Mont Cenis base tunnel will form part of Lyon – Turin high-speed line.
The world’s longest rail tunnel has come one step closer to realization with the start of construction on the Italian section of the Mont Cenis Base Tunnel.
Upon completion, the 57.5 km twin-bore tunnel will be slightly longer than the current record holder, the 57.1 km Gotthard Base Tunnel, and will form the center piece of the 270 km high-speed line between Lyon and Turin that is being built at a cost of €25bn.
Construction of the Italian section of the Mont Cenis Base Tunnel is being undertaken for project organization Tunnel Euralpin Lyon Turin (Telt) by the UXT joint venture of Itinera, Ghella and Spie Batignolles at a cost of €1bn. Work is expected to take 8 years to complete.
Construction of the base tunnel, including the section in France where work has been divided into three lots, will require a total of seven tunnel boring machines (TBM), operating beneath as much as 2,200 m of Alpine rock.
Tunnel Euralpin Lyon Turin announced the delivery of the TBM to the factory in Germany in December.
While the bedrock is considered stable, the sheer weight of the overburden means that rock tends to come loose, posing the risk of the being compressed during construction. Four TBMs have been delivered so far, the latest 334 m-long, 10.4 m-high machine arriving last month.
This TBM will excavate a 18 km stretch of the central section of the tunnel between the Villarodin/Bourget-Modane access adit in France and the Clarea underground safety site in Italy. It will be the first TBM to cross the French-Italian border.
Forming part of the Trans-European Transport Network (TEN-T), the new line between Lyon and Turin will help relieve pressure on cross-border roads.
The new line will enable freight train capacity to be doubled to up to 1,500 tonnes, while passenger journey times will be significantly reduced.
“We are building a piece of Europe,” said Telt chief executive officer, Maurizio Bufalini.
“It is the result of the unceasing work of planners, contractors and local, regional and national public officials without whose effort and determination we would not be here today.”
This news is from International Railway Journal/Jonathan Newton and Tunnel Euralpin Lyon Turin (TELT). Photo courtesy of TELT