FINAL METRES FOR WILMA: THE AUSTRIAN TBM PREPARES TO REACH THE FINISH LINE
Following the breakthrough between Italy and Austria on July 28th, the next milestone is already just around the corner: the TBM Wilma is on the home stretch and is excavating the final metres of the west main tube.
Since the breakthrough at the state border, only a few kilometres of tunnel excavation remain until the completion of the two future railway tubes: two short tunnel sections in the H53 Pfons-Brenner construction lot, where the tunnel boring machines Wilma and Olga are currently working.
In Wilma's case, we are truly in the final stretch. Only about 100 meters lie ahead of the machine. After that, it will reach her destination at the border with the neighbouring construction lot H41 Sill Gorge-Pfons - the same lot boundary where the two boring machines Ida and Lilia arrived last year.
In the target area of the TBM, there is a large cavern that enables the most efficient possible dismantling of the TBMs.
TBM Wilma: key facts and figures
Let’s take a closer look at some details about Wilma. Measuring 180 metres in length, the tunnel boring machine features a cutterhead diameter of 10.37 metres and weighs 2.700 tonnes. By the end of her journey, she will have driven just over 7.4 kilometres heading towards Innsbruck along the west main tunnel tube, and that is not all. Throughout this adventurous journey, during which she crossed the Heidi and Jana fault zones, Wilma has already installed approximately 23.000 lining segments, corresponding to over 3.800 rings (each ring consists of six segments). Her progress northbound was therefore not merely an excavation drive, but also a decisive contribution to the final lining and structural stabilisation of the tunnel.
Wilma, a highly determined TBM
Back at the inauguration ceremony on 18 September 2024, Helga Morandell, the TBM's patroness, revealed the reasoning behind the choice of this TBM's name: "Wilma is the feminine form of Wilhelm, and the name Wilhelm derives from 'willio' (will/determination) and 'helm' (protective helmet). In relation to the Brenner Base Tunnel, one can clearly say that the realisation of this 'project of the century' is being driven forward with great determination," Helga told us. Looking at the results of the TBM, which will have successfully completed her route in under two years, stubborn determination was certainly not lacking.
And what's next? Once Wilma has completed her journey, only the tunnel boring machine Olga will still be operating in the east main tube of the Brenner Base Tunnel. There, she is excavating the final kilometres and is expected to reach her destination before the end of this year. With Olga's arrival, the excavation work on the main tunnel tubes of the BBT will be completed.
