Humans are amazing. It may not seem like it at first, what with all of the war and poverty… but we’re really capable of some amazing things. Like building massive bridges and digging huge tunnels. A tunnel is more than just a big hole, it is a statement of intent: We want to bring people together, peacefully, and slightly quicker than was possible before.
Take the Channel Tunnel for example, which since 1994 has tied together old adversaries Britain and France. When it opened, the grand boulevards of Paris and the fried chicken shops of South London got a little bit closer together. Who says that humans can’t get along?
These structures are also huge engineering achievements, and are a demonstration of the power of mathematics, complex supply chains and visionary ideas.
Look at the Oresund bridge, for instance, which links Copenhagen in Denmark with Malmo in Sweden. The two countries wanted to build a fixed link between the two, but also keep the shipping lane open - so they compromised by building a massive bridge which slides into an artificial island in the middle of the sea, which contains the opening of a tunnel that dives under the sea. And yes, it maintains wifi and phone signal throughout, despite crossing the water, going underground, and straddling an international border.
But what’s to come? What is the next, great engineering frontier? Where else can we, magnificent humans, connect up at long last? Read on, to find out about some on-going plans and some crazy proposals.
Fehmarn Belt Fixed Link
Last year construction began on a new tunnel linking the Danish island of Lolland (yes that’s a real island) with the German island of Fehmarn, which is then connected to the German mainland. It’s a bit of a no-brainer, as it replaces either a time consuming ferry link, or a very long round trip via Denmark’s Jutland Peninsula.
At 18km long, the tunnel will use the equivalent amount of steel to 50 Eiffel Towers - and will employ 3000 people across 8.5 years to build. But what’s most interesting is the way it is being constructed. Unlike our Channel Tunnel, which is bored beneath the seabed, the Fehmarn link will be constructed as 79 separate 217m long prefabricated elements, which will be floated out into the sea on a barge, and then submerged and placed in a trench that has been dug at the bottom of the sea. There’s an awesome CGI video demonstrating how it it will work here:
Once complete, you’ll be able to drive between the two countries in ten minutes, or take the train in seven minutes.
Helsinki - Tallinn Tunnel
Finnish capital Helsinki and Estonian capital Tallinn are just 80km apart, but have historically felt a lot further, as during the Cold War Finland became one of the richest countries in Europe, while Estonia remained poor and oppressed by the Soviet Union.
But soon a new 92km tunnel could restore some balance, as plans are afoot to build a tunnel under the Gulf of Finland. The plans are supported by the Mayors of both cities, and now the hope is the European Union will stump up the cash for the proposed rail tunnel. A feasibility study was concluded in 2015 which sounded promising, suggesting that the tunnel could pay for itself within 40 years. It would also for the first time create a land-link between Finland and the Baltics that does not require travellers to pass through Russia, with all of the associated customs-hassle that would entail (as Finland and Estonia are both in the Schengen Zone, it might not even need a passport check).
A new tunnel would also provide a bonus stop on the proposed new Rail Baltica railway which, when construction begins in 2020, will create faster rail links between Berlin, Warsaw, and major cities in the three Baltic states.
Sri Lanka - India Bridge or Tunnel
The island nation of Sri Lanka and India are divided by the Palk Strait - which is just 32km wide at it’s shortest point. In fact, just beneath the surface of the sea there are hidden islands known as Adam’s Bridge, which were supposedly once navigable on foot, before a cyclone in 1480 permanently shook things up and left them underwater. So ever since, travel between the two countries has required a boat or a plane.
There are, however, plans to restore this historic link. At the end of last year The Hindu reported that the Asian Development Bank was willing to pay for a bridge, though as of April this year, the Indian government hasn’t committed to anything just yet.
Gibraltar - Morocco Bridge
The British outpost of Gibraltar, on the southern tip of Spain, and Morocco in North Africa sit just 14km - or 9 miles - from each other. And the conceivable benefits are obvious and huge: For the first time Africa would have a fixed link with Europe, and trade between the two continents could be hugely enhanced. Finally, the Romans’ former Mediterranean Empire would be one again - but this time not united by Roman domination, but by the spirit of cooperation. What a great idea - and hey, 9 miles isn’t much… So building a bridge between the two should be trivial, right? Not quite.
The problem is that the Gibraltar Strait between the two continents sits at the entrance to the Mediterranean Sea. This is a sea passage that needs to remain navigable to the most enormous of container ships and oil tankers, which (thanks to the Suez Canal in Egypt) deliver the fuel and goods we rely on from the Middle East and China respectively. So any bridge needs to be careful not to screw this up.
So far there have been proposals for both a bridge and a tunnel.
In 1996, Prof TY Lin conducted a feasibility study into building a bridge, and concluded that the best way to do it would be to have two 910m tall piers in the middle of the sea - a tall order given that now 20 years later humans are only just managing to construct buildings on land around that height (the Burj Khalifa, the current tallest building is 830m high). Design-wise, it would need to be a hybrid cable-stayed suspension bridge, with road decks of 5km - longer than any ever constructed. And it would have to be built in deep water. Oh… and don’t forget that it would sit on top of a tectonic fault, making it prone to earthquakes.
The tunnel proposals have hit roadblocks too, after geological surveys revealed the rock is much harder to bore through than, say, that found beneath the English Channel. According to The Guardian, in order to simply carry out the surveys of the rocks to find this, the engineers had to invent new boring techniques to handle the sea currents. Engineers have also concluded that the tunnel wouldn’t simply be able to take the shortest possible route, but would need to take a longer 37.7km route, so that the tunnels have the correct gradients to enable trains the required 300m.
