|List||National Heritage List|
|Legal Status||Listed place (19/03/2007)|
|Place File No||1/12/036/0065|
|Summary Statement of Significance|
The building of the Sydney
was a major event in Australia's
history, representing a pivotal step in the development of modern Sydney and
one of Australia’s
most important cities. The bridge is
significant as a symbol of the aspirations of the nation, a focus for the
optimistic forecast of a better future following the Great Depression. With the construction of the Sydney
Harbour Bridge, Australia
was felt to have truly joined the modern age, and the bridge was significant in
fostering a sense of collective national pride in the achievement.
The Sydney Harbour Bridge was an important economic and industrial feat in Australia's history and is part of the nationally important story of the development of transport in Australia. The bridge is significant as the most costly engineering achievement in the history of modern Australia, and this was extraordinary feat given that it occurred at the severest point of the Great Depression in Australia.
The bridge is also significant for its aesthetic values. Since its opening in 1932, the Sydney Harbour Bridge has become a famous and enduring national icon, and remains Australia’s most identifiable symbol. In its harbour setting, it has been the subject for many of Australia’s foremost artists, and has inspired a rich and diverse range of images in a variety of mediums – paintings, etchings, drawings, linocuts, photographs, film, poems, posters, stained glass - from its construction phase through to the present.
The Sydney Harbour Bridge is also significant as one of the world's greatest arch bridges. Although not the longest arch span in the world, its mass and load capacity are greater than other major arch bridges, and no other bridge in Australia compares with the Sydney Harbour Bridge in its technical significance. In comparing Sydney Harbour Bridge with overseas arch bridges, Engineers Australia has drawn attention to its complexity in combining length of span with width and load carrying capacity. The construction of Sydney Harbour Bridge combined available technology with natural advantages provided by the site. The designers took advantage of the sandstone base on which Sydney was built, which enabled them to tie back the support cables during construction of the arch, and to experiment with massive structures. Although designed more than 80 years ago, the bridge has still not reached its loading capacity.
The bridge is also significant for its important association with the work of John Job Crew Bradfield, principal design engineer for the New South Wales Public Works Department, who ranks as one of Australia's greatest civil, structural and transport engineers.
includes a steel arch spanning the harbour between Milson's
Point on the north side and Dawes Point on the south side, and elevated
approaches to the arch from both the north and south sides.|
The total length of the bridge, including the approach spans, is 1149 metres. The arch is made up of two 28-panel arch trusses set in vertical planes, 30 metres apart centre to centre, and braced together laterally; it is 57 metres deep beside the pylons and 18 metres deep in the middle of the arch (Godden Mackay, 1992: ref no 0076). It is anchored by two bearings at each end, which take the weight of the bridge and allow for expansion and contraction of the steel. Under maximum load, the thrust is approximately 20,000 tonnes on each bearing (Australian Government, Culture and Recreation Portal).
The span of the arch is 503 metres and the top of the arch is 134 metres above mean sea level. The arch is founded on sandstone rock excavated to a depth of 12 metres and filled with mass concrete. A total of 39,000 tonnes of structural steel was used in the arch, over two-thirds of it silicon steel (Australian Academy of Technological Sciences and Engineering, 2000). Two granite-faced concrete pylons, with a height of 89 metres above mean sea level, are located at each end of the arch (Australian Government, Culture and Recreation Portal).
A deck carrying road and rail traffic is suspended from the arch. Pairs of hangers, ranging in length from 7.3 metres to 58.8 metres, support cross-girders, each weighing 110 tonnes. The cross-girders support the concrete bridge deck (Nicholson, 2000: 26-27). The width of the deck is almost 49 metres and the clearance for shipping is also 49 metres. The deck currently caters for eight lanes of road traffic, two railway tracks, and two pedestrian footways.
The northern and southern approaches each contain five spans, constructed as pairs of parallel-chord, six-panel steel trusses. The spans are supported by pairs of concrete piers faced with granite (Nicholson, 2000: 10-11). The combined length of the approach spans is 646 metres.
Convict architect Francis Greenway proposed a bridge over Sydney Harbour
to Governor Macquarie as early as 1815.
