The world’s longest tunnel, Switzerland’s 57-kilometer-long Gotthard Alpine rail crossing, broke through on Oct. 15. The Gotthard twin tunnels will be the longest of several being built through the Alps on the Milan, Italy, to Basel, Switzerland, corridor.
The joint-venture Tunnel AlpTransit-Ticino (TAT) broke northward from its Faido section of the east drive into the awaiting Sedrun stretch, roughly halfway along the tunnel. The west tunnel’s breakthrough is scheduled for next spring. TAT used 8.8-meter-dia Herrenknecht Gripper tunnel-boring machines for most of the excavation.
Because of difficult ground conditions on the south drives, including the Faido and Bodio sections, the tunnel is expected to start rail operations late in 2017.
“Problems began in April 2002, a few days after starting excavation,” recalls Heinz Ehrbar, chief construction officer at AlpTransit Gotthard A.G., the owner. “They ended in the tunnel … in summer 2008. Two years’ delay and an additional $525 million were the consequence.”
However, opening the tunnel to rail services at the end of 2016 “is feasible,” adds Renzo Simoni, the company’s chairman. He forecasts the total cost to be $10.3 billion.
The TAT joint venture is working on over half the tunnel length from the south portal at Bodio. Lead by Zschokke Locher A.G., Zurich, the team includes Alpine Mayreder GmbH, Salzburg, CSC Impresa Costruzioni S.A., Lugano, Impregilo S.p.A., Milan, and Hochtief A.G., Essen.
The adjacent Sedrun section is in the hands of the Transco-Sedrun joint venture, led by Batigroup A.G. Tunnelbau, Zurich. Other members include Frutiger A.G., Thun, Bilfinger & Berger Bau A.G., Munich, and Pizzarotti S.p.A. Parma. Austria’s Strabag A.G., Spittal an der Drau, is handling the northern drives to the Erstfeld portal.