Work on the French portal of the 35-mile twin rail tunnels under the Cenis Mountain has just begun as part of the planned 170-mile Lyons-Turin railroad. Nearly a fifth of the 100 miles of access and running tunnels have been completed through the Alps on a construction program scheduled for completion in 2032.
From a cut-and-cover approach at Villard-Clément on the French side, a joint venture led by Swiss-based Implenia A.G. has just started forming 1.7 miles of twin tunnels with excavators and drill-and-blast. Excavations will reach a 6.5-mile section of the south running tunnel previously completed for tunnel boring machine (TBM) trials between Saint-Martin-la-Porte and La Praz.
