Today's ceremonial breakthrough of the exploratory tunnel in the Brenner Base Tunnel marks an event of historic significance. Austria and Italy, together with the European Union, are celebrating this decisive step forward in one of Europe's most important railway infrastructure projects.
In the presence of numerous high-ranking personalities and around 1,000 guests – led by the European Commissioner for Sustainable Transport and Tourism, Apostolos Tzitzikostas, the directors of DG Move, Herald Ruijters and Eric von Breska, the Italian government, represented by Prime Minister Giorgia Meloni and Deputy Prime Minister and Minister of Transport Matteo Salvini, the Austrian federal government, represented by Federal Chancellor Christian Stocker and Minister of Transport Peter Hanke, the Governors of Tyrol, Anton Mattle, and South Tyrol, Arno Kompatscher, as well as the member of the Executive Board of Austrian Federal Railways, ÖBB-Infrastruktur AG, Judith Engel, the Executive Board of Italian State Railways Rete Ferroviaria Italiana (RFI), Aldo Isi, the Regional Councillor for Transportation of Tyrol, René Zumtobel, and South Tyrol, Daniel Alfreider, the Italian and Austrian supervisory board members of BBT SE, and representatives of the construction companies from both countries – this historic moment was celebrated with great dignity.
The breakthrough at the national border under the Brenner Pass underlines the role of Austria and Italy as driving forces behind a sustainable, modern and future-oriented transport policy.
Breakthrough of the exploratory tunnel at a depth of around 1,400 metres
In tunnel construction, a breakthrough is one of the most emotional moments – a moment that everyone involved in the project has been working towards for a long time. At exactly 2.30 p.m., EU Commissioner Tzitzikostas, Prime Minister Meloni, Federal Chancellor Stocker and the two transport ministers pressed the start button together.
There was tense anticipation in the construction lots H53 Pfons-Brenner (Austria) and H61 Mauls 2-3 (Italy). While the miners and project teams waited underground for the big moment, the guests at the festival tent set up in the village of Brenner were able to follow the events live. Then the moment arrived: Amidst loud cheers, the miners broke through the tunnel wall with a chisel excavator at a depth of around 1,400 metres below the Italian-Austrian border at the Brenner Pass. The teams approached each other, greeted each other and embraced. The guests celebrated this moment with thunderous applause. It was a unique moment that impressively demonstrated teamwork, technology and international cooperation.
The exploratory tunnel: A unique feature of the project
The exploratory tunnel of the Brenner Base Tunnel is a unique feature of this construction project. With a length of around 57.5 kilometres, it is one of the longest of its kind in the world. It is not intended for train traffic, but is to be used for technical aspects such as pre-excavation geological prospection, material transport, service and maintenance purposes, and can also be used as an escape route in case of an incident.
The high-precision surveying is particularly noteworthy: the section up to the Brenner was driven from two sides – the Wolf and Mules access tunnels. For the approximately 29 km long route, the deviation is in the impressive single-digit centimetre range. Thanks to this accuracy, it was possibile to build the subsequent main tunnel tubes without any costly adjustments.
This concept of a separate exploratory tunnel, which acts as a ‘trial run’ for the actual Brenner Base Tunnel, is unique worldwide in terms of its length and precision and underlines the high-tech nature of the project. The exploratory tunnel is located centrally beneath the two main tunnels, at a depth of around 10 to 12 metres.
"Today, Europe is growing closer together through Italy and Austria,’ explained the two members of the BBT SE Executive Board, Gilberto Cardola and Martin Gradnitzer. The Brenner Base Tunnel is more than just a structure – it is a symbol of the European idea, driven by determination and years of intensive cooperation. The past few years have been challenging, but as a management team we have made this milestone possible. We would like to express our heartfelt thanks to the miners and everyone involved in the project, whose dedication and skill have made this progress possible.
With a length of 64 kilometres, the Brenner Base Tunnel will be the longest railway tunnel in the world once completed. It will shift millions of tonnes of goods from road to rail, relieve pressure on sensitive Alpine regions and make Austria and Italy pioneers in sustainable European transport policy".
