- Project plans
- Project activities
- Legislation and standards
- Industry context
- Specialist wikis
Last edited 30 Nov 2020
Norway could build world-first floating tunnel
The west side of Norway is made up of 1,190 fjords, which, while beautiful, make it very hard to travel along the country’s coastline.
Currently, the drive from the southern city of Kristiansand to Trondheim in the north takes 21 hours and requires seven ferry crossings.
To make that drive easier, the Norwegian Public Roads Administration (NPRA) has proposed the world’s first underwater floating tunnel, which would be submerged in the Norwegian Sea. It is predicted to cost $25bn (around £19m) to build.
The tunnel is part of a series of proposed solutions for the Route E39 coastal highway devised by the NPRA.
 What would it look like?
The floating underwater tunnel would consist of two 1,220m-long concrete tubes, submerged 20m below the surface of the Norwegian Sea.
Although no floating underwater tunnel like this has ever been built before, a British patent for a similar structure dates back around 100 years.
Underwater tunnels could be put in place across the fjords from Kristiansand in the south of Norway to Trondheim in the north.
Image: Google Maps
For motorists underwater, the experience would be similar to being in any other tunnel.
The tunnels would enter the bedrock beneath the fjord on each side.
The submerged tubes would be steadied either by being attached to floating pontoons on the surface of the sea or by cables attached to the sea floor..
There would be wide gaps between the pontoons to allow ferries to pass through.
Another option suggested by the NPRA is to combine an underwater tunnel with a bridge.
This solution is reminiscent of the Øresund which connects the Danish capital of Copenhagen to the Swedish capital of Malmö.
The NPRA is also considering creating a 3,700m-long suspension bridge, which would be three times the length of San Francisco’s Golden Gate bridge and double the current world record for a bridge’s length.
The towers on each end of this world-record-breaking suspension bridge would stand at 450m tall — around 150m taller than the Eiffel Tower.
The first proposed crossing is for Sognefjord which links up Oppedal with Lavik. By 2035, the crossings are set to be installed between many of the country’s fjords, according to Wired.
Sognefjord. (Image: Shutterstock / S-F)
 About this article
This article was written by Will Heilpern, Features Writer, Business Insider, and is published in collaboration with Business Insider. The views expressed in this article are those of the author alone and not of the World Economic Forum. It was also published on the Future of Construction Knowledge Sharing Platform and the WEF Agenda Blog.
 Related articles on Designing Buildings Wiki
- At grade.
- Excavating plant.
- Ground conditions.
- Grouting in civil engineering.
- Railway engineering.
- Road construction.
- Sewer construction.
- Shotcrete technology.
- Temporary works.
- Trench support.
- Trenchless technology.
- Tunnels of the world.
- Underpass construction.
Featured articles and news
What to do with troublesome statues?
A tricky political issue.
Designing Buildings content from and for its users
Discover more on how simple and quick it is to publish an article.
Recent users articles; Timber and retrofit
Which products, for what reasons.
Recent users articles; Digitally Built Britain
ISO 19650, BIM and data management.
Recent users articles; Interim valuations and payments
Applications, notices ad points to remember.
Recent users articles; What is H-Scaffolding?
Elements, features and areas of use.
Recent users articles; what are NZEBs ?
How do they contribute to Sustainable Development.
The most viewed articles in 2022 on Designing Buildings
Written in the past 6 months, one year and beyond.
Second stairs for new tower blocks
Government launches a 12-week consultation
Happy Festive Holidays to all our users from here at DB
On the first day of Christmas DB for the Industry...
The psychological power of the built environment.
IHBC signpost update from Lords Committee on climate
Government must support behaviour change to meet targets.
Reflecting on 2022 into 2023 with the APM WiPM SIG
Women in Project Management conference 2022.
Types, colours and processing of hydrogen on DB
Grey, green, purple, blue, yellow, turquoise, brown and black.
The Kyoto Protocol a brief reminder on DB
Adopted in 1997, ratified in 2005..
Europe moves to phase out electrical SF6 gas
Sulphur hexafluoride the world’s most potent GHG.
Biomass boiler market on the rise in Europe
Proving to be a driver for decarbonisation targets.