Boring started at the beginning of last month on the eastern tube of the Gotthard Base Tunnel North, in Amsteg, Switzerland.
The 9.58m diameter Herrenknecht Gripper TBM will take five years to excavate the 11.4km east tube to Sedrun. Next month, the second identical machine will start boring the west tube.
The AGN JV (comprising Murer AG and Strabag AG) will operate the machines, hoping to achieve an average advance rate of 10.4m/day. Maximum daily performances may reach up to 40m/day. The 57km long twin-tube Gotthard Base Tunnel will be the longest rail tunnel in the world, with 50km constructed using TBMs. The rest will be drill and blast.
A total of four Herrenknecht Gripper TBMs will be operating at the Gotthard Base Tunnel, all fully equipped to excavate and secure the rock.
The back-up installations, provided by Rowa Tunnelling Logistics, include: a monorail suspended railway for the constant supply of shotcrete and free access to the lower construction area; a stone breaker and conveyor belt; an uninterrupted double-track service to the bottom construction area; and a mobile shotcrete robot on the upper level with a working area of 360 degrees.
The client is AlpTransit Gotthard AG.
