The overview study for crossing the Stjørnfjord is available
The consulting company Rambøll has now completed the overview study for crossing the Stjørnfjord, which for Fosenbrua AS is a very important step forward. The study has been sent to the respective municipalities as a basis for meetings with Fosenbrua AS on further follow-up.
As is known, the bottom conditions and the mountain course in the Stjørnfjord were mapped with acoustics / light seismic in the summer of 2018, and with a requirement for minimum mountain coverage of 50 meters, an underwater tunnel would have to fall to around 300 m below the sea (muh). Compared to other submarine tunnels, this is relatively deep. The world’s deepest subsea tunnel today is Fv.653 Eiksund tunnel between Volda and Hareid at -287 m, while Rv.13 Ryfast connection between Stavanger and Ryfylke will be the deepest with -291m when it opens in 2019.
Fv. 714 Heat tunnel -264m
Fv. 714 Frøya tunnel -164m
With a depth of 300 meters, Rambøll’s review shows that it will have a length of about 14 km to satisfy the current requirement of a maximum increase of 5%. The traffic analyzes carried out indicate that the connection will have a traffic of over 2,600 vehicles in average daily traffic (ATT) already at the opening, and 3200 bits. AED with new road between Fevåg and Rissa.
The requirements for submarine tunnels have intensified in recent years. Traffic numbers and length means that it will probably be required that it be built in two races or with its own evacuation tunnel. This will have a great impact on the costs of the tunnel solution. The study outlines several possibilities for crossing with bridges, look at the study at Rambøll above to look more closely at the solutions.
For all the solutions, connections to existing road networks are shown. Various conflicts with local communities and the environment are discussed at a relatively rough level, and cost assessments have been made for all outlined solutions.
The costs for the crossing are assessed at between NOK 2.1 and 3.3 billion, including building costs and VAT. As for the tunnel, the costs are based on one race. The cost of new road between Fevåg and Rissa is assessed at NOK 0.9 billion to NOK 1.1 billion, depending on the solution for the fjord crossing.
We believe the overview study provides a good basis for further work on the connection. The traffic analyzes indicate that connection will inflict insignificant traffic on the ferry connection Flakk-Rørvik. As for Fosen, this means that Bjugn, Indre Fosen, Åfjord and Ørland will form a large common housing and labor market, which will have a great impact on further development at Fosen.
CEO Fosenbrua AS
Mobile: +47 952 19 459