Sydney's growing western suburbs while the swingspan allowed tall vessels to access Darling Harbour.
Pyrmont Bridge was designed by engineer Percy Allan who was renowned for his ‘common sense' approach to engineering. Each of the 583 bridges Allan designed during his career was characterised by its economical use of materials, easy construction and maintenance. Pyrmont Bridge consists of a steel truss swingspan with timber truss approach spans. Timber was used because of the high cost of iron and steel and government insistence on using local ironbark to reduce costs.
At the time using electricity to operate the swingspan was considered advanced as almost all swing bridges were operated by winches, steam or hydraulic power. The electrification of Sydney's trams provided Allan with the power and equipment he needed. The Ultimo Power House, now the Powerhouse Museum, was nearby, and tram motors, modified with appropriate gearing, were suitable to drive the swingspan.
During the 1900s, the growth of international trade saw the introduction of large container ships and the southern end of Darling Harbour became less commercially viable as a trading port. The area gradually fell into decline, freight services were moved and the railway goods yards were closed in 1984.
When Darling Harbour was redeveloped in 1988, Pyrmont Bridge's swingspan was restored and a new addition, the Monorail, was built above it. Sydney Harbour Foreshore Authority, which manages Pyrmont Bridge, has undertaken further remediation work in the past 20 years. This has included measures to prevent the swingspan jamming during hot weather and maintenance of the sand filled concrete encasements which protect the timber pile from marine borers.
The bridge is a key piece of engineering heritage and the swingspan has opened more than 600,000 times in its lifetime. An Institution of Engineers Australia commemorative plaque is at the bridge's west end and an inscription in the stonework at the eastern end recognises Percy Allan.
The bridge is generally opened for demonstrations on weekends and public holidays (weather permitting) and at other times as required for shipping. For more information contact (02) 9240 8797.
Facts and figures
- Length: 369 metres
- The bridge cost £112,500 to build
- The bridge is made up of 14 spans
- Australian ironbark timber is used on 12 spans, while the two central spans, which swing, are constructed from steel
- The swingspan weighs 1,000 tonnes and is supported on a base made from concrete and local sandstone. The base is filled with mass concrete and weighs 6,800 tonnes. It is 13 metres in diameter and 19 metres deep. The water is 6.5 metres deep and the base extends a further 10 metres below the sea floor
- Pyrmont Bridge takes approximately 60 seconds to open completely to 83 degrees. It has to be opened for vessels more than 7 metres high
- Vessels/barges up to 21.5 metres wide can pass through the channel once the Pyrmont Bridge has been opened
- Pyrmont Bridge is driven by the original two 50 Hp 600 volt DC General Electric type 57 electric motors. Manual drum-type General Electric tramway controllers are used to drive the motors for the swingspan and gates
- Power to operate the bridge was originally drawn from Ultimo Power House (now the Powerhouse Museum)
- As a young engineer, J.J.C. Bradfield (who designed the Sydney Harbour Bridge) helped design the sandstone abutment walls at each end of Pyrmont Bridge
1857 – First Pyrmont Bridge opens on 17 March
1899 – Construction starts on new bridge on 6 September
1902 – New electric swingspan Pyrmont Bridge opens on 28 June
1907 – Pyrmont Bridge is acclaimed as a marvel of modern engineering at the international conference of the Institution of Civil Engineers (London)
1981 – Pyrmont Bridge closes to all pedestrian and vehicular traffic on 7 August
1984 – Southern Darling Harbour (Cockle Bay) shipping and railway terminals close. Plans are launched to redevelop Darling Harbour into a major leisure, entertainment and commercial destination
1988 – Darling Harbour redevelopment is completed and the precinct opens to the public. Pyrmont Bridge reopens to pedestrians, connecting the city with Pyrmont and Ultimo, and the Monorail is built
2002 – Pyrmont Bridge celebrates its 100th anniversary
2013 – Monorail is removed
Today – More than 5 million pedestrians cross the bridge each year
By their very nature, timber bridge structures—particularly as they age—require an ongoing inspection and maintenance regime to maintain their loading capacity.
SHFA has a 10 year maintenance plan for Pyrmont Bridge and recently developed an open standard 3D Building Information Management system to more efficiently and cost effectively manage the bridge’s inspection, maintenance and conservation. This system replaces paper based systems and enables a more strategic and targeted maintenance methodology.
Maintenance work is planned for pier set 7 of Pyrmont Bridge. Ahead of those works, stabilisation of the pier set has closed span 7 and boating traffic is being redirected through span 8. The swing span of Pyrmont Bridge continues to operate as usual, and thousands of visitors and commuters continue to cross the bridge every day.