Norway has long been known for its stunning natural beauty and rugged coastline. Now Norway is building an undersea road tunnel, Rogfast, which is expected to become the longest and deepest undersea road tunnel in the world when completed.According to media reports,The Rogfast undersea tunnel under construction in Norway is about 27 kilometers long and has a maximum depth of about 392 meters below sea level. It consists of two independent channels, each with two-way lanes.Its most eye-catching design is a double-decker roundabout that will be built in the middle section at a depth of 260 meters below the sea surface.
Once completed, the tunnel will replace the current ferry and shorten the journey between Bergen, Norway's second largest city, and Stavanger, Norway's fourth largest city, by about 40 minutes, significantly improving transportation efficiency on the west coast of Norway.
Currently, the project has been excavated to 300 meters below sea level. During the construction process, many seawater leaks have occurred in the tunnel, and the staff are evaluating and looking for the best solution to ensure that subsequent projects can be advanced in a safe and efficient environment.
Construction of the Rogfast Tunnel project started in January 2018. It was suspended in 2019 due to cost overruns and resumed construction in 2021.It is currently planned to be completed in 2033, with an estimated total cost of approximately 25 billion Norwegian kroner (approximately 17.5 billion yuan).
For comparison, the current longest tunnel in the world with a submarine section is the Seikan Tunnel in Japan, with a total length of more than 53 kilometers, of which the submarine section is about 23.3 kilometers long and the maximum depth is 240 meters below sea level.
