Engineering and architectural features of the Millau Viaduct

Milau Viaduct

Stepping Out on a Twenty-First Century Bridge in the Sky: The Milau Viaduct Over the River Tarn

The World's Tallest Bridge

With a central pier stretching three-hundred and forty meters above the floor of the valley carved by the River Tarn over the eons, the Milau Viaduct bridge in southern France is the tallest bridge meant for automobile traffic in the world, stretching taller than the Eiffel Tower in Paris and falling a mere forty meters short of the Empire State Building's impressive height (Discovery 2010). With a total of four lanes of traffic (one lane and one full safety lane per direction of and a total span of two-and-a-half kilometers, the bridge is impressive in all of its dimensions, standing as a staggering achievement of the twenty-first century that could hardly have been dreamed of even a few short decades ago (Bridgepros 2010). The practical boon that this bridge brings for folks traveling the Paris-Barcelona route or to destination in between or beyond is also a tremendous feature worthy of comment.

It is not simply in the practicalities of the Milau viaduct bridge that it exceeds previous expectations and thoughts of possibility. Despite the amazing height and length of this structure, and the enormous amount of materials and labor that went into its construction, the ultimate results is an engineering marvel that is light, airy, and even delicate in appearance (Discovery 2010). The aesthetic qualities and achievements that the bridge represents are equal to the engineering as a testament to the passion and the expertise of the bridge's creators.

Both the architectural and the engineering features of the bridge are truly revolutionary and yet classically inspired and timelessly stunning. The safeguards embedded in the design and construction of the bridge have led the builders to guarantee their work for one-hundred-and-twenty years, and despite the structure's height and span it is expected to be completely safe in any earthquake and severe windstorms, standing against the elements untarnished (StateMaster 2010). At the same time, it stands with the elements as far as its aesthetic design, with seven truly massive yet seemingly too-slender reinforced concrete posts rising liking ancient monoliths from the floor of the River Tarn's valley, and delicate strands like so many spider's strings spreading from the peaks of the pillars to hold up the roadway underneath, which like the cables is painted the most perfect white possible (Discovery 2010). The overall effects is a bridge that almost seems to be floating, and one almost hopes that it is due to the seeming insubstantiality of its creation.

This, of course, was the exact purpose of the bridge's designers and builders. Well, perhaps not the slight hesitation that many might feel as their side windows suddenly become full of nothing but sky whilst traversing the airy tightrope that is the Milau Viaduct bridge, but certainly the deceptive and non-intrusive unmistakable and unavoidable beauty of this structure that still retains function as the truly paramount feature.

It is through the spirit and the imaginations of the bridge's creators that the Milau Viaduct bridge came into existence with the grace and purpose that it carries, and indeed without the right individuals having become involved in this project early on there might not be a bridge where one stands so prominently today (Glancey 2004). It is often the case that genius and fate coincide fortuitously to provide the world with new marvels at which to wonder, but despite the repeated occurrence of this coincidence over the thousands of years of human history and innovation, it never ceases to be exciting. A deeper appreciation of this bridge and the engineering and architectural accomplishments that are inherent to it is derived form an understanding of the men who made its creation possible.

You May Say I'm a Dreamer

Norman Foster founded Foster + Partners, his architectural form, in 1967, and over the four decades of its operations this company has grown to a worldwide entity with over twenty project offices across the globe (Foster + Partners 2010). Born in Manchester, England in 1935 and graduating from the Manchester University School of Architecture and City Planning in 1961, Foster's immense talent was recognized early on with a Henry Fellowship to Yale University, where he earned his Master's Degree in Architecture (Foster + Partners 2010). His prestige and renown would only grow from this point on.

With his company, though always under his own watchful eye, Foster + Partners has designed airports, civic buildings, urban masterplans and public infrastructure systems, and a variety of other public and private projects of a generally immense scale (including the largest single building in the world, the Beijing Airport) (Foster + Partners 2010).

Awarded the 21st Pritzker Architecture Prize in 1999 and the Praemium Imperiale Award for Architecture in 2002, Foster has been awarded many other prestigious honors by the architectural community and is also both a knight and a Lord of the English realm (Foster + Partners 2010). The Milau Viaduct bridge was the perfect project for this man who likes to dream big, and who likes to see his dreams turned into realities -- and has the wherewithal to do it.

But I'm Not the Only One

In the same year that Norman Foster was founding his architectural firm, Michel Virlogeux was graduating from the Ecole Polytechnique, moving to the Ecole Nationale de Ponts et Chaussees from which he graduated in 1970 (ArchInform 2010). He began his practical work as a civil engineer in Tunisia immediately thereafter, while at the same time earning his Engineering Doctorate from the Piere et Marie Curie University (ArchInform 2010). After completing both his doctorate and his work in Tunisia, Virlogeux returned to France and joined the technical department of the French Highway administration (ArchInform 2010).

