Norwegian governments invests in a $40 billion infrastructure project to make a 1,100 kilometer journey between the southern city of Kristiansand and Trondheim "ferry-free" and shorten the 21-hour journey time in half.

Vegvesen ( Norwegian Public Roads Administration) plans to finish the whole project by 2050.

The infrastructure to be built includes many bridges as well as the world's longest and deepest rock tunnel to be bored in the bedrock under the seabed. It will be 392 meters deep and 27 kilometers long.

What is really new is the underwater suspension tunnel. It will be the first such tunnel. The floating tunnel will be suspended 30 meters under the sea level.

When the water is less than 2 km deep, the tunnel will be anchored to the sea ground with cables. In deeper water, it is not possible to drill down the seabed for anchoring foundation, thus the engineers will be using pontoons to "hang" or support the tunnel from the sea surface.