First TBM breakthrough of a main tunnel tube in Austria

A significant moment for the cross -border railway infrastructure project Brenner Basist tunnel: After around 26 months of uninterrupted work, the tunnel boring machine (TBM) “Ida” successfully completed the first breakthrough of the main tunnel tube on the Austrian project page. The breakthrough point is located in the area of ​​the municipality of Navis (Wipptal) in an existing assistance attack “Iris”, which borders on the “H53 Pfons burner”. In modern tunnel construction, the auxiliary attack represents an important supplementary measure to support the main tunneling and to secure the relevant tunnel section in advance.

Since the start in June 2023, “Ida”, a tunnel boring machine, which weighs around 160 meters long and 2,450 tons, has milled with a drilling head diameter of 10.4 meters, a total of 8,400 meters of mountains in the buildingless “H41 Sillschlucht-Pfon”. The propulsion was based on the Ahrental project section near Innsbruck in the western main tunnel tube towards the south and led partly through geologically extremely demanding zones.

Martin Gradnitzer and Gilberto Cardola, board members of the BBT SEit is pleased: “After the arrival of the last Italian TBM on the state border on the Brenner a few months ago, Ida’s breakthrough now marks another central project success on the Austrian side.”

Special technical hurdles represented several complex geological disruptive zones – in particular the well -known zones “Viggartal”, “Walzn” and the approximately 35 meter -powerful zone “Werner”, which was carried out without any problems at the beginning of 2025.

Judith Engel, Machine Prison of “Ida”, BBT supervisory board and board director of the ÖBB-Infrastructure AG: “Another step for one of the most important traffic axes in Europe is successfully set with the arrival. We congratulate the project team on the excellent work. With the Brenner base tunnel and its inlet routes, we create a reliable and future -oriented infrastructure for future generations.”

“Ida”: A name with meaning
The TBM was baptized in 2023 by children from the Navis elementary school in the name “Ida” – named after a calf on the farm one of the students. The name symbolically stands for diligence and activity. The children accompanied “their Ida” over the entire project time. Finally, they were even allowed to design one of the last Tübbinge – ready for concrete for the lining of the tunnel wall.

A look ahead: Arrival TBM “Lilia” planned in autumn
In autumn 2025, the breakthrough of Ida’s twin sister, the TBM “Lilia”, is expected in the eastern main tunnel tube. This would complete all machine propulsion work in the “H41 Sillschlucht-Pfon” section-another big step on the way to completion the Brenner base tunnel.

The tunneling work towards the south continues
The main focus is now on the exploration tunnel. On September 18, 2025, the first cross -border underground connection between Italy and Austria is celebrated: a historic milestone for European mobility.