Though this might not seem as exciting or as romantic as establishing an independent architectural firm in London and tackling projects all over the world, as Head of the Large Concrete Bridge Division -- another position that is more exciting then it sounds, which he achieved in 1980 -- Virlogeux deigned over one-hundred different bridges, and his Normandy Bridge held the world record for the longest cable=span bridge for four years (ArchInform 2010). It was after leaving the French Highway Administration in 1995 that Virlogeux became involved in the project for which he is best known, including the Vasco de Gama Bridge in Lisbon in addition to the Milau Viaduct bridge (ArchInform 2010). This project, in his native France, is sure to be one of the most lasting testaments to the power that both Virlogeux and Foster possess as architects and engineers.

The Road to the Bridge

The mere existence of these two men and there remarkable talents was not, of course, sufficient to force the Milau Viaduct bridge's spontaneous existence, but first years of debate had to be held before the possibility of there being any bridge emerged. In response to the growing needs of the Milau area of France, and for the traffic passing through southern France generally, four different options had been developed and debated in the 1980s for transportation routes that would effectively handle the rather difficult geographical issues that existed (StateMaster 2010).These routes included several that would either bypass the massive valley of the River Tarn almost entirely, or that would use lengthy winding roads to descend and ascend the walls of the valley rather than attempting the feat of spanning the valley from the heights on either side (StateMaster 2010). Ultimately, the current route was chosen as it best served the needs of the Milau area itself and provided greater convenience of travel for all concerned -- provided a bridge could be built (StateMaster 2010).

The route as adopted, in fact, allowed for the abandonment of any bridge project, resorting to switchback roads and long descending and ascending trips, is a bridge did not appear to be economically and/or practically feasible. In the staunch tradition of French bureaucracy -- one of their most successful exports -- this took another six years of discussion amongst politicians and engineers, as well as the review of proposals and the conducting of initial studies by dozens of civil engineers and architects (StateMaster 2010). Virlogeux oversaw much of this process from his position within the French Highway Administration, and ultimately different sets of architects and engineers were given the tasks of conducting technical and architectural studies, determining how a bridge could possibly be built across the entire valley of the River Tarn without causing a massive eyesore and possibly a very real impediment to the people and wildlife living on the valley floor below (StateMaster 2010). A design, with the technical specifics supplied by Virlogeux and the architectural design and detail supplied by Foster, received final approval after several adjustments in 1998, and the construction of the bridge progressed rapidly from that point (StateMaster 2010).

A Combination of Strength and Grace

Over nineteen-thousand tons of steel were used simply to reinforce the concrete out of which the Milau Viaduct bridge is primarily constructed; this number seems briefly more believable when it is learned that over eight-five thousand meters of concrete -- enough to fill London's Albert Hall -- went into the construction of the bridge (Discovery 2010). To put this in better perspective, the average driveway requires between six and seven meters of concrete, meaning there is well over twelve-thousand driveways' worth of concrete stretching out for two-and-a-half kilometers over the valley of the River Tarn, at times higher than the Eiffel Tower and most of the buildings in New York City (BridgePros 2010). All of this material went to good use, creating not only the tallest vehicle bridge in the world, but also one of the safest and most assuredly long-lasting (BridgePros 2010).

Yet despite the football-stadium's worth of concrete and steel somehow suspended in the skyline of southern France, there is a tremendous and awe-inspiring beauty to the Milau viaduct bridge that defies the massive scale of the project. From this plan's initial design phases, the bridge was meant to be an epic and lasting work of art, and it was incredibly successful in attaining this goal (Glancey 2004). The lightness and seeming (and literal, in fact) suspension of the bridge is breathtaking in aerial views and awe-inspiring in majesty from the ground (Foster + Partners 2010).

Aside from the sheer massiveness and height of the bridge, there are many other features of both its architectural and its technical design that make this bridge both scientifically and culturally noteworthy. Part of the bridge's grace and the strength and practicality of its design is derived from the fact that it does not simply jut straight across the River Tarn valley skyline in a horizontal slash, but actually forms a graceful and sloping curve from one side of the valley to another. The radius of the curve -- the distance from the hypothetical center of the circle of which the Milau Viaduct bridge comprises a section to the bridge itself -- is approximately twenty kilometers, making the curve very gently and hardly perceptible while actually traversing the roadway, but this curve actually help drivers have better visibility along the span of the bridge as they move along (StateMaster 2010). The subtle downward slope that occurs from north to south is a natural result of the different heights of the valley walls at the point decided optimum for the bridge, and adds to the aesthetic grace of the bridge as well by making it appear almost a part of the natural flow of the landscape.