The work of the tunnel boring machines (TBMs) in the Brenner Base Tunnel is much more than an extraordinary engineering challenge: it is an epic journey into the heart of the Alps. TBM Flavia, for example, is working under a massive overburden of over 1,200 metres and is facing some very challenging conditions as it advances along the route.
However, her task is not limited to excavation work: like her sister machine Virginia, which completed her journey in the eastern main tunnel on March 30th, 2023, Flavia also fulfills another fundamental function.
As it advances, she installs tubbing rings - precast concrete elements - which form the tunnel's final lining, ensuring the infrastructure's stability and safety.
Towards Brenner: last kilometre for the western main tunnel
The tubbing rings installed by TBM Flavia come from the plant in Hinterrigger, where the production of precast concrete elements for the Brenner Base Tunnel ended on September 19th, 2024.
In just under seven years, slightly more than 218,000 tubbing rings have been produced using an eco-friendly process that involves the reuse of approximately 30% of the excavated material.
“We are about to excavate the last kilometre for TBM Flavia; once completed, all excavation works on the line tunnels at the Mules construction site will be finished,” explained Alessandro Marottoli, Director of Proceedings for the Mules 2-3 construction lot.
In addition to TBM Flavia, four other TBMs are in operation in the BBT project: Ida (on the H41 Sill Gorge-Pfons construction site, in the western main tunnel moving southwards), Lilia (on the same construction site but moving southwards, in the eastern main tunnel), Wilma and Olga (on the H53 Pfons-Brenner construction site moving northwards, in the western and eastern main tunnels respectively).
