Tunnel breakthrough at Bergåstunnel on 7 February 2024. Watch the last volley go off (multiple camera angles, normal and slow motion):

Statens vegvesen says;

Only half a year late, the contractor and developer were able to celebrate success in the Bergåstunnel. 70 meters of loose material did not stop the tunnel specialist from Andøy.

Last year, LNS AS became the first contractor to operate a large bulk tunnel in Norway without expert help from abroad. On Wednesday this week, the company and their employees could celebrate the very last salvo in the 2,020 meter long tunnel.

- Our skilled workers have been on site since day one and operated safely and efficiently from the first salvo in September 2022 until now. The unforeseen loose mass zone caused delays, but after we got through the zone, operations have been good and progress has been expected. This is a big day for the project as a whole and now we end the tunnel section with a bang. All credit to our clerks and skilled workers for the effort they have put in. That's what plant manager Helle Ragnete Fyhn Nilsen at LNS AS says.

A mountain of challenges
In the south, the new Bergåstunnel sneaks directly under the Nordlandsbanen with a few meters of cover. Good rock for the first 600 meters gave very good progress. Then came 70 meters of loose masses and weathered rock that required heavy protection and very careful driving. From then on, the drive went smoothly. If one disregards start-up and loose mass driving, the average production has been approximately 55.3 meters of tunnel per week. In November 2022, a weekly record was set with 73 meters of drift.

- This has been a very instructive project for LNS and the collaboration between our officials, the client, the National Road Administration, and the suppliers has been extremely good. Open and honest communication combined with correct handling of challenges and deviations are some of the experiences we will take with us further in other projects, says Fyhn Nilsen.

The Bergåstunnel has given LNS as general contractor and the Norwegian Public Roads Administration as client some solid challenges. This has been tackled in an exemplary manner by LNS and their partners in the project. The learning effect from Bergåsen will also benefit the Norwegian tunneling industry in the future, for example through experience sharing and the participants bringing their experiences to new projects.

- The way LNS has mastered this challenge makes it easy for us to say that we are more than happy to collaborate with them on a later occasion. That's what project manager for E6 Helgeland, Bård Nyland, says at Statens vegvesen (the Norwegian Public Roads Administration).

Further work in the tunnel now remains, including water and frost protection. The new E6 Svenningelv-Lien is planned to open late in 2025.

Facts about the Bergås tunnel
Total length: 2020 meters (+ two transverse sections of approx. 30 meters for the technical room)
Length of loose masses: 70 metres
Amount of steel for securing the bulk part: 40713 kg rebar
Number of securing bolts in the rest of the tunnel: approx. 11500 (both securing bolts, bomb bolts and play bolts)
Cubic meters of blasted rock: slightly over 162,000 m3. (quantity for the last week is added)
Number of salves: approx. 379 clean volleys in the Bergåstunnel including cross blows
Other quantities: 6685 m3 of concrete and 28 arches (excluding the loose mass zone
Company involved including engineering: LNS AS, Aas Jakobsen and NGI

press release https://kommunikasjon.ntb.no/pressemelding/18047077/gjennomslag-i-losmassetunnelen-pa-helgeland?publisherId=17847490&lang=no