The Stad Ship Tunnel: The First Full-Size Ship Tunnel in the World

When we think of a modern-day tunnel, we typically imagine it in context to whatever it’s got coming through. The Channel Tunnel between France and the UK, and the Seikan Tunnel in Japan, are meant to serve trains, while Malaysia’s SMART Tunnel or Boston’s Big Dig move traffic congestion underground in order to clear out the streets above. But it’s a lot less frequent that you’d come across a tunnel meant to serve boats—and exponentially less likely than that, is a tunnel of the size and scale that an entire cargo ship could pass right through.

But head over to Norway, and that’s exactly what the Stad Ship Tunnel endeavors to do. Passing 1.7 kilometers, or just over a mile, underneath a peninsula on the Norwegian coast, the Stad Ship Tunnel will be the world’s first full-size ship tunnel when it’s built, and with an expected arrival date just a few years from now, it’ll be reshaping maritime travel in the area in no time.

The Need

The Norwegian coast is one of the most unique on the planet, with just over a hundred thousand kilometers of coastline between the mainland and the nation’s many small islands. That’s the second-longest coastline in the world, just behind Canada, and it’s also exceptionally beautiful, between its deep coastal fjords, its glaciers, and its countless mountain peaks. Unsurprisingly, maritime travel plays a major role in Norwegian life, both for commercial reasons like fishing and shipping, and as a way to get from place to place.

But while the coastline is magnificent, it’s also dangerous, and along the nation’s entire outer edge, there is no place quite so treacherous as the Stadhavet Sea. Located at the corner of the northern coast, where the land begins to wrap around to the northwest, the Stadhavet Sea is a highly unpredictable region. The merger of two ocean currents, from the North Sea and the Norwegian Sea respectively, creates air and tidal patterns that often can’t be anticipated. Many areas of the Norwegian mainland are somewhat insulated from this sort of weather-related chaos, with the country’s many islands creating a safe buffer zone where ships can travel mostly unbothered, but there are no such islands in the Stadhavet Sea.

Even this might not be so bad, if not for the Stad Peninsula: a long, windswept headland that ships must get around, if they are to continue their journey north or south. The area is stormy around 100 days out of each year, and often turns into a bottleneck, forcing ships to wait days in order to navigate the seas and continue onward. Under the water, a jagged topology presents a whole other set of risks for even experienced navigators, and high waves can last for days even after the wind dies down.

But on this part of the Norwegian coast, there’s just no other solution. It’s a similar situation to what sailors faced in the Western Hemisphere, prior to the Panama Canal, where in order to get from, say, New York to San Francisco, one would have to travel all the way down to the tip of South America before coming all the way back up the other side.

The Stad Peninsula is far shorter than the entirety of the Americas, of course, but for its small size, it is exceptionally dangerous; since World War II, thirty-three people have lost their lives there, and Norwegian folklore tells that even the Vikings typically decided to drag their ships over land, rather than risk passage around the Stad Peninsula by sea. Norway has attempted to solve this problem for generations; proposals for either a ship tunnel, or an over-land way to transport boats across the peninsula have been around since the late 1800s, taking advantage of a narrow isthmus at the base of the peninsula that’s under two kilometers wide. But for most of the nation’s history, Norway has been nowhere close to solving the issue of the Stadhavet Sea.

The Solution

The moment for change finally came in 2013, when Norway’s National Transport Plan, a ten-year investment plan that the Norwegian Parliament updates and expands every four years, went up for its regular vote. For the first time, the plan included an allotment to deal with the Stadhavet Sea problem: an investment of a billion kroner, or about a hundred million dollars US, to build a tunnel underneath that narrow isthmus we discussed before. Multiple feasibility studies in the prior few years had found conflicting results on whether a tunnel would actually be worth building, but this sort of financial commitment from the government was at least enough to find an answer to the utility question once and for all. Worst came to worst, and Norway probably wouldn’t have been devastated to just get some of those kroner back.

