Tunnelling Completed on Italian Brenner Base Tunnel with Herrenknecht TBMs
A major milestone has been achieved in one of Europe’s most significant transport infrastructure projects, with the completion of tunnelling on the Italian side of the Brenner Base Tunnel.
The final breakthrough was made as the last of three Herrenknecht tunnel boring machines (TBMs) completed its journey beneath the Italian-Austrian border from the south. This marks the end of excavation for construction lot H61 Mauls.
The Brenner Base Tunnel, overseen by Austrian-Italian joint venture BBT SE, will span 64 kilometers between Innsbruck (Austria) and Franzensfeste (Italy), making it the world’s longest underground railway connection. It forms a central part of the trans-European north-south corridor from Finland to Malta and is designed as a flat, high-performance railway line with minimal gradients to enhance freight and passenger rail efficiency.
On the Italian side, a joint venture led by Webuild, Ghella, P.A.C., and Cogeis used two Double Shield TBMs (10.65 m diameter) to excavate 14.3 kilometers of the main tubes, successfully navigating high-strength rock and complex fault zones. A third TBM (6.8 m diameter) completed a parallel service and rescue tunnel beneath the main tubes.
Meanwhile, on the Austrian side, four Herrenknecht TBMs are currently progressing on the main tubes. The Austrian section of the service and rescue tunnel was completed back in 2020 using a similar machine.
Herrenknecht has supplied a total of eight TBMs for the Brenner Base Tunnel, which is a cornerstone project for sustainable rail infrastructure in Europe.