In January 1900, tender designs and financial proposals were sought for
a bridge to span the harbour. All of the
24 schemes were criticised and thought unsatisfactory. The 1903 design by the firm of J Stewart and
Co for a single arch bridge without pylons was rejected as being ‘too
huge’ and ‘objectionable’ from an artistic point of view (Jahn, 1997: 123).|
In 1912, the New South Wales government appointed J J C Bradfield Chief Engineer for Metropolitan Railway Construction and the Sydney Harbour Bridge (Nicholson, 2000: 5). Bradfield submitted preliminary designs for three types of bridge, cantilever, suspension and arch; he favoured cantilever, but after travelling overseas he concluded that an arch bridge would be cheaper (Carroll, 1988: 156). He completed a formal arch design for the bridge in 1916. The bridge was to carry six lanes of road traffic, railway and tram tracks and a footpath on each side. Bradfield’s design, involved more than the bridge, which was the key element of an integrated transport system including an extensive network of railways and roadways leading to the bridge, these inturn were integrated into the broader Sydney road, rail and tram system. Known as the Bradfield Scheme, the project also involved the construction of an underground railway in the Sydney CBD. The Bradfield Scheme was a visionary urban transport planning scheme including the world’s second underground railway outside of western Europe or North America and the largest single span steel bridge in the world (Lee, 2003: 43).
In 1922 the New South Wales Parliament passed the Sydney Harbour Bridge Act and designs and tenders were invited for a bridge to satisfy Bradfield’s broad requirements. The contract was let on 24 March 1924 to Dorman Long & Company of Middlesbrough, England, and included extensive approaches on either side of the arch. While Bradfield was responsible for the concept and the general design, Dorman Long and Company retained the services of English consulting engineer Sir Ralph Freeman for the detailed design of the structure. Dorman Long's tender price, including the distinctive granite pylons, was just under £4¼ million (Australian Academy of Technological Sciences and Engineering, 2000). Bradfield was responsible for overall management of the project and Lawrence Ennis was Director of Construction for the contractors (O'Connor et al, 1987: 11).
Preparatory works for the construction of the bridge approaches were undertaken by the Railways and Public Works Department, and commenced on the North Shore in late 1923, before the tender process was completed (Lalor, 2005:108). These works included the demolition of buildings, mainly houses, in the path of the bridge approaches. Owners of the properties were compensated but not housing tenants (Nicholson, 2000: 6). The concrete piers which were to support the approach spans were completed in September 1926 and the spans in September 1928 (Nicholson, 2000: 11-13).
The arch of the bridge was to be built from both ends, Milson's Point and Dawes Point, and joined in the middle. Each half-arch was built using a creeper crane with a lifting capacity of 122 tonnes, which travelled on the top chords of the arch. The half arches were secured by wire cables, anchored in inclined U-shaped tunnels cut into the rock behind the abutments at each end of the arch (Australian Academy of Technological Sciences and Engineering, 2000). Excavations for the abutments and pylons commenced in January 1925 (Nicholson, 2000: 11).
Most of the steel was manufactured in Dorman, Long's works in Middlesbrough, but the fabrication was carried out on-site in workshops specially constructed for the purpose at Milson's Point (Australian Academy of Technological Sciences and Engineering, 2000). Barges transported the fabricated steelwork from the workshops to points beneath the creeper cranes for lifting up to the arch.
By Christmas 1928, the creeper crane on the southern side was ready to hoist the first steel for the arch into place, commencing with the bearings and pins which transfer the weight of bridge to the foundations. The first panel of the arch was in place by the following March and the creeper crane edged on to the bridge (Nicholson, 2000: 15). The two half-arches were completed in August 1930, and as the steel cables taking their weight were lengthened, the bottom chords were joined on 19 August. The top chord was joined and the arch completed on 9 September 1930.
The temporary wire rope anchorages were then removed and the creeper cranes returned down the arch, erecting the hangers and deck steelwork as they went along. Deck concreting and finishing then followed (Australian Academy of Technological Sciences and Engineering, 2000). In 1931 the road and the two sets of tram and railway tracks were completed, and power and telephone lines and water, gas and drainage pipes were also installed.
The pylons, which serve a mainly aesthetic purpose, are concrete and faced with granite quarried at Moruya on the New South Wales south coast. Dorman Long recruited skilled stonemasons from Scotland and Italy to cut and shape the stone. The first block of stone was laid in October 1925 and the facing was completed by the end of 1931, after the tie-back cables had been removed from the abutments (Nicholson, 2000: 11-14, 28).
Sixteen workers died during construction, of whom seven were employed on the bridge structure itself (City of Sydney, History and Archives). Completion of the bridge in 1932 coincided with the darkest days of the Depression and many of the bridge workers released from their construction tasks swelled the growing ranks of the unemployed. The depth of the Depression in Australia stemmed from the huge debt accumulated during and after World War One. In addition to war borrowings, Australia borrowed vast amounts from Britain during the 1920s, much of it to fund urban development including ambitious works programs. By 1929 Australia owed more to the financial houses of London than all the governments of Europe, Africa, the Far East, Middle East and South America combined (Stone, 2005: 1). The actual cost of constructing the bridge was £6,250,000 which had been borrowed, adding to Australia’s debt.
