A 50:50 joint venture of Italy’s Webuild and Swiss builder Implenia has won €651m contract to build Lot H41 (Sill Gorge to Pfons) of the Brenner Base Tunnel, the 55km, twin-tube rail tunnel planned to connect Austria and Italy under the Alps.
The client, BBT SE, the public limited company developing the tunnel, tendered Lot H41 in January this year. Described as the northern portal of the base tunnel, the section runs from Sill Gorge near Innsbruck south to the town of Pfons in the Austrian state of Tyrol.
The ceremonial start of excavation was celebrated on 28 October at the foot of the Viller Berg mountain at Sill Gorge.
“Compared to other construction sites of the Brenner Base Tunnel, the construction lot at the Sill Gorge is rather small but very important, as it is visible from Innsbruck and therefore visible to the people,” Gilberto Cardola, BBT chief executive, said at the time. “As Europe’s cross-border gate, once completed the BBT will ensure faster transport of passengers and freight from north to south and vice versa.”
According to Implenia, the project’s technical lead, some 5.7km of tunnelling will be excavated by drilling and blasting and some 16.4km with tunnel boring machine.
The JV will build the tunnels’ inner lining as well as the Innsbruck emergency stop and an exploratory tunnel. Creating around 400 jobs in the region, work is scheduled to take 80 months.
The base tunnel consists of two tubes, each 8.1m wide, running 40-70m apart from one another, according to BBT SE. Each tube will have a single track. The two tubes are linked every 333m by connecting side tunnels for escape routes.
A unique feature of the base tunnel is the 5-metre-diameter “exploratory tunnel” running end to end between, and about 12m below, the two main tubes. As its name suggests, the exploratory tunnel us intended to provide advance data on rock mass to facilitate tunnel construction.
Implenia and Webuild are already working together on the southern connection to the Brenner Base Tunnel with the high-capacity line between Franzensfeste and Waidbruck. Lot H41 is Webuild’s fourth contract on the base tunnel.
Erwin Scherer, Global Head Tunnelling at Implenia, said: “The Brenner Base Tunnel is an important part of the Scandinavia-Mediterranean corridor within the Trans-European Network (TEN-T), which is improving railway connections throughout the whole continent. We’re very happy that we can bring our many years of experience and our proven expertise in tunnel construction to this large and complex tunnelling project.”