Blasting starts at Erstfeld

On the NRLA construction site at Erstfeld, blasting for the starter tunnels began on August 29, 2007. In both tunnels, approximately 20 metres were excavated by drilling and blasting. Blasting will continue until the end of October 2007.
With overhaul and assembly of the tunnel boring machines at Erstfeld now at an advanced stage, work has begun on the starter tunnels. The necessary 20 metres were first excavated in the east tunnel, then in the west tunnel. To reduce disturbance to neighbourhood residents as far as possible, blasting is only taking place during the daytime and on a small scale each time.
The starter tunnels with a length of a good 20 metres are needed for the tunnel boring machines to first brace their so-called grippers against the side walls so that mechanical driving can then begin. In the east tunnel, the tunnel boring machine will start driving at the beginning of December 2007, and in the west tunnel in February 2008. Both tunnel boring machines will begin driving at full capacity in spring 2008.
The main contractor on the Erstfeld construction site is the AGN Lot 151 Consortium comprising Murer-Strabag AG, of Erstfeld, Switzerland, and Strabag AG, of Spittal/Drau, Austria. The work comprises driving the two single-track tunnels of the 7.8-kilometers-long Gotthard Base Tunnel section from Erstfeld to Amsteg, excavation of 23 connecting galleries, and construction of the underground branch-off for subsequent implementation of an underground connecting route.