Start of second tunnel boring machine in Gotthard Base Tunnel North

On Tuesday, August 19, 2003, on the construction site at Amsteg of The AlpTransit Gotthard Company, the second tunnel boring machine for mechanically driving the Gotthard Base Tunnel on the north side of the Alps started operation. Between now and 2008, it will drive the west tunnel through 11.4 km of rock to Sedrun.

Mounted on the approximately 440-metres-long tunnel boring machine (TBM) are all the equipment needed to excavate the rock and secure it. Like its "colleague", which has been at work in the east tunnel since the end of May 2003, the TBM will first "warm up". Driving at full capacity will start in January 2004. The daily rate of advance after that will depend on the geological conditions. Based on the forecasts, an average advance of 10.4 metres per working day is expected. Under optimal conditions, maximum daily advance rates of 35 to 40 metres can be achieved. A total of 50 of the 57 kilometres of the Gotthard Base Tunnel will be constructed with TBMs.

The TBM was ordered by the AGN Consortium (Murer AG, Erstfeld, and Strabag AG, Spittal/Drau, Austria) from Herrenknecht of Schwanau, Germany. After the single-gripper tunnel boring machine with a diameter of 9.58 m and a weight in excess of 3,000 tonnes had been constructed, it was tested for acceptance at the manufacturers, then dismantled and transported in some 90,000 individual parts to Amsteg. The main drive, which weighs 117 tonnes, had to be transported from Lucerne to Flüelen by barge, because the load was too heavy for some sections of the A2 motorway. Since May 2003, the TBM has been assembled underground in the west installation cavern. The backup train of the TBM was supplied by Rowa Tunnelling Logistics AG, of Wangen/Schwyz. It contains all the logistical installations needed for the drive.