What is hidden under the Cheviré bridge? Discover the inside of a road viaduct, a place forbidden to the public

Actor Alexis Ziane investigates a place that is forbidden or rarely open to the public: the Cheviré bridge in Nantes. A busy road viaduct that crosses the Loire. Enter its bowels and follow the guide.

The Pont de Cheviré, a majestic viaduct, is a vital artery for Nantes. It facilitates traffic between the north and south of the Loire, reducing travel time for motorists and freight carriers. Initially planned to accommodate 40,000 vehicles per day, its traffic has almost tripled.

More than 100,000 vehicles pass through it every day, often unaware of the mysteries hidden beneath their wheels. Actor Alexis Ziane takes us into this little-known world, closed to the public.

Under the roadway of the Pont de Cheviré, there are 1,500 meters of technical galleries, a space closed to the public and jealously guarded to prevent intrusions.

In the past, individuals have managed to enter the bridge, forcing the access to the piers to be blocked.

William Huitric,

head of the engineering works management center at the DIRO (West Interdepartmental Roads Directorate),

This dark and poorly lit concrete gallery is the scene of constant activity. Teams regularly intervene there for inspections and maintenance work.

Every month, buckets of earth and rubbish, lost by vehicles on the road, are evacuated via a trapdoor using a winch. The bridge is also a crucial passage for optical fibre, linking the north and south of the Loire.

Another challenge facing DIRO professionals: pigeons. Attracted by a nearby grain silo, these birds have found refuge in the corners of the bridge and their corrosive droppings threaten the metal structures. To protect the infrastructure and ensure the safety of motorists, one to two pigeons are captured each month and released elsewhere.

The construction of the Pont de Cheviré dates back to the 1980s. After several proposals, it was under the mandate of Michel Chauty, mayor of Nantes from 1983 to 1989, that the decision was made to build a viaduct.

Philippe Fraleu, the architect, had to meet three major challenges: allowing the passage of the three-masted Belem, respecting a maximum height of 91 metres imposed by the proximity of Nantes Atlantique airport, and dealing with different geological terrains between the north and south banks.

The most spectacular moment in the construction of the Pont de Cheviré was the installation of the central span. This section, 242 metres long and weighing 2,200 tonnes, was built in Saint-Nazaire before being transported by barge to Nantes. It took 27 hours to raise and install it, a feat of engineering that has left its mark.

The work, started in 1986, lasted 52 months. The bridge was inaugurated on April 27, 1991 by Michel Rocard, then Prime Minister. The initial cost, estimated at 275 million francs, almost doubled to reach 522 million francs, or 128.1 million euros today. Funded 55% by the State and the rest by the Syndicat Intercommunal à Vocation Multiple de l’Agglomération Nantaise, the bridge was initially expected to support 40,000 vehicles per day, a number which has since tripled.

LA confidential is a webseries which explores places forbidden to the general public and ultra-controlled, such as sewers, or museum reserves, in Loire-Atlantique. An actor takes you to meet the professionals responsible for maintaining and monitoring the site.

VLIPP team, the Nantes student media:

Director: Augustin Flepp

Actor: Alexis Ziane

Cinematographer: Fabien Dolbeau

Framing: Margaux Bannwarth

Aerial shot: Vincent Schaub

Sound: Marcelin Brisard

Editing: Augustin Flepp and Margaux Bannwarth

Graphic designer: Pierre Lemboli

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