TWO HERRENKNECHT tunnel boring machines have been chosen to bore the tunnels on the Alp Transit railway project in Switzerland.
Joint venture tunnelling contractor Tunnel AlpTransit Ticino (TAT), will use the 8.83m diameter gripper machines to bore the Bodio and Faido tunnels for the scheme, which involves more than 52.5km of tunnelling deep beneath the Swiss Alps.
The 2500t, 360m long TBMs will first drive the 13.9km eastern and 14.7km western tunnels from the southern Bodio portal of the Gotthard base tunnel to Faido. The drill cutter head diameter will be increased to 9.33m to drive the 11.6km eastern and 12.2km western tunnels towards Sedrun.
Tunnelling is due to start in October 2002.