New South Wales Premier Jack Lang officially opened the Sydney Harbour Bridge on 19 March 1932 amid political controversy. Australia’s perilous debt position had lead to a visit to Australia in August 1930 by Sir Otto Niemeyer, an emissary of the Bank of England to advise Australia’s political leaders as to how the debt position could be best managed. Sir Otto Niemeyer advised that the budget should be balanced using thrift and good management to resolve the debt situation. A view that was in contrast to the newly emerging Keynesian economic model that supported increased public spending to prime the economy during periods of stagflation. Government incomes were declining due to falling tax revenues and the government’s capacity to provide Depression relief would be severely restricted by further tightening its budget.
The Scullin led federal Labor Government took a conservative line and complied with Sir Otto’s advice. The impact of pursuing this line worsened the Depression and threw more workers onto the dole. In NSW a change of government in October 1930 saw a Labor Government led by Lang swept to power. Lang championed the worker’s cause promising to defy the agreement struck with Sir Otto Niemeyer and default on interest payments to British financial institutions. At the Premier’s Conference in February 1931, Lang proposed that Australia not pay any further interest to British bondholders, until Britain dealt with Australian overseas debts in the same manner as she settled her own foreign debts with America. Britain had negotiated concessions from the Americans. Lang’s actions divided the political scene including the Labor movement. Tensions rose and conservatives appealed to the Governor of New South Wales, Sir Philip Game to remove Lang.
The period also saw the emergence in New South Wales of the New Guard, a right wing militia organisation styling itself as a citizen’s army to assist the police maintain civil order in times of unrest. Funded by the 'establishment' and drawing heavily on the veterans of the First World War, the New Guard saw it’s role as defending the peace and keeping subdued any potential uprising by unionists, the unemployed and the working classes all of whom they viewed as communists. Lang with his support for the working classes and his defiance of the establishment’s subservience to the financial institutions of Britain was an anathema to the New Guard who viewed him as a danger to Australian society.
Lang’s decision, as the elected representative of the people, to preside at the opening of the Sydney Harbour Bridge was controversial in itself as it caused offence to the King who felt such a major occasion warranted royal participation or at the very least, the Governor officiating at the opening. The Governor already under pressure to remove Lang was faced with His Majesty’s displeasure. Sir Philip’s attempt to persuade the Premier to avoid offence to the monarch and permit him to officiate was unsuccessful. Premier Lang officiated at the opening, however, before he could cut the ribbon to open the bridge, Captain Francis de Groot of the New Guard slashed it with his sword. This New Guard stunt was initiated by the Guard’s leadership to thwart more radical action by some of the more extreme Guard members to kidnap Lang prior to the opening of the bridge. The opening of the bridge embodied all the political tensions of the time. This, however, did not stop large numbers of Sydneysiders and interstate visitors flocking to the opening.
The eastern pair of tramway tracks was converted to roadway in 1958 (Godden Mackay, 1992: ref no 0076). A panel which considered a proposal to add two double-lane decks over the outside lanes of the bridge, the railway and Cahill Expressway lanes, handed down its report in March 1987 (O'Connor et al, 1987). The proposal was not implemented, and the alternative of a tunnel under the harbour, which early in the twentieth century Sir John Sulman had suggested was a better option than a bridge (Jahn, 1997: 123), was adopted. The Sydney Harbour Tunnel was completed in August 1992.
|Condition and Integrity|
Changes and modifications have been made to the Sydney Harbour
Bridge over the years,
mainly to meet the demands of modern traffic. |
In 1958 the tram tracks on the eastern side were removed, replaced with two new traffic lanes and connected to the Cahill Expressway over Circular Quay. Other changes include removal of the tram viaduct at the northern approach; extensive reconstruction of the north and south approaches; the construction of the Warringah Expressway between the bridge and Miller Street, North Sydney in the 1960s; installation of toll plazas, overhead gantries and lane indicators, and many signboards; floodlighting of the bridge; and addition of an anti-suicide balustrade. There were also additions to the tops of the bridge pylons (O'Connor et al, 1987: 2-3).
After completion of the bridge, maintenance became, and still is, the responsibility of the New South Wales Government. This responsibility falls principally to the Roads and Traffic Authority of New South Wales, which may involve other bodies, such as the State Rail Authority of New South Wales, as appropriate. Conservation and maintenance policies for the bridge are outlined in the Sydney Harbour Bridge Conservation Management Plan 1998.
