The Brenner Base Tunnel is divided into 4 lots:
- Gola del Sill
- Mules 2-3
General information about the Mules 2-3 lot
As part of the "Periadriatic Line" construction lot, in the period between October 2011 and July 2015, 3.7 km of the main tunnels and 1.5 km of the exploratory tunnel were excavated on Periadriatic Line, one of the areas of the most significant faults in the Alps. With the conclusion of this lot, the logistical conditions were created to tackle the next lot called "Mules 2-3".
This lot was started in September 2016 and is the largest in the Brenner Base Tunnel. Lot Mules 2-3 was awarded for 993 million euros to the grouping consisting of Astaldi S.p.A., Ghella S.p.A., Oberosler Cav Pietro S.r.l. (until June 2018), Cogeis S.p.A. and PAC S.p.A.
"Mules 2-3" extends from the construction lot of the "Underpass Isarco" to the south to the state border. Over the course of 7 years, 39.8 km of line tunnels and 14.8 km of exploratory tunnel will be excavated, the Trens emergency stop with its access tunnel, and the cross tunnels, which will connect the main pipes every 333 meters. . By the end of 2023, 65 kilometers of tunnels will therefore be excavated within this single lot. Once "Mules 2-3" is finished, all the excavation works in Italy will be completed.
On 11/24/2021, after 14 kilometers and 3.5 years of excavation, in the exploratory tunnel to the north, the "Serena" mechanical milling machine reached the finish line at the state border. It is the first time that the excavation of the pipes of the BBT tunnel reaches the Brenner, and this represents a historical event.
Trens emergency stop
The excavation works for the construction of the connection of the Mules access tunnel with the future emergency stop of Trens began in December 2016 and ended in June 2020. The tunnel is 3.8 km long, with an excavation section of approx. . 80 m2.
From 13 March 2017 the excavation works of the main pipes have restarted towards the north. After about 0.8 km, the excavation section using the traditional method was completed and excavation began with the mechanized method using two TBMs. The latter will dig up to the state border.
To the south, the traditional excavation started on 3 April 2017. The excavation works for the line tunnels ended in October 2020.