The exploratory tunnel: data and historical overview
The exploratory tunnel follows the course of the two main east and west tunnels of the BBT and is located approximately 12 metres below them. It is 55 km long and has two main functions. During the construction phase, it provides information about the rock quality and explores the geological conditions for the subsequent excavation of the main tunnels.
Once the base tunnel is in operation, the exploratory tunnel will be used for drainage and maintenance of the facilities.
Three of the nine TBMs used in the BBT project (Clio, Günther and Serena) were deployed in the exploratory tunnel and excavated a total of around 42 kilometres. The remaining kilometres were or are being excavated using conventional mining methods.
The exploratory tunnel has a total length of 57.5 kilometres, 27.2 of which are in Italy and 30.3 in Austria.
HISTORICAL OVERVIEW:
28.04.2008 Start-up ceremony for the Aica exploratory tunnel (Italy): 10,5 km, Double-shield TBM (diametre 6,3 m)
04.12.2009 start of excavation work in Austria: Sill gorge exploratory tunnel: 5.4 km, excavation cross-section 26 m², excavated using drilling and blasting
03.11.2010 Breakthrough in the Aica-Mules stretch of the exploratory tunnel (Italy)
11.12.2013 Completion of the Sill gorge stretch of the exploratory tunnel (Austria)
26.09.2015 Start of TBM excavation in the Ahrental-Pfons stretch of the exploratory tunnel (Austria) 17 km, open-shield TBM with a total length of 200 metres (diameter 8 metres)
05.01.2016 Start of excavation work in the Wolf stretch of the exploratory tunnel
29.03.2019 Start of excavation work on the “southern” stretch of the exploratory tunnel from Wolf to Brenner
06.07.2020 breakthrough in the exploratory tunnel in the town of Steinach am Brenner
24.11.2021 After 3.5 years and about 14.2 km of excavation northwards by TBM „Serena“, the first tunnel in the BBT project to reach the state border at Brenner was the exploratory tunnel, 1,450 metres below the surface.
18.09.2025 With the completion of blasting excavation in the exploratory tunnel towards the south, for the first time ever, a BBT tunnel tube now connects Italy and Austria.
In May 1994, a railway bypass was opened south of Innsbruck, known as the Inn valley tunnel. This 12.7 km tunnel links to the Brenner Base Tunnel. Passenger and freight trains along this stretch will therefore not only travel through the Brenner Base Tunnel, but for a few kilometres, through the Inn valley tunnel as well. This line, totalling 64 kilometres, will become the longest underground railway connection in the world.
The Brenner Base Tunnel will offer an attractive alternative for freight transport, and for passenger trains, it will open up a completely new way to travel.
Project progress
The Brenner Base Tunnel is actually a tunnel system with a total length of about 230 km of tunnels. So far, 204 km of tunnels have been excavated.
100 km - main tunnel
57 km - exploratory tunnel
47 km - other tunnels
The artwork
It is a symbolic representation of the 64-km long Brenner Base Tunnel - the longest underground railway tunnel in the world.
What you see here are:
- 64 steel rings, each of which is 1 metre long and 80 cm in diameter
- 64 concrete slabs measuring 80×80 cm and made of the recycled spoil from the tunnel
- 32 slabs are made of the rock from the Italian side of the Brenner
- 32 slabs are made of the rock from the Austrian side
- 2 stone-covered external rings, one made from Austrian stone, one from Italian stone
The number of the rings and slabs is meant to represent the 64-km long tunnel and the 8-metre diameter shows the actual cross-section of the tunnel, which is in fact 8 metres.
The work is made up of two halves of equal size that come together as one, representing cross-border cooperation and the union of Europe. It stands for progress, innovation and solidarity. As a striking visual symbol, it clearly shows the meaning of the Brenner Base Tunnel as one of the biggest and most important infrastructure projects in Europe.
Idea and design: Carl Felder
Execution (Model scale 1:10): Carl Felder, Gerald Moroder
