In February 2025, excavation work began on the construction of the second tube of the Gotthard motorway tunnel. While the TBM on the north side is progressing steadily, on 23 June 2025 it was necessary to stop the TBM on the south side after about 190 m, as analysis revealed critical issues in the next 500 m: a partially unstable rock mass with obvious fractures and cavities. 

The Federal Roads Office (FEDRO) therefore conducted in-depth geognostic survey in the affected area and, in consultation with engineers, geologists and the contractors involved, decided to replace the TBM used to date in this section with traditional blasting techniques. An access tunnel will also be constructed, from which work will be carried out simultaneously in advance of the stationary TBM and for approximately 300 m in the direction of Goeschenen. 

The additional costs amount to EUR 16-21 million/CHF15-20 million (total project costs: EUR 2.30 billion/CHF 2.14 billion) and the expected duration of the work is six to eight months. The remaining work on the north and south sides is continuing according to plan. Despite the unexpected additional costs, the Federal Roads Office (FEDRO) currently expects to meet the announced opening date (2030) for the second tunnel and the total estimated costs.

To ensure that the schedule is adhered to, various measures will be taken, including bringing forward crucial work to meet the deadlines. Excavation work using conventional methods will be carried out 24 hours a day, with continuous shifts and three shifts of operational personnel.

 For further information please click here and ch/50 for the tunnelbuilder archive. Visit  https://gotthardtunnel.ch. 28/25.