Running through the Alps, the Brenner Base Tunnel is a horizontal railway line for the future. The Brenner Base Tunnel is the main element of the new Brenner railway from Munich to Verona. At 64 km, it is the longest underground railway connection in the world, a pioneering work of engineering which will markedly improve passenger travel and freight transport through the heart of Europe.
Work is currently taking place on three construction sites, two in Austria and one in Italy and includes: Tulfes-Pfons; Wolf and the Isarco river underpass.
The Tulfes-Pfons construction lot, worth € 380 million, was awarded to the Strabag/Salini-Impregilo bidding consortium in summer of 2014.
Excavation works began on the project in September 2014, with a completion date currently set for spring 2019. The construction includes 38km of tunnel excavation work.
The process encompasses several structures including Tulfes emergency tunnel, Innsbruck emergency stop with central tunnel and ventilation structures. Main tunnel tubes, connecting tunnels and the Ahrental-Pfons exploratory tunnel will round out the work.
With a value of €104 million, the Wolf construction lot was awarded to the Swietelsky/Swietelsky Tunnelbau bidding consortium in autumn 2013. Excavation work on the Wolf access tunnel commenced in December 2013, and is due for finalisation at the end of 2017.
This construction lot includes not only the developments on the Wolf access tunnel, but also a series of logistics and safety works for the disposal site in the Padaster Valley. Construction consists of the Wolf access tunnel (under excavation), and the following which are complete: a tunnel to re-route the Padaster brook, a spoil tunnel, the debris barrier for the Padaster valley, the intake structure for the Padaster brook, the inner lining for the Padaster tunnel and the inner lining for the Saxen tunnel.
Already completed, the southernmost construction lot of the Brenner Brenner Base Tunnel, worth €301 million Euros – is the Isarco river underpass – which was awarded to the RTI Salini-Impregilo S.p.A., Strabag AG, Strabag S.p.A., CCC soc., Collini Lavori S.p.A. These developments link the Brenner Brenner Base Tunnel with the existing Brenner line and the railway station in Fortezza. Developments have been ongoing since October 2014 and are expected to continue until November of 2022.
The Brenner Base Tunnel (BBT) is the heart of the Scandinavia-Mediterranean TEN Corridor from Helsinki to La Valletta, Malta. Promoting the expansion of this transnational multimodal corridor is the European Union, considering this work to be high-priority.
The BBT is being designed primarily for freight transport, allowing a modal shift of traffic from road to rail – although passenger trains can also travel through the tunnel. Thanks to the virtually horizontal tunnel, train traffic will no longer have to contend with the steep up and downhill slopes on the Brenner railway line that by now is over 140 years old.
Two tubes, with an inner diameter of 8.1 m, run 70 m apart from one another. These tubes are each equipped with a single track, meaning that train traffic through the tubes is one-way. The two tubes are linked every 333 m by connecting side tunnels. These can be used as escape routes in emergencies. This configuration lives up to the highest security standards for tunnels.
A peculiar feature of the Brenner Base Tunnel is the exploratory tunnel running from one end to the other. This lies between the two main tunnels and about 12 m below them. With an inner diameter of 5-6 m, it is noticeably smaller than the main tubes. The excavations currently underway on the exploratory tunnel should provide information on the rock mass and thereby reduce construction costs and times to a minimum. The exploratory tunnel will be essential for drainage and service when the BBT becomes operational.
The slope in the base tunnel is 6.7 ‰ on the northern side and 4 ‰ on the southern flank of the Brenner. The apex height is 790 above sea level, lying 580m below the Brenner Pass itself (1,371m).
For the fourth year running, an Open Tunnel Day was held at the Brenner Base Tunnel construction site in Mules. A grand total of 2,744 keen visitors showed an appearance at the event, proving that interest in the project is as strong as ever.
The day commenced with Holy Mass on the construction site, officiated by Don Paul Valentini and accompanied by the choir of the Mules parish. Subsequently, BBT SE personnel took visitors on guided tours of the tunnel, which took place at regular intervals all day until 5pm, with bilingual guides explaining the status of the works.
Among the various attractions, the “BBT Cinema” was among the most popular, showing films of the Brenner Base Tunnel and documentaries provided by the TV channel RAI Alto Adige and the archives of the Curatorio dei Beni Tecnici Culturali. The materials included a première of the sequences shot by the Austrian photographer Markus Bstieler from the drivers’ cabins of multiple trains on the 2,000 km rail stretch from Berlin to Palermo, the central part of the TEN Scan-Med axis, which includes the Brenner Base Tunnel.