Drill & blast tunnel breakthroughs come frequently in Norway, on numerous road tunnel projects through hard rock.
The road tunnels can be after fairly short but more often longer drives to create large profiles – sometimes for single tunnels that will take bi-directional traffic in more remote parts of the mountainous country, but moreso and increasingly for twin tubes in many areas, either more populous or on strategic routes.
One of the longer projects, twin-tunnel projects underway is Rogfast, in south-west Norway. It will be the world’s longest subsea road tunnel. Blasting is progressing but there is still a long way to go. And, many more tunnels are being excavated, elsewhere.
More recent celebrations of breakthroughs come from other road projects, such as Fåberg Tunnel, on the E6 motorway near Lillehammer, north of Oslo; and, the Grenland Tunnel on the E18, south-west of the capital.
So experienced is the country in rock tunnelling for roads, in fact, that as such a ‘knowledgeable client’ the national roads authority (Statens Vegvesen – NPRA) late last year agreed to help another agency on an uncommon, but vast tunnel project.
The Norwegian Coastal Administration (Kystverket – NCA) is building a colossal, one-off tunnel through a mountain for full-sized ships to pass through and so bypass often difficult waters. After years of planning, and supported by the roads authority, the coastal agency now has procurement well advanced for the huge drill & blast project.
SHIP TUNNEL
Challenges are many for large ships to safely negotiate the, at times, waters off the rugged, fjordic west coast of Norway.
A known tough spot of ships is the Stad peninsula, where ships move round that jutting headland, but there is a huge tunnelling project planned to help them skip that problem.
In future, the full-size ships are to sail through the mountainous peninsula – passing along a large tunnel, from one fjord to the other. The ships can bypass the headland and the potentially difficult waters.
They will sail, slowly, through a vast, cathedral-like tunnel, entering at one portal and progressing onward, to emerge from the other. One ship at a time, through the 1.7km-long tunnel.
The solution to the shipping problem calls for design and construction of what is, in effect, a colossal cavern open to the air at both ends. In shipping, and tunnelling, it is a highly uncommon type of project. Also, it is a major challenge in drill & blast works.
The owner-developer is the NCA, which has been progressing plans for the project for some years. But it is not a tunnel builder, with such experience inhouse for managing the creation of such a major piece of infrastructure. Last year, therefore, a strategic move was made to bring onboard the well-proven and longestablished skills in tunnel building and management of another national agency – the roads authority.
Statens Vegvesen has numerous tunnel projects of its own under development and construction, but has been able to support this unusual endeavour to build the Stad Ship Tunnel.
When signing the collaboration , NCA directorgeneral Einar Vik Arset, said in a statement: “The NCA is considered a one-time constructor when it comes to such a large project as the Stad Ship Tunnel, so it is not ideal to build a large internal project organisation; that is why we have initiated a collaboration with the Norwegian Public Roads Administration. This will give the NCA access to expertise and capacity from an experienced project management organisation, thereby strengthening our own project organisation.”
Among the resources NCA would see brought in to work on the Stad Ship Tunnel have been project and construction management, geology, tunnel operations, health and safety, and workplace regulations, to prepare the project organisation for construction.
Statens Vegvesen’s division director, Kjell Inge Davik, at the collaboration signing, described the ship tunnel as “a spectacular and incredibly exciting project,” and noted there was major interest from everywhere, including the construction industry.
He added: “We have broad expertise in large infrastructure and tunnel projects, which will benefit the ship tunnel, both in the upcoming tender and contract phase, and potentially in the construction phase.”
The agreement primarily governs the procurement phase and leading up to contract signing. But the collaboration may be extended to cover the construction phase.
Recently, it was announced that three prequalified bidders had submitted first offers in the procurement process. They are: a joint venture of Skanska Norge AS and Vassbakk & Stol AS (Norway); AF Gruppen Norge AS (Norway); and, Eiffage Génie Civil (France).
NCA hopes to sign the contract in autumn this year and for construction to start in 2026.
RECENT ROAD TUNNEL BREAKTHROUGHS Fåberg Tunnel
AF Gruppen is building the 2.8km-long twin-tube Fåberg Tunnel on the E6 motorway, north of Oslo, for client Nye Veier.
The tunnel is part of Nye Veier’s new E6 section of road, being built and operated, between Storhove and Øyer in Innlandet, near Lillehammer. The E6 is seen as one of the main road arteries for transport through the country.
The contractor started in January 2024 and achieved breakthrough on the tunnelling works early this year. More than 1,200 blasts were carried out for the two tubes since work began and more than 450,000m3 of rock was removed.
Hard rock, though, does not mean tunnelling is straightforward, of course. The project has encountered challenging rock quality, with occasionally demanding geological conditions and need for extensive safety work.
Following the completion of drill and blast work, construction has moved to lining the tunnels, including water- and frost-proofing, and also the drainage and road surfacing, to be followed then by M&E, lighting and signage fit-out.
The new section of E6 between Storhove and Øyer is one of three parts of the larger development of the E6 through Innlandet.
Nye Veier and AF Gruppen are working on a neighbouring section, from Storhove south to Roterud.
Grenland Tunnel
Late last year, contractors Eiffage Génie Civil and Metrostav Norge achieved breakthrough on the northern section of the Grenland Tunnel on the E18 motorway.
The breakthrough marked the end of excavation for the twin 5.1km-long tunnel, on Lot 2 of the Langangen- Rugtvedt project.
The Langangen-Rugtvedt project is in the south of Norway and will provide a bypass around the city of Porsgrunn, on the E18 motoway between Oslo and Kristiansand. The project is being developed by the Ministry of Transport.
The section of E18 is 17km-long and construction includes a four-lane highway, bridges, and tunnels. The works are being executed in lots.
Eiffage also has the design and build contracts for Lot 1 (Langangen-Lanner) and Lot 3 (Kjørholt-Rugtvedt). Lots 1 and 3 works are expected to be delivered mid- 2025; Lot 2 is scheduled for completion by early 2026.
