Less than a year after the previous open day organised at the entrance to the base tunnel on the French side, TELT once again welcomed the public on the 14 and 15 June 2025, this time at the Saint-Martin-la-Porte construction site. 

Together with the TELT teams, the companies working on the CO7 construction site – VINCI Construction, Dodin Campenon Bernard and Webuild – welcomed numerous French and Italian visitors who came to discover what goes on behind the scenes at the construction site. 

This new edition allowed the public to descend into the heart of the mountain to get a closer look at Viviana, the first of seven new TBMs that will continue the excavation of the base tunnel, and to learn about the methods, techniques and equipment used. 

A specific tour route on the outdoor platform also provided a better understanding of water and excavated material management at the site. 

For further information click here, fr/11 and it/80 for tunnelbuilder archive. Visit https://www.telt.eu/. 25/25.