World Record along the entire route
Sedrun, Switzerland / Schwanau, Germany, March 24, 2011. The miners were both proud and loud as they celebrated the final TBM breakthrough once "Heidi" had cracked the last few centimeters of rock at 12:20 p.m. yesterday. With maximum precision, they reached their target with the S-211 Herrenknecht tunnel boring machine (Gripper TBM, diameter 9.43 m) on the 11.1-kilometer contract section from Faido to Sedrun. The deviation from the target amounted to a mere 3 millimeters vertically, horizontally an absolute precision landing was achieved: 0 millimeters deviation.
Yesterday's breakthrough in Sedrun represents a decisive milestone in this mammoth construction project with operation planned for 2016. The new Gotthard Base Tunnel enables Switzerland to create a monumental, future-oriented construction in terms of transport policy. When finished, the 57-kilometer dual tunnel through the Gotthard Massif will be the longest in the world, bringing Europe closer together along its north-south axis while doubling annual goods transport capacity to around 40 million tonnes.
Following extensive revision work and diameters extended from 8.83 m to 9.43 m, the two hard rock TBMs started off again in the direction of Sedrun in July and October 2007. The Piora Basin was easily passed in 2008 and 2009. During the planning stage for the Gotthard Tunnel, this was the most feared section until it transpired that gypsiferous cap-rock sealed the pressurized sugar-grained dolomite toward the bottom. From March to July 2010 however, boring was halted by rock collapsing in the western tube and the subsequent stabilization measures required. The final breakthrough by "Sissi" in the eastern tube came on October 15, 2010. Anticipated by numerous camera teams, photographers and celebrity guests, the breakthrough was covered live with international media reports sending an astounding echo around the world.
Yesterday's breakthrough celebrations in the western tube were much more low-key and primarily involved the miners and other major project participants. After all, this second breakthrough also represents an end to the "Gotthard era" for the tunnelling teams, claims Renzo Simoni, CEO at AlpTransit Gotthard AG. Like her "colleague" in the eastern tube last year, the next few weeks will see "Heidi" being dismantled and transported back through the tunnel.