The principal consideration is the protection and maintenance of the steelwork by painting. Protection of the steelwork by painting was extremely thorough during the erection of the bridge. A strategy of spot repair and overall repainting has been used continuously ever since the opening of the bridge and it has protected the steelwork remarkably well since then. The environmental and health hazards associated with lead paints now make their use impossible and the task of maintaining the bridge has been made much more difficult due to the lead already on it. A major question is whether to completely remove the old paint and start from bare metal with modern materials. This is a significant issue as there is a limit to the thickness of paint that can be applied to a surface before it starts to fall off under its own weight and due to degradation over time (Sydney Harbour Bridge Conservation Management Plan, 1998: 114).
The Conservation Management Plan outlines other measures to conserve the integrity of the bridge, including that:
· the clarity of the structural form of the original steelwork be maintained
· priority be given to maintenance of the steelwork
· the original form of the granite-clad pylons and piers be maintained
· the fabric of the rendered masonry approach structures not be obscured or damaged
· the arrangement of internal spaces in the abutments, pylons and approach structures be conserved
· the visual form and setting of the bridge not be obscured by buildings or large plantings on the harbour foreshore
· views and vistas be maintained
· commercial advertising on the bridge be excluded (Sydney Harbour Bridge Conservation Management Plan, 1998: 126-137).
Bradfield Highway, Dawes Point in the south and Milsons Point in the north, comprising bridge, including
pylons, constructed approaches and parts of Bradfield and Dawes Point Parks,
being the area entered in the NSW Heritage Register, listing number 00781,
gazetted 25 June 1999, except that part of this area north of the southern
alignment of that part of Lavender Street between Harbourview
Crescent and Cliff Street, Milsons Point.|
Davis, C W (1980) Images of the Sydney Harbour Bridge unpublished thesis Fine Arts, University of Sydney quoted in The Sydney Harbour Bridge 1932-1982.
Jahn, G (1997) Sydney Architecture, The Watermark Press, Sydney.
Nicholson, J (2000) Building the Sydney Harbour Bridge, Allen & Unwin, Sydney.
Browne, L (1996) Bridges: Masterpieces of Architecture, Universal International, Sydney.
Lalor, P (2005) The bridge: the epic story of an Australian icon - the Sydney Harbour Bridge, Sydney, Allen & Unwin.
Carroll, B (1988) The Engineers, 200 Years at Work for Australia, The Institution of Engineers, Melbourne.
Tanner, H and Dupain, M (1976) Building the Sydney Harbour Bridge: The Photography of Henri Mallard, Sun Books, Melbourne.
Prunster, U (1982) The Sydney Harbour Bridge 1932 – 1982, Angus & Robertson, Sydney.
Heritage Group, Department of Public Works and Services (NSW) (1998) Sydney Harbour Bridge Conservation Management Plan, Sydney, February.
Holder, J and Harris, G (2000) Sydney Harbour Bridge Workers Honour Roll 1922-32 Pylon Lookout Sydney Harbour Bridge, Sydney.
O’Connor, C, Webber, P, Crisp, C, and Fisher, J (1987) Report on the Sydney Harbour Bridge Development Scheme, March 1987.
Lee, R (2003) Australia’s Transport and Communications Heritage Sites: A Study for the Australian Heritage Commission, 2003.
Stone, G (2005)1932: A hell of a year, MacMillan, Sydney.
Australian Academy of Technological Sciences and Engineering, Technology in Australia 1788-1988, Australian Science and Technology Heritage Centre, 2000
(reproduced at http://www.austehc.unimelb.edu.au/tia/426.html)
Godden Mackay (1992) North Sydney Heritage Study Review.
National Gallery of Australia (2006) artonview, Issue No 45, National Gallery of Australia, Canberra, autumn 2006
Sydney Harbour Bridge, The Institution of Engineers, Australia, 2000
Australian Government, Culture and Recreation Portal
City of Sydney, History and Archives
University of Sydney Library, Bradfield’s Bridge
National Library of Australia, Papers of J.J.C. Bradfield, MS 4712, Biographical note http://nla.gov.au/nla.ms-ms4712
(National Library of Australia, http://nla.gov.au/nla.mus-an6631851; http://nla.gov.au/nla.mus-an10787298)
Australian Science and Technology Heritage Centre, Bright Sparcs
St Andrews College, University of Sydney,
University of Sydney, Faculty of Engineering
Newcastle's Bridges and the Tyne River
Bayonne Bridge historic overview
New River Gorge Bridge
Report Produced Fri Jul 11 11:29:21 2014