Despite these challenges, the tunnel project appears to be still going as of 2013, with both sides still slowly working on plans for this “Afrotunnel”.
The Darien Gap
The Pan-American highway is a 30,000km long network of roads spanning the entire American continent, from Northern Alaska to Southern Chile. It’s theoretically capable to drive the whole way - apart from one tiny gap.
Annoyingly for perfectionists, on the border between Panama and Columbia, when the continent is at its most narrow, there is the Darién Gap - a 160km long break in the road due to marshland, swamp and rainforest. The reason no one has thought to spray tarmac all over it is partially due to the difficulty of building, but also because of the completely reasonable explanation that it would be environmentally disastrous, as the area is known for its biodiversity. There’s also indigenous people who live there, and fears about drug trafficking and violence.
Sadly it doesn’t look like we’ll see a tunnel any time soon - but there does appear to be a small group of people lobbying for it, including mad-looking 93 year old one-time Presidential Candidate Lyndon Larouche.
Bering Strait Bridge
Vice-Presidential Candidate Sarah Palin once famously claimed that she could see Russia from her house which, even if not strictly true, does underscore that despite America and Russia being worlds apart ideologically, they are really only separated by around 50 miles of Ocean.
And bridging this ocean - the Bering Strait - has long been talked about with varying degrees of seriousness. Prof Lin, who also pitched the Gibraltar bridge proposed a crossing in 1958 as an “Intercontinental Peace Bridge”.
Amazingly, despite the strait being just on the edge of the Arctic Circle, conditions might not be too bad - the tidal currents aren’t outrageous, and the sea is only 55m deep - much less than, say, Gibraltar. The sticking point, of course, is the temperatures which typically hit -20. Which would make construction a nightmare.
The other big problem, as identified by the American Society of Mechanical Engineers is that the location of the bridge is very remote, with no towns for 100 miles on either side. This means that there’s very little existing infrastructure from where to build a bridge. Simply reaching the construction site would no doubt involve new roads, tunnels and bridges too - let alone the cost of infrastructure to connect up existing railways and roads with the bridge.
Since Prof Lin’s call for a bridge in 1958, these days campaigners appear to be instead lobbying for a tunnel, which they reckon would cost only $35bn.
But perhaps it all could be worth it - not because Russia offers a great economic prize to the United States, but because of another country that would stand to gain from such a connection: China.
Japan - Korea Tunnel
Another proposed tunnel that could unite former enemies is the proposed link between Japan and South Korea, which are 128km from each other at their shortest point.
The tunnel would still be the longest undersea tunnel in the world by quite some distance, but it would seemingly make a lot of sense given that both are wealthy democracies that have deep economic ties with each other.
In 2009, the then South Korean President Lee Myung Bak ordered a feasibility study, but such a connection isn’t expected to be cheap, at over £50bn.
There are also a number of other obstacles standing in the way, such as the fact that unlike Britain and France, Japan sits on the edge of a tectonic plate - and there are still arguably cultural factors at play, as though the two countries are now friendly they still haven’t buried the hatchet over their historical grievances to quite the same extent we have with France (and to be fair, Korea’s grievance with Japan is much more recent - up until the end of WWII).
And if they can ever build a tunnel, there’s just the small matter of getting their rail systems to play nicely: Whereas South Korea uses 1435mm gauge tracks (same as Britain and much of the rest of the world), Japan uses wider 1067mm tracks.
Irish Sea Crossing
Closer to home now and over the years there have been a number of proposals to connect Ireland with Great Britain. In 2007, the Centre for Cross Border Studies proposed a bridge from Northern Ireland to Galloway in Scotland. It’d have to stretch for 21 miles, and the idea is that it would connect up with trains heading towards Glasgow (and then, presumably, on to London). The cost was estimated at £3.5bn.
In 2004 meanwhile, the Irish Academy of Engineers proposed a 50 mile tunnel this time going under a much wider stretch of the Irish sea - linking Rossiare in Ireland with Pembrokeshire in Wales. It reckoned the journey would take one hour and ten minutes.
Perhaps where both plans fall down is in the economic question of… why? The Channel Tunnel arguably makes sense because it links London - the capital of Britain - with Brussels and Paris, the capitals of Belgium and France. And once the trains get to Kent, it is a relatively short hop to St Pancras. If you were to catch a train from Belfast to London via Glasgow, or Dublin to London via Pembrokeshire, by the time your train had made the hop under or over the sea, there would still be several hours of sitting on a train to go.
And finally, perhaps the craziest proposal of all: If you have a $12tn - yes, TRILLION, dollars to spare then not only would you control 15% of the world’s entire GDP, but you’d also be able to build this completely crazy transatlantic tunnel.
The idea is that rather than tunnel under the Atlantic Ocean, or sit on the seabed (the volcanic Mid-Atlantic Ridge would cause problems), the tunnel would instead float in the water, held in place by a series of cables anchored to the sea floor.
In order to handle collisions with submarines and whales and the like, these cables would be controlled dynamically, giving the tunnel some flexibility - and they would ultimately be positioned by GPS to keep the tunnel in the right place.
As for the sort of trains you’d need, well, conventional trains are simply too slow for such a long journey. So instead we’d have to use Maglev trains, which float above the tracks using magnets… and we’d need to make them capable of travel at 5000mph in order to be viable. And to achieve these speeds? The massive underwater tunnel would have to be a perfect vacuum.
Well, it’s ambitious to say the least - but perhaps don’t bank on taking a trip on it in your lifetime.