Norway certainly isn’t new to the art of tunneling; their Laerdal Tunnel, running 24 and a half kilometers, is the longest in the world today. But a ship tunnel would need to be built on a totally different scale, and with completely different engineering requirements, than anything that the world had been seen before. The National Transport Plan specified that the tunnel would need to be 49 meters high and 36 meters wide, capable of handling ships of a weight of up to 16,000 tons—making it large enough to provide passage for Norway’s ferries. At a depth of 12 meters inside the tunnel, the waters would be able to carry most of the world’s passenger and shipping vessels, should they need a way up the Norwegian coast.

No matter where the route was cut through the Stad Peninsula, it would save nearly sixty kilometers of travel for any ship that could fit through, but that figure somewhat undersells the tunnel’s importance. Far more relevant was the fact that it made a journey up and down the entire Norwegian coastline much safer. By 2017, Norway had announced their commitment to a specific route across the isthmus, and before long, a total budget of about three and a half billion kroner were allocated to the project.

Specs and Construction

The plans for the tunnel have changed a bit with time, and current estimates place its overall length at 1,700 meters when discussing the tunnel itself. The external portions of the project add about 250 meters of length in either direction. At present, the total height of the tunnel is planned to be 50 meters, with 33 meters from the surface of the sea to the ceiling of the tunnel.

Building a tunnel of this size will require the removal about three million cubic meters of rock, using conventional blasting techniques. The chosen route runs between two fjords, which ships can then use to travel back toward open sea in relative safety from the elements. Its entrances on either side are expected to feature stacked stone walls, meant to blend into the landscape while providing the best possible structural stability for the tunnel.

The design faces a number of construction challenges, some of which have to do with the simple fact that a full-size ship tunnel hasn’t ever been built before, and others of which relate to the unique demands of the Stad Peninsula. Because local roads aren’t big enough to support construction equipment, both the building materials and the required heavy machinery will have to come in by sea, including by doing the same circumnavigation of Stad Peninsula that the project is supposed to eliminate. The tunnel also poses interesting problems in blasting out the surrounding rock; because the tunnel is so big, it can’t just be blasted out in a straight line.

Instead, it’ll have to be blown up in layers, starting from the top, proceeding the length of the tunnel, and then blasting and excavating downward. This will also require the creation of additional roads and service tunnels, which will be important in case of emergency when the tunnel opens.

As for what to do with all the excess rock, Norway hopes that the addition of the tunnel will create the opportunity to build up the local fishing and other marine industries. The Stad Peninsula’s steep topology is unsuitable for any sort of large buildings—which, by the way, is the reason that Norway’s attempting to build a tunnel here instead of just digging a canal. But since the tunnel will need to be staffed anyway in order to coordinate traffic flow and protect against potential emergencies, that staffing plus the high levels of ship activity create a situation where a larger settlement might make good economic sense. If it’s built, it’ll be on the millions of cubic meters of rock that are currently sitting inside the peninsula, with any factories or fisheries built on that same structure.

Until construction is finished, the seas will be held back from either end of the tunnel by walls of rock. Once those walls are detonated at the end of the construction process, the tunnel will be cleaned out of underwater rubble and cleared for opening. When it opens, the Stad Ship Tunnel is expected to allow the passage of up to 120 ships each day, with traffic flowing one way at a time.

The situation’s not likely to lead to bottlenecks; 120 ships a day would be extremely busy compared to what the Stad Peninsula usually sees. The designs also call for a road and overpass nearby the tunnel, complete with an observation deck so that Norwegians and tourists alike can enjoy watching ships enter and exit. Importantly, Norway has also made clear that it’s constructed the Stad Ship Tunnel with climate change in mind; even if sea levels rise by up to a meter over the next century, the tunnel is expected to be more than able to continue moving ships through.

At present, all required funding for the Stad Ship Tunnel is now in place. Over the course of 2023, Norway plans to finalize a contract for the tunnel’s construction, with an anticipated signing date of early 2024. From there, construction is expected to begin almost immediately, as all of the expected red tape has already been dealt with.

