Brenner Base Tunnel Connects Austria Italy Both Main Tubes

INNSBRUCK, Austria – Miners and project managers crossed the Austria–Italy border through both main tubes of the Brenner Base Tunnel for the first time on 28 July, following a simultaneous breakthrough at the H53 Pfons–Brenner section. The 64 km railway tunnel, running about 1,400 metres beneath the Brenner Pass, is scheduled to carry freight and passenger trains by around 2032.

What Is the Full Scope of This Project?

The Brenner Base Tunnel is a 64 km rail link between Innsbruck, Austria, and Fortezza, Italy, designed to remove the Brenner Pass bottleneck on the Scandinavian–Mediterranean TEN-T corridor. The project includes two main single-track tubes, a separate exploratory tunnel, and connection shafts to the existing rail networks at both ends.

As of the July 2025 breakthrough, Austria and Italy were linked through three tunnels: the two main tubes plus the exploratory tunnel that broke through in September 2025. Nearly 90 km of rock had already been excavated, with the remaining TBM drives by machines Wilma and Olga expected to finish around mid-2026.

Key Project Data

How Does This Compare to Similar Projects?

The 64 km Brenner Base Tunnel will surpass the 57 km Gotthard Base Tunnel, which opened in 2016 and cost approximately CHF 12.2 billion, as the longest railway tunnel in the world (Source: SBB, 2016). The twin-tube layout matches Gotthard’s design, but BBT adds a separate exploratory tunnel, increasing the total rock excavation to nearly 90 km of galleries and tubes (Source: Construction Review Online, 2025).

In cost terms, the $11.5 billion BBT budget is broadly comparable to Gotthard’s final account, while its construction timeline from initial works to the 2032 opening target extends to roughly 27 years versus Gotthard’s 17 years. The exact share of the overall tunnelling programme completed as of the July 2025 breakthrough was not disclosed by BBT SE.

Editor’s Analysis

The breakthrough narrows the open technical risk in Europe’s most complex cross-border tunnel project, shifting the critical path from rock excavation to rail systems installation. For Austria’s freight market, where Rail Cargo Austria’s share fell from 57.3% in 2024 to 52% in 2025 and non-incumbent operators now hold more than 60% on main transit corridors, BBT capacity will increase competitive pressure and support the modal shift underpinning Europe’s projected 4.2% annual rail freight revenue growth (Source: IBISWorld, 2025; railmarket.com, 2025).

FAQ

Q: How long is the Brenner Base Tunnel and how does it compare with the current record holder?
A: The Brenner Base Tunnel will be 64 km, making it longer than the 57 km Gotthard Base Tunnel in Switzerland. It runs about 1,400 metres beneath the Brenner Pass between Austria and Italy.

Q: When will trains run through the Brenner Base Tunnel and what remains unfinished?
A: Passenger and freight service is planned for around 2032. The main tube excavation is expected to be complete by mid-2026, after tunnel boring machines Wilma and Olga finish the remaining sections near Innsbruck.

Q: What did the July 2025 breakthrough achieve technically?
A: It connected Austria’s conventionally excavated main tubes with Italy’s tunnel-boring-machine-driven main tubes, with survey deviations of only a few centimetres. Because the exploratory tunnel was already linked in September 2025, the two countries are now connected through three tunnels of the BBT system.