The official TBM launch ceremony took place in February 2016 and marked the start of the construction of the 3.2 km long Belchen rehabilitation tunnel. ILF Consulting Engineers has been entrusted with the construction supervision of the tunnel and, together with partners, also with its design.
With a diameter of 14 m, a length of 75 m and a weight of 2,000 tons, the TBM is currently the largest of its kind in Switzerland. In the next one and half years, the TBM will advance through geologically demanding zones of the Swiss Jura mountain range and will be driven through the mountain at distance of 40-116 m to the existing tunnel system and parallel to it. Subsequently the final lining is also to be constructed.
At the end of the construction works in 2022 the two existing tubes of the Belchen tunnel dating from the 1970s are to be rehabilitated as well.