Norway expects somewhere between four and five years of construction after that time, with an anticipated opening date as soon as 2028. And as much as this is the portion where we’d typically get into all of the flaws, delays, and waiting catastrophes…well, there don’t seem to be any to discuss here. Of course, a whole lot of things can change over the next few years, as the Stad Ship Tunnel is built.

But right now, it appears that Norway’s got all its ducks in a row. Once its chosen contractor gets the green light, knock on wood, the project might end up being fairly straightforward. Norway knows how to do this sort of tunnel excavation, all the requisite technology and construction techniques already exist, and the money’s all there.

It’s just a really big tunnel, in a situation where its bigness doesn’t present any extra problems that we could anticipate in advance.

With a traversal time of somewhere around fifteen minutes for a large vessel, the tunnel should quickly move from the role of a globally trailblazing feat of engineering, to a unique, moderately interesting, but ultimately inconsequential part of a standard voyage up and down the Norwegian coast. And by all measures, that would be a resounding success—a relatively quick, painless construction project with a high-quality end result that, ideally, nobody’s ever got to worry about. Fishing vessels, cruise ships, container ships, and passenger ferries will be able to go about their business without having to worry about perilous, exposed seas, and the Norwegian government will have built a new tourist attraction that megaproject enthusiasts won’t want to miss.

As much as the Stad Ship Tunnel is an engineering marvel, it’s also there to keep ships and their passengers safe enough that unless you take a vacation to the Stad Peninsula, you shouldn’t ever have to hear about it again. If it’s safe, if it’s predictable, if it’s timely, and if it’s utterly unremarkable, then the Stad Ship Tunnel will have done its job, regardless of the groundbreaking feats of engineering that made it happen.

Key Takeaways

• The Stad Ship Tunnel will be the world’s first full-size ship tunnel, facilitating safer maritime travel in Norway.
• The tunnel aims to address the dangerous and unpredictable conditions of the Stadhavet Sea and the Stad Peninsula.
• Construction is expected to begin in 2024 and finish by 2028, with all necessary funding already secured.
• The tunnel will be 1.7 kilometers long, 50 meters high, and 36 meters wide, accommodating ships up to 16,000 tons.
• The project includes plans for an observation deck and potential development of local fishing and marine industries.

Sources

• Original MegaProjects video: The Stad Ship Tunnel: The First Full-Size Ship Tunnel in the World
• https://www.kystverket.no/en/fairway/stad-ship-tunnel/#:~:text=Stadhavet%20Sea%20is%20the%20most,a%20safer%20passage%20through%20Stad
• https://web.archive.org/web/20111208204450/http://www.nrk.no/sf/leksikon/index.php/Stad_skipstunnel
• https://www.constructiondive.com/news/worlds-first-major-ship-tunnel-project-to-take-bids-soon/597310/
• https://www.newcivilengineer.com/latest/engineering-challenges-of-building-the-worlds-first-ship-tunnel-19-04-2021/
• https://www.globalconstructionreview.com/norway-plans-ship-tunnel-av7oid-de7adly-stadh7avet/
• https://www.ship-technology.com/features/featurethe-stad-ship-tunnel-a-world-first-5798958/
• https://snohetta.com/projects/334-stad-ship-tunnel
• https://www.kystverket.no/en/fairway/stad-ship-tunnel/
• https://www.kystverket.no/en/fairway/stad-ship-tunnel/faq---stad-ship-tunnel/
• https://www.cnn.com/travel/article/norway-ship-tunnel/index.html
• https://www.dezeen.com/2021/03/17/snohetta-stad-ship-tunnel-norway-architecture/
• https://www.lifeinnorway.net/stad-ship-tunnel/
• https://dozr.com/blog/stad-ship-tunnel
• https://www.ship-technology.com/features/sea-safety-and-the-stad-ship-tunnel-project/
• https://www.forbes.com/sites/davidnikel/2021/03/05/norways-325-million-ship-tunnel-gets-go-ahead/?sh=74884c8556fe
• Hero image source by Jorge Láscar from Melbourne, Australia / openverse, by.

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