A new route for the Mont Saint-Michel
In order to prevent the build up of sand around the Mont Saint-Michel (Manche), “a wonder of the western world”, a bridge is under construction between the rocky island and the mainland since February 2012. It will replace the old causeway which impeded the currents of the Couesnon river and encouraged the deposit of sediments carried by the tides.
The metal structure, a material that combines both strength and flexibility, was designed by the architect Dietmar Feichtinger to be the thinnest possible link between the abbey and the mainland.
The bridge is 756 metres long and varies in width between 10.9 and 17.2 metres (divided between the road which spans 3.5 to 5.8 metres and the pedestrian footpath which spans 6.4 to 9.4 metres). The structure requires 2,000 tons of metal framework. This is mounted on steel poles which replace the concrete supports used in traditional bridges.
The first 12-metre sections, which were manufactured at the Eiffage Construction Métallique Lauterbourg factory (Bas-Rhin), were installed on June 12th. At a rate of two per week, the structure will be completed by July 2013.
Eiffage Travaux Maritimes et Fluviaux (ETMF) is responsible for the concrete slabs that will line the bridge, as well as the abutments at each end to ensure the transition onto land. The subsidiary is also building a wastewater pumping station and a fire-fighting reservoir. As usual, ETMF will be up against the familiar challenges of the tides. Delivery is scheduled for early 2014.