German manufacturer Herrenknecht has scooped the award to supply two TBMs for the construction of 52.5km of tunnel on one of the world’s longest underground excavation projects, the 2x57km long Gotthard railway tunnels in Switzerland (T&TI, October 2000, p21).

The contract award in August saw Herrenknecht beat off competition from US manufacturer Robbins and German company Wirth.

The single gripper machines, supplied at an undisclosed price, will be used to build the eastern and western drives on the Bodio (Lot 554) and Faido (Lot 452) sections.

The $823M construction contracts for Bodio and Faido were awarded to TAT, a joint venture of Zschokke Locher/Alpine Mayreder Bau/CSC Impresa Constructioni SA/Impregilo/Hochtief in June this year by client AlpTransit Gotthard.

TAT, in turn, awarded the production, delivery and assembly contract for two 8.8m diameter TBMs to Herrenknecht telling T&TI that it was "the long and good experiences with the manufacturer" that helped seal the contract.

The 2,500t, 360m long machines will first drive the 13.9km long eastern and 14.8km long western tunnels on the Bodio contract from the Bodio portal towards Faido. Excavation is due to start in October 2002 with completion scheduled for April and July 2005 respectively.

Once the Bodio tunnelling has been completed, TAT will have a 180 day period to increase the 8.8m diameter drill cutter head to 9.3m diameter. This is being done to allow a thicker, final concrete lining, needed as the tunnel depth increases from 1,000/1,500m on Bodio to 2,000m on Faido.

December 2005 is the scheduled start for the 11.6km long eastern Faido drive with the 12.2km long western tunnels beginning in March 2006. Tunnel boring on this section towards Sedrun is expected to be completed by November 2008.

Both machines are being manufactured in the company headquarters at Schwanau, Germany and will be assembled underground on site.

At 2x57km long, the Gotthard railway tunnels will be the world’s longest, and when complete will form a major part of the ambitious $17bn AlpTransit scheme in Switzerland.

Related Files
Gotthard base tunnel