Ceneri Base tunnel breakthrough
West bore southern end breakthrough in 2015
The final breakthrough of the western bore of Switzerland's 15.4km Ceneri base tunnel was achieved at noon on January 21, with a deviation of only 2cm horizontally and 1cm vertically.
The final breakthrough of the east tube will take place next week. The entire tunnel has been excavated using conventional drill-and-blast techniques due to the region's complex geology, which ruled out the use of TBMs. The work is being carried out by the Condotte Cossi Consortium.
The twin-tube tunnel will open to commercial traffic in December 2020 as part of the New Railway Link through the Alps (NRLA), which also includes the Gotthard Base Tunnel. Like the Gotthard tunnel, Ceneri's running tunnels are are linked by cross-passages located at 325m-intervals.
Jan 21, 2016International Railway Journal