White Papers

The Return of TBMs to Norway at Røssåga HEPP—TBM Operation Through Extremely Hard Rock, Unstable Rock Mass, and Other Challenges

The TBM that broke though at Røssåga HEPP in December 2015 was the first to breakthrough in Norway in more than 20 years. During the excavation the TBM encountered extremely hard rock (over 280 MPa), which posed an extreme challenge for both the TBM and the cutters. During the excavation a highly efficient main bearing replacement was also performed in the tunnel. This paper discusses the project as a whole, including TBM design, Onsite First Time Assembly (OFTA) of the machine, challenges faced, and project outcomes.


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