Tunnelling progresses on Oslo water project

13 September 2023

A TBM that will drill one of the tunnels for the Oslo New Water Supply Project has arrived in the Norwegian capital.

The Herrenknecht machine was manufactured in Germany, and the largest and heaviest parts were transported by ship to Norway. At Ormsundkaia, they were loaded onto trailers and transported to the construction site at Stubberud.

The TBM will now be assembled in a mountain hall before AF Ghella JV launches it to bore an 11km-long tunnel from Stubberud to Huseby. When fully assembled, the machine is 200m long and weighs around 2000 tons, and has a diameter of just over 7m. 

The AF Ghella JV is responsible for building the tunnel system for the distribution of drinking water from the water treatment plant at Huseby. The E6 contract also includes the construction of four large rock caverns, two clean water basins, a pumping station and a ventilation station. 

In April, Skanska Norway, which has the E5 contract, launched two 5.2m diameter Herrenknecht TBMs to dig the 19km tunnel from Holsfjord to the new underground water treatment plant at Huseby.

The NOK26.8bn (€2.34bn/US$2.51bn) water project is a major undertaking by the City of Oslo Municipality to provide water supply security through a new clean water tunnel from Holsfjord, west of the capital, and an underground treatment plant at Huseby. At present, a single water source and one treatment plant supply around 90% of the capital.