The world’s tallest bridge that transformed European country and cost £20mn to build

The world’s shouldn’t have been possible and was critiqued for decades by the French government, hailed as an impossible milestone for both architects and engineers. 

The technique was so innovative that nobody thought it would actually be successful. 

The Millau Viaduct now stands 340m tall and stretches 24,60 meters long. 

The bridge was so pivotal it

In all of Europe there are only 4 skyscrapers taller than it, so prominent it can even be seen from space.

This is all thanks to the brilliant minds of English architect Norman Foster and engineer Michel Virlogeux. 

“I was absolutely terrified. I was physically sick with apprehension. Was it the right decision?” Lord Norman Foster told the B1M, in an interview to celebrate the 20th anniversary of the bridge’s opening. 

The Massif Central is a beautiful mountainous terrain that covers about 15% of France, which, as you guessed, is smack bang in the middle.

These gorges, rivers and forests made it an incredibly hard landscape for anyone to cross.

Those travelling from the Paris city to the south of France during the summer months, or from northern Europe to Spain, found this journey difficult to navigate and rather time consuming.

This divided Europe for centuries.

Central France couldn’t evolve due to a lack of adequate transportation links, and the ones they did have in place were single lane and would have to dip and rise into these steep valleys or make detours.

It also made the villages in this area disconnected from the outside world, Millau being one of them.

Millau is a beautiful place surrounded by picturesque countryside.

The days before the bridge, this small village was one of the worst bottlenecks in Europe.

The congestion would add 5 hours to the trip and stretch 20km in both directions.

It wasn’t until the 1980s, the French government decided it was time to tackle this issue.

They started off tangible, with a few massive freeways.

Millau however still posed many problems.

Should they bypass it all together? Build a bridge over Tarn river? The terrain was prone to landslides and stretched out wide.

Geologists and specialists worked for years trying to figure out where exactly they should be placing this bridge.

This was when Engineer Michel Virlogeux had a lightbulb moment – What if the road didn’t go into the valley at all, what if it went directly over it ?

His idea was bold and had never been done before.

The government thought the idea was insane, so laid it to rest.

It was then again in 1994, Virlogeux had successfully completed the Pont de Normandie.

The cable-stayed road bridge spans the river Seine linking Le Havre to Honfleur in Normandy, northern France.

The bridge’s completion was enough to convince the French government to build the Millau.

Before commencing the construction, Virlogeux had one condition – the bridge had to be beautiful. Not taking from the landscape but adding to it.

This was where Lord Foster came in.

It wasn’t common for architects to be involved in projects involving national infrastructure but he explained that the government realised this project was environmentally sensitive, so “there should be from the outset a visual aesthetic coupling to the engineering.”

They decided a cable- stayed bridge would be most efficient at carrying heavy loads, and would be able to support a more slender deck, making it more aesthetically pleasing.

Lord Foster even reduced the number of piers from 9 to seven that Virlogeux had initially proposed.

This was more than a bridge, it was an extension of the land.

Once plans for the bridge were officially announced, there was outcry from locals and environmentalists.

Like Lord Foster, many feared that the natural beauty would be ruined by a bridge so large, it topped the eiffel tower.

Since there would be no other tall buildings around the bridge to scale it, it would look even more gigantic.

To balance this Lord Foster wanted the piers to disappear into the sky. “The idea that the column is faceted and is like a tuning fork and you can see through it that was simultaneously visually slimming it, but at the same time responding to the expansion and contraction in a more economic way”

So as the towers rose, they would get more slender and divide into two prongs.

This solved not only the aesthetics issue, but also served another purpose.

It tackled the wind issue.

Wind speeds could blow through the Tarn Gorge at more than 130 miles an hour.

The two prongs in each of the piers allowed for the deck above to move but be stable while the wind could pass through the gaps.

It also allowed for the deck to expand and contract as metal does on warmer days.

The team compromised with a span of 342 metres in between each pier, all of which, taller than a skyscraper, using GPS technology to place each one.

The project engineers sunk these deep into the valley’s bedrock and covered them with reinforced concrete.

The deck was made from hollow steel and was prefabricated in sections.

Each section was then floated down the Rhine, to the Mediterranean, to the French coast, and then driven by road to the construction site

The deck was then slid across the completed towers using enormous hydraulics that pushed them across the valley bit by bit every day.

They were then launched simultaneously from both sides over temporary structural supports.

The road opened up this area of France, forever changing the map of Europe.

Within three years, the bridge had paid for itself.

The detour also saves around 40,000 tons of CO2 emissions from heavy goods vehicles alone, the equivalent of 40,000 trees absorbing emissions over 40 years.

In the end, the architects and engineers were able to achieve remarkable results.