Group

France

Lying between France and Great Britain, the Channel Tunnel provides a completely underground 50 km link, of which 37 km is under the sea. Bored to a maximum depth of 40 m, the cross-Channel “fixed link” has two 7.60 m one-track tunnels and a central 4.80 m wide central services tunnel used for maintenance, ventilation and safety. The two underground switching halls, built to allow trains to transfer from one tunnel to the other, are the largest of their type in world. Part of the Transmanche Link consortium, Bouygues Construction was highly involved in boring the tunnels from the French side and thus actively participated in the construction of the longest undersea tunnel ever constructed using tunnel borers. Seven years of work were required.