Wonder of the world
A performing arts centre on Bennelong Point in Sydney Harbour, roofed with tiled concrete shells all cut from one sphere. Jørn Utzon won the design competition in 1957; an Australian team led by Peter Hall finished it, and Queen Elizabeth II opened it in 1973.
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The Sydney Opera House is a multi-venue performing arts centre in Sydney, New South Wales, Australia. Located on the foreshore of Sydney Harbour, it is widely regarded as one of the world's most famous and distinctive buildings, and a masterpiece of 20th-century architecture.
Designed by Danish architect Jørn Utzon and completed by an Australian architectural team headed by Peter Hall, the building was formally opened by Queen Elizabeth II on 20 October 1973, 16 years after Utzon's 1957 selection as winner of an international design competition. The Government of New South Wales, led by the premier, Joseph Cahill, authorised work to begin in 1958 with Utzon directing construction. The government's decision to build Utzon's design is often overshadowed by circumstances that followed, including cost and scheduling overruns as well as the architect's ultimate resignation.
The building and its surrounds occupy the whole of Bennelong Point on Sydney Harbour, between Sydney Cove and Farm Cove, adjacent to the Sydney central business district and the Royal Botanic Garden, and near to the Sydney Harbour Bridge.
The building comprises multiple performance venues, which together host over 1,800 performances annually, attended by more than 1.4 million people. Performances are presented by numerous performing artists, with many resident companies such as Opera Australia, the Sydney Theatre Company and the Sydney Symphony Orchestra. As one of the most popular visitor attractions in Australia, the site is visited by more than ten million people annually, and approximately 350,000 visitors take a guided tour of the building each year. The building is managed by the Sydney Opera House Trust, an agency of the New South Wales State Government.
In 2007, the Sydney Opera House became a UNESCO World Heritage Site, having been listed on the (now defunct) Register of the National Estate since 1980, the National Trust of Australia register since 1983, the City of Sydney Heritage Inventory since 2000, the New South Wales State Heritage Register since 2003, and the Australian National Heritage List since 2005. The Opera House was also a finalist in the New 7 Wonders of the World campaign list.
The facility features a modern expressionist design, with a series of large precast concrete "shells", each composed of sections of a sphere of 75.2 metres (246 ft 8.6 in) radius, forming the roofs of the structure, set on a monumental podium. The building covers 1.8 hectares (4.4 acres) of land and is 183 m (600 ft) long and 120 m (394 ft) wide at its widest point. It is supported on 588 concrete piers sunk as much as 25 m (82 ft) below sea level. The highest roof point is 67 metres above sea-level which is the same height as that of a 22-storey building. The roof is made of 2,194 pre-cast concrete sections, which weigh up to 15 tonnes each.
Although the roof structures are commonly referred to as "shells" (as in this article), they are precast concrete panels supported by precast concrete ribs, not shells in a strictly structural sense. Though the shells appear uniformly white from a distance, they actually feature a subtle chevron pattern composed of 1,056,006 tiles in two colours: glossy white and matte cream. The tiles were manufactured by the Swedish company Höganäs AB which generally produced stoneware tiles for the paper-mill industry.
Apart from the tile of the shells and the glass curtain walls of the foyer spaces, the building's exterior is largely clad with aggregate panels composed of pink granite quarried at Tarana. Significant interior surface treatments also include off-form concrete, Australian white birch plywood supplied from Wauchope in northern New South Wales, and brush box glulam.
The Sydney Opera House includes a number of performance venues:
Planning began in the late 1940s when Eugene Goossens, the Chief Conductor of the Sydney Symphony Orchestra and Director of the New South Wales State Conservatorium of Music, lobbied for a suitable venue for opera and orchestral performance. The Sydney Symphony Orchestra's performance home, the Sydney Town Hall, was not considered large enough. By 1954, Goossens succeeded in gaining the support of New South Wales Premier Joseph Cahill, who called for designs for a dedicated opera house. It was also Goossens who insisted that Bennelong Point be the site: Cahill had wanted it to be on or near Wynyard railway station in the northwest of the central business district.
An international design competition with a grand prize of 5,000 Australian pounds was launched by Cahill on 13 September 1955 and received 233 entries, representing architects from 32 countries. The criteria specified a large hall seating 3,000 and a small hall for 1,200 people, each to be designed for different uses, including full-scale operas, orchestral and choral concerts, mass meetings, lectures, ballet performances, and other presentations.
The jury for the competition were: Professor Henry Ashworth (University of Sydney), Cobden Parkes (New South Wales Government Architect); Professor Leslie Martin (Professor of Architecture of Cambridge University and architect of Royal Festival Hall 1951) and Finnish-American architect Eero Saarinen.
The winner, announced in Sydney on 29 January 1957, was Danish architect Jørn Utzon. Saarinen selected Utzon's distinctive design from a final cut of 30 finalists. Utzon's design was inspired by natural shapes, most notably those of bird wings, clouds, shells, walnuts, rivers and palm leaves.
The runner-up was a Philadelphia-based team assembled by Robert Geddes and George Qualls, both teaching at the University of Pennsylvania School of Design. They brought together a band of Penn faculty and friends from Philadelphia architectural offices, including Melvin Brecher, Warren Cunningham, Joseph Marzella, Walter Wiseman, and Leon Loschetter. Geddes, Brecher, Qualls, and Cunningham went on to found the firm GBQC Architects.
