Frejus Survey – Frejus Tunnel Monitoring

Inspection and monitoring support for the Frejus Tunnel and its underground duct system.

Opened in 1980, the Frejus Tunnel extends for over 12 kilometers. In compliance with EU safety regulations for tunnels within the TEN-T network, a second tunnel tube has recently been completed. The survey activities focused primarily on the inspection of the interconnecting bypasses between the two tubes.