FLOATING TUNNELS CUT TRAVEL TIME

In a bid to cut motorists’ travel times around the country’s innumerable fjords and inlets, the Norwegian government wants to develop submerged floating tunnels anchored 30m below the surface. Fixed in position with cables and made of concrete, the tunnels would transport vehicles from one end of a fjord to another.

More than 1,000 fjords punctuate the Scandinavian country’s west coast – a region that’s home to a third of the country’s 5.3 million inhabitants. Currently, the 1,100km journey between the southern city of Kristiansand and Trondheim in the north via the west coast takes 21 hours and requires seven ferry crossings.

The government plans to cut this by half with a $40 billion infrastructure project, making the route ‘ferry-free’. In addition to the underwater tunnels, the plan includes bridges and the world’s deepest and longest rock tunnel – drilled through bedrock under the seabed – measuring 392m deep and 27km long.

The Norwegian Public Roads Administration (NPRA), the governmental body responsible for the project, aims to complete construction by 2050. It acknowledges that the project’s biggest risks are explosions, fire and overloading.

NPRA is working with the Norwegian University of Science and Technology’s Centre for Advanced Structural Analysis (CASA), using live explosives to “investigate how tubular concrete structures behave when subjected to internal blast loads,” says CASA researcher Martin Kristoffersen.

Maybe a solution to another harbour crossing for Auckland?