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The Millau viaduct
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The technical prowess of the highest bridge of Europe, seen under and upon.
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An unusual story for an exceptional piece of work
From the initial outline plans produced in 1987 to the completion of construction in December 2004, seventeen years of studies and building work were required to complete the missing link in the A75. The Millau Viaduct, that some people are prepared to call the Pont du Gard of the XXI century, represents the successful result of a multitude of stages. The key words were discipline, precision and professionalism at every stage. These same conditions were essential for this exceptional construction to go into the record books.
Three years for a gigantic building site
Concrete…As early as spring 2002, the first piers of the Milllau Viaduct rose skywards. At the same time, the anchorage points for the deck (the abutments) appeared on the limestone plateaux. A few weeks were enough to complete the excavations. Twelve months after work started, pier number “P2” passed the 100m mark. One year later, on 9 December 2003, the concrete building work was completed within the deadline! And, as a bonus, the bridge pier that reached 245 m. took the record for the tallest bridge pier in the world.
SteelAssembling the steel deck began during summer 2002. Two open air construction sites were established, set back from the abutments. On 25 March 2003, a first section of the deck (171 m) set off to conquer the wide open space: the launching operation was a success and 17 others followed at an average rate of one launch every four weeks. On 28 May 2004, at 14:12 precisely, the joining – or placement of the final voussoir– of the northern and southern sections of the deck, was achieved 270 m above the Tarn. Mission accomplished!
Then it all comes together…On 29 May 2004, just 24 hours after the placement of the final voussoir the installation of the pylons began, followed by the setting up of 154 cable-stays to support the deck. In three months, everything was completed. At the end of September 2004, the coating was applied to the deck. Finishing touches were made to the road (painting, security equipment…), the installation of the security and lighting systems, finishing the toll barrier: everything was ready on 18 December 2004 for the commercial operation of the viaduct.
Fourteen years of preparation for a unique adventure
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1987: the first draft plans for the A75, intended to link the Red Limestone Plateau in the North, and the Larzac Limestone Plateau, in the South, were produced. Several proposals were put forward for crossing the Tarn valley, to the east or west of Millau.
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1994: the decision was made. A bridge would be built a few kilometres downstream from the town.
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1996: after a call for tenders, the chosen solution was the one conceived by Michel Virlogeux, Chief Engineer of Ponts et Chaussées, and designed by the architect Sir Norman Foster. A multi cable-stayed work of art was to appear in the Aveyron skies. Its aesthetic qualities and its integration into the landscape convinced the State authorities. This was preferred to four other plans: a bridge of uniform thickness, a bridge of variable thickness, a viaduct with cable-stays stretching under the deck and a single-arch structure.
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1998: the government decided to contract out the construction and the operation of the viaduct. The operational period was set at 75 years.
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2001: in October, following a call for tenders, the combination of concrete (piers) and steel (deck) recommended by the Eiffage group was the one preferred by the State authorities. Concrete possesses all the qualities necessary for endurance. Steel makes it possible to construct a slim-line and lightweight deck. On 14 December, the adventure began when the first stone was laid.
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