The borers chosen to dig the four base tunnel ventilation shafts represent a solution able to maximize the safety of workers compared to traditional drilling methods; they also reduce the impact on the territory, thanks to the limited extent of the excavations. Seven caverns, each up to 22 metres high and 23 metres wide, will also be dug during the work. They will be used for the assembly of the borers that will excavate the base tunnel towards Italy. The excavated material will be transported to the exterior using the existing winze. The contract, worth about 220 million euros, has been awarded to the grouping of companies composed of VINCI Construction Grands Projets, Dodin Campenon Bernard, VINCI Construction France, Webuild and Bergteamet.