World's longest undersea tunnel stretching 17 miles and costing £1.8bn gets major update

World's longest undersea tunnel stretching 17 miles and costing £1.8bn gets major update The Rogfast tunnel in Norway is set to become the world's longest and deepest underwater tunnel when it is completed in 2033 - and it has just received a major update The Rogfast Tunnel in Norway is set to be a truly incredible feat of engineering. Not only will it be the world's deepest undersea tunnel, plunging 400m beneath the surface, but it will also be the longest, stretching an impressive 27km (roughly 17 miles). Now a significant development has emerged in the extraordinary scheme to keep the project on track. Work on the ambitious scheme, which will link the villages of Randaberg and Bokn, initially began in January 2018 but was suspended the next year amid soaring costs. Construction restarted in 2021 following revised plans, and now a significant development has been confirmed which will give the project a major boost. The remarkable tunnel forms part of a broader upgrade of the E39 road, a coastal route linking Trondheim and Kristiansand in Norway. At present, journeying between these two locations takes 21 hours and requires multiple ferry crossings. The long-term goal is to replace all seven ferry crossings with tunnels and bridges, which would cut the 21-hour journey down to 11 hours. Authorities are aiming to complete the entire project by 2050. This first tunnel will shave 40 minutes off the trip between Stavanger and Bergen while boosting transport reliability. Earlier this month the Nordic Investment Bank (NIB) approved a NOK 4 billion loan (approximately £307m) to fund the scheme, with Norwegian toll operator Ferde AS serving as an intermediary, reports the Express. "Reliable infrastructure is essential for regional development and efficient transport links. Rogfast will improve connectivity in wester Norway and support the long-term integration of labour and transport markets," said Carlos Rodriguez, senior bank at NIB. The overall cost is anticipated to reach NOK 25 billion (approximately £1.8billion), with around 4,000 vehicles expected to pass through each day. The Rogfast Tunnel, also referred to as the Boknafjord Tunnel, will even feature a double roundabout deep beneath the sea, connecting to the island of Kvitsøy - and travellers will find themselves descending further underground than the height of the Empire State Building. Construction giant Skanska, which is overseeing the northern section of the tunnel, has spoken openly about the challenges involved in drilling so far beneath the ocean. Project manager Anne Brit Moen told Engineers Ireland: "Since we are going all the way down to 392m below sea level, we're focusing on finding the best methods to maintain safe and efficient working conditions for everyone. The tunnel will significantly improve connectivity along the Norwegian west coast." Norwegian Public Roads Administration project manager Oddvar Kaarmo added: "About half a year after the last drill and blast, we have to deliver the project, so we have to get a lot of work done simultaneously. It's more about logistics than tunnelling," as reported by the Daily Telegraph. An art installation will be placed inside the tunnel to "prevent monotony" and "alleviate tunnel anxiety", with those overseeing construction hopeful that this measure will reduce the number of accidents.