The Ferden Tunnel in Switzerland, completed by Bouygues Travaux Publics, involved the excavation of the 7.7 km long central section of the Lötschberg twin-tube rail tunnel (approximately 36 km) linking the cantons of Bern and Valais.
This rail line is now used for pendular trains and combined transport. It is part of the vast Alptransit programme for transalpine rail links.
The tunnel was built using a drill and blast excavation method with spoil crushed at the face and mucked out by a system of 40 conveyors. The main characteristics of this projects included: