World's Largest Ship Tunnel Will Go Straight Through Norwegian Mountain

This illustration shows that the proposed Stad Ship Tunnel would need a terraced exterior for structural support. Kystverket/Norwegian Coastal Administration/Snhetta

On Norway's western coast you'll find the Stad Peninsula. With no offshore islands around it to block rough seas and strong currents, the region is treacherous for ships to navigate. The area gets as many as 106 stormy days each year, with heavy waves that can continue for days after the weather passes. But building a canal, like in Panama or Suez, to avoid the coastline would be pretty much impossible, since the mountainous landscape rises to a peak of more than 2,100 feet (640 meters) above sea level.

The yellow bar at the center of the map shows the proposed site of the Stad Ship Tunnel.
Kystverket/Norwegian Coastal Administration

That's why the Norwegian government has announced that it's moving ahead with a plan to blast a passageway under the rugged peninsula. The proposed Stad Ship Tunnel will be 1 mile (1.6 kilometers) long, 121 feet (37 meters) tall and 86 feet (26.2 meters) wide.

But it won't be easy. The $270 million tunnel, which officials hope to complete by 2023, will require blasting through 7.5 million tons (6.8 million metric tons) of rock, according to Wired UK. It won't be the world's longest tunnel, but it will be the largest when considering depth and interior volume.

The tunnel isn't a new idea. Norwegian newspaper editor Livius Smit first proposed it back in 1874, according to the news site Norwegian American. And during World War II, German occupiers contemplated building the tunnel to protect their naval ships from Allied attacks, though the war ended before they could give it a try. Since the mid-1980s, various public and private-sector organizations in Norway have been trying to work out the details of the gargantuan enterprise.

Maritime Journal reports that the tunnel will be created by first drilling horizontally and using explosives to carve out the roof section. After the roof is built, the rest of the tunnel will be dug out to a depth of 39 feet (12 meters) below sea level. Plans for the tunnel call for sculpted openings and an LED lighting system to make the inside bright. According to the Norwegian Coastal Administration, who are in charge of the project, a feasibility study's currently underway and construction could start as early as 2018.

The proposed tunnel would be sized to accommodate large ships.
Kystverket/Norwegian Coastal Administration/Force Technology