Utzon first visited Sydney on 29 July 1957 along with Erik Andersson who had worked on the competition scheme, to help establish and supervise the developing project. They arrived with a new model of the scheme that was presented at a public meeting Sydney Town Hall on 7 August 1957. They departed Sydney on August 22 headed for Tokyo, planning to return to Sydney in March 1958. His office moved to Palm Beach, Sydney in February 1963.
Utzon received the Pritzker Architecture Prize, architecture's highest honour, in 2003. The Pritzker Prize citation read:
There is no doubt that the Sydney Opera House is his masterpiece. It is one of the great iconic buildings of the 20th century, an image of great beauty that has become known throughout the world – a symbol for not only a city but a whole country and continent.
The Fort Macquarie Tram Depot, occupying the site on the original Fort Macquarie at the time of these plans, was demolished in 1958 and construction began in March 1959. The Opera House was built in four stages: stage I (1957–1959) was planning out the building; stage II (1959–1963) consisted of building the upper podium; stage III (1963–1967) the construction of the outer shells, based upon the image of whales breaching the water; stage IV (1967–1973) interior design and construction.
Stage I started on 2 March 1959 with the construction firm Civil & Civic, monitored by the engineers Ove Arup & Partners. The government had pushed for work to begin early, fearing that funding, or public opinion, might turn against them. But Utzon had still not completed the final designs. Major structural issues still remained unresolved. By 23 January 1961, work was running 47 weeks behind, mainly because of unexpected difficulties (inclement weather, unexpected difficulty diverting stormwater, construction beginning before proper construction drawings had been prepared, changes of original contract documents). Work on the podium was finally completed in February 1963. The forced early start led to significant later problems, not least of which was that the podium columns were not strong enough to support the roof structure, and had to be re-built.
The shells of the competition entry were originally of undefined geometry, but, early in the design process, the "shells" were perceived as a series of parabolas supported by precast concrete ribs. However, Ove Arup & Partners were unable to find an acceptable solution to constructing them. The formwork for using in-situ concrete would have been prohibitively expensive, and, because there was no repetition in any of the roof forms, the construction of precast concrete for each individual section would possibly have been even more expensive.
From 1957 to 1963, the design team went through at least 12 iterations of the form of the shells trying to find an economically acceptable form (including schemes with parabolas, circular ribs and ellipsoids) before a workable solution was completed.
The design work on the shells involved one of the earliest uses of computers in structural analysis, to understand the complex forces to which the shells would be subjected. The computer system was also used in the assembly of the arches. The pins in the arches were surveyed at the end of each day, and the information was entered into the computer so the next arch could be properly placed the following day.
In mid-1961, the design team found a solution to the problem: the shells all being created as sections from a sphere. This solution allows arches of varying length to be cast in a common mould, and a number of arch segments of common length to be placed adjacent to one another, to form a spherical section. With whom exactly this solution originated has been the subject of some controversy. It was originally credited to Utzon. Ove Arup's letter to Ashworth, a member of the Sydney Opera House Executive Committee, states: "Utzon came up with an idea of making all the shells of uniform curvature throughout in both directions." Peter Jones, the author of Ove Arup's biography, states that "the architect and his supporters alike claimed to recall the precise eureka moment ...; the engineers and some of their associates, with equal conviction, recall discussion in both central London and at Ove's house."
He goes on to claim that "the existing evidence shows that Arup's canvassed several possibilities for the geometry of the shells, from parabolas to ellipsoids and spheres." Yuzo Mikami, a member of the design team, presents an opposite view in his book on the project, Utzon's Sphere. It is unlikely that the truth will ever be categorically known, but there is a clear consensus that the design team worked very well indeed for the first part of the project and that Utzon, Arup, and Ronald Jenkins (partner of Ove Arup and Partners responsible for the Opera House project) all played a very significant part in the design development.
As Peter Murray states in The Saga of the Sydney Opera House:
... the two men—and their teams—enjoyed a collaboration that was remarkable in its fruitfulness and, despite many traumas, was seen by most of those involved in the project as a high point of architect/engineer collaboration.
The design of the roof was tested on scale models in wind tunnels at University of Southampton and later NPL to establish the wind-pressure distribution around the roof shape in very high winds, which helped in the design of the roof tiles and their fixtures.
The immensely complex design and construction of the shells was completed by Hornibrook, who were also responsible for construction in Stage III. Hornibrook manufactured the 2400 precast ribs and 4000 roof panels in an on-site factory and also developed the construction processes. The achievement of this solution avoided the need for expensive formwork construction by allowing the use of precast units and it also allowed the roof tiles to be prefabricated in sheets on the ground, instead of being stuck on individually at height.
The tiles themselves were manufactured by the Swedish company Höganäs Keramik. It took three years of development to produce the effect Utzon wanted in what became known as the Sydney Tile, 120mm square. It is made from clay with a small percentage of crushed stone.
Ove Arup and Partners' site engineer supervised the construction of the shells, which used an innovative adjustable steel-trussed "erection arch" (developed by Hornibrook's engineer Joe Bertony) to support the different roofs before completion. On 6 April 1962, it was estimated that the Opera House would be completed between August 1964 and March 1965.
Text from the Wikipedia article “Sydney Opera House”, available under CC BY-SA 4.0.