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Brenner Base Tunnel

Brenner Base
Written by Roma Publications

Brenner Base Tunnel

The Brenner Base Tunnel (BBT) is a straight and flat railway tunnel connecting Austria and Italy, through the base of the Eastern Alps beneath the Brenner Pass. In 2004, Austria and Italy signed a State Treaty to build the BBT, and construction work began in 2008.

According to the construction programme, it is set to be completed by 2027 and then a year of test operations will run, meaning the tunnel should be fully operational by 2028.

It 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 set to improve passenger travel and freight transport through the heart of Europe in the years to come.

The European Union is promoting the expansion of this transnational multimodal tunnel and considers this work to be high-priority. The BBT is meant primarily for freight transport, allowing a modal shift of traffic from road to rail. Passenger trains can also travel through the tunnel. In addition, 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 150 years old.

The Brenner Base Tunnel is actually a tunnel system made up of total of about 230 km of tunnels, but the railway line will run for 64 km.The BBT consists of two tubes, each 8.1 m wide, running 40-70 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 in emergencies as escape routes. This configuration conforms to the highest security standards for tunnels.

A peculiar feature of the Brenner Base Tunnel (BBT) is the exploratory tunnel running from one end to the other. This tunnel lies between the two main tunnels and about 12 m below them and with a diameter of 5 m 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. Furthermore, the exploratory tunnel will be essential for drainage when the BBT becomes operational.

A new rescue tunnel was being built running parallel to the existing bypass. The two-tube tunnel system between Innsbruck (Austria) and Fortezza(Italy) is 55 km long.

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 790m above sea level, lying 580 m below the Brenner Pass itself (1,371 m).

Recent Updates

15 years ago, The State Treaty was signed in Vienna and at the end of 2004 BBT SE was established as a project vehicle to start the planning phase and then carry out the works.

The 15th anniversary of the Treaty was marked by a milestone: 100 km of tunnels have been excavated. 100 km of tunnels have been completed, including over 38 km of exploratory tunnel, 28 km of railway tunnels and 34 km of other tunnels.

The State Treaty provided that Italy and Austria would provide in equal measure the costs of building the tunnel (total costs so far are at 8.384 billion Euros). The support of the European Union is extremely important; with steady increases in the percentage of co-financing, the EU has always contributed to the project and is its most important source of funding.

As the EU Commissioner for Transport, Violeta Bulc, said:

“The Brenner Base Tunnel project is a flagship project that will not only bring the European States closer, but make these linked economies more efficient and competitive.”

The tunnel is still on schedule to be operational by 2028. For further information, visit:

Brenner Base

Zufahrtstunnel Wolf Vorbereitung Sprengung 22.06.2015 by Foto Berger

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