Historic Major Breakthrough in the Brenner Base Tunnel Achieved
On 18 September 2025, a historic milestone was reached: with the breakthrough of the exploratory tunnel, the first of the three tubes of the Brenner Base Tunnel was completed. For the first time, air now flows underground from Italy to Austria.
A momentous event for what will become the world’s longest railway tunnel at 64 km, celebrated with more than 1’000 invited guests. The significance of the occasion was reflected in the guest list: in the presence of EU Commissioner Apostolos Tzitzikostas, Italian Prime Minister Giorgia Meloni, Austrian Federal Chancellor Christian Stocker, and numerous other political and industry leaders, the breakthrough of the exploratory tunnel was marked in a festive ceremony.
The two Executive Directors of BBT SE, Gilberto Cardola and Martin Gradnitzer, stated: “With its length of 64 kilometres, the Brenner Base Tunnel will be the world’s longest railway tunnel upon completion. It will shift millions of tons of freight from road to rail, relieve the sensitive Alpine regions, and position Austria and Italy as pioneers of a sustainable European transport policy.”
Amberg Engineering AG is proud to be the lead partner of the design consortium, responsible since 2014 for planning the Austrian section of the tunnel in close cooperation with BBT SE. This includes design planning, permit applications, tendering, and detailed design for the major contracts H21 (Sillschlucht), H41 (Ahrental), and H53 (Pfons-Brenner) between Innsbruck and the Austrian-Italian border.
The overall project comprises around 230 km of tunnels and galleries, including two main tubes and the slightly deeper exploratory tunnel, which will also serve operational purposes. Cross-passages every 330 m and three emergency stops ensure operational safety even in the event of an incident. The tunnel system is also connected underground to the existing Innsbruck bypass via complex junction structures.
Three of the nine TBMs used on the BBT project were deployed in the exploratory tunnel, excavating around 42 km. The remaining sections were excavated by conventional tunnelling methods. The final breakthrough of the two main tunnel tubes is scheduled for 2026, followed by interior works, railway systems installation, and commissioning.
Amberg Engineering AG and all involved employees are proud to contribute to this century-defining project and to help secure its success.
Hearty congratulations to BBT SE on the breakthrough of the exploratory tunnel between Austria and Italy and continued success!
Glück Auf!
