The TBM, which in Italian is called a “talpa”, or a ‘mole’, can move in the proper direction thanks to the valuable information provided to it by our topographers, who use lasers to show it which way to dig.
“The laser beam, which is red for TBM guidance systems, indicates the direction to follow. In the deep tunnels of the BBT, satellite GPS doesn’t work and of course there’s no way to look at the stars to figure out where you are and where you’re going. In the darkness of our tunnels, we follow the lasers’ red light,' explains Simone Cappelletto, Head of Topography and Structural Monitoring for the Italian side of the Brenner Base Tunnel.
At the helm of the TBM is an experienced operator who sits in a booth that looks a lot like an airplane cockpit; thanks to a large number of sensors, he is able to monitor everything that the machine is doing and how. The data from these sensors are collected and processed by the on-board computers of the TBM.
TBM Flavia is about 1.6 km from the Brenner Pass
This topography work is very important: it allows the TBM to keep moving in the right direction.
Simone Cappelletto, who supervised all three TBMs at the Mules site, says of Flavia: “Flavia is about 1.6 kilometres from the Brenner Pass now and along with the excellent team of technicians who assist her every day, the laser is her most valuable ally.”
Flavia, a TBM whose cutter head diameter is 10.71 metres and is approximately 200 metres in length, set off on 16 April 2019 from the west logistics chamber of the ‘H61 Mules 2-3’ construction site. She has travelled approximately 12.7 kilometres to date.
Once Flavia has also reached her destination, all three Italian TBMs will have reached the Brenner Pass: Serena arrived in November 2019 after excavating the exploratory tunnel, while Virginia completed her journey through the east line tunnel in March 2023.
The TBMs never saw the light of day, during their journey through the heart of the mountain. That’s because they were assembled inside the tunnel itself, in special assembly chambers, and two of them, Serena and Virginia, were dismantled once they arrived at the Brenner Pass. The same will happen to Flavia, which will be dismantled after it reaches the Brenner Pass over the course of next year.
