Transatlantic Tunnel (opens in new tab)

Orkney-Shetland ~100km, Shetland-Faroe ~300km, Faroe-Iceland ~450km, Iceland-Greenland ~350km, Greenland-Canada another 350km.

Current undersea tunnels max-out at 30-40km.

It'd be hard but i see it plausible.

This has the same drawback as the hyperloop as far as being one long line of potential single points of failure. If the train is going fast enough to be economical, it can be catastrophically destroyed with minimal interference. At those energies repairs would be non-trivial. Unfortunately we need a safer world to build this project than one where state actors destroy major pipelines and bridges as a routine part of economic warfare.

This is a concept I stumbled across a few years ago, and have mentioned a few times on HN, usually in other transportation modality threads.

If you look at globe of the world, it turns out that there's not too much water preventing a globe-spanning land-based transportation network, with the exceptions of the Atlantