Contractors launched the first 8.83m diameter Herrenknecht TBM on the Gotthard Base Tunnel at the beginning of November.
The ceremonial start up of the 3,500kW drive unit, and the turning of the 175t cutterhead, was initiated by the Cantonal government of the Canton Tessin, client AlpTransit Gotthard AG, and contractor TAT (comprising Zschokke Locher/Alpine Mayreder/CSC/Impregilo/Hochtief).
Over the course of the next year, the Herrenknecht gripper TBM S-210, will excavate through gneiss, to secure the eastern tube (approximately 14km) from Bodio to the multi-functional site at Faido.
Before starting the advance at full performance in February 2003, the 410m long, 3,000t TBM will be finely tuned. At the same time, another 8.83m diameter Herrenknecht TBM S-211 will be assembled, which will bore the western tube. This will start in spring 2003. Both TBMs are scheduled to reach Faido by 2005, where they will be disassembled and extended to a larger drilling diameter of 9.33m to allow for the placing of thicker segments.
Afterwards, the machines will excavate the eastern and western tubes, each 11km in length, to the next heading at the Sedrun shaft at the Gotthard tunnel’s mid point.
