Two of the TMBs (tunnel boring machines) with which AGJV (Acciona and Ghella Joint Venture) is drilling Follo Line’s high-speed rail tunnels between Oslo and Ski have reached the Norwegian capital.
The AGJV consortium is using four dual-shield TMBs to build twin 19.5-kilometre tunnels, each with an interior diameter of 8.8 metres. The four machines departed from the same point, the Norwegian town of Asland, with two of them drilling south toward Ski and the other two northbound toward Oslo.
The Asland-Oslo segment whose drilling is finished is 9 kilometres long and has taken two years. Drilling is scheduled for completion in spring 2019, when the last two TBMs reach the surface in Ski. The project is approximately 65% complete at present and is scheduled for completion in December 2021.