To drive the west coast of Norway, from the city of Kristiansand in the south to the city of Trondheim, currently takes about 21 hours and requires seven ferry crossings.
To halve the travel time, the Norwegian Public Roads Administration has launched a nearly $AU56 billion project that will include the world’s longest floating bridge and the possibility of a first-of-its-kind floating underwater traffic tunnel.
“In the history of Norway, this is one of the really greatest infrastructure projects ever,” says Kjersti Kvalheim Dunham, who is managing the project. The closest equivalent transport project in Norway is the 308-mile railway from Oslo to Bergen, which was completed more than a century earlier.
Conventional cable-stayed bridges and tunnels won’t work in parts of Norway’s west coast because some of the fjords are simply too deep.
The government’s solution is to build a bridge that would float on pontoons that would be connected to the fjord’s silted seabed with suction anchors. Norway, the United States, Poland, Belarus and other countries already use floating bridges.
Another element to the transportation solution is something that has never built before: a submerged, floating traffic tunnel.
An Italian engineer who works for the public road administration, says the tunnel could be made of concrete to provide ballast and float about 30m below the surface. It could be fastened to floating pontoons or tethered to the sea bed. He says there is something of a global race to see who can build the first floating underwater traffic tunnel.
“When I started working with this type of structure, I felt really excited,” says Minoretti, who came to Norway specifically to work on the E39 project. “You can be an engineer and live your [whole] life without having this chance.”
Researchers are testing some of the potential materials for the bridge at the Structural Impact Laboratory at the Norwegian University of Science and Technology in the city of Trondheim. The lab simulates the effects of a bomb blast on thick slabs of concrete using compressed air inside a giant, blue, steel “shock” tube.
“We want to learn more about how the material behaves,” says Vegard Aune, an associate professor in structural engineering at the university, “what’s the capacity of the material.”
Engineers will then use that information to help design the tunnel accordingly.
The purpose of this bold transportation project is to replace the ferries and slash travel time. Many along Norway’s west coast are skeptical about the transport project because of the huge cost and aren’t convinced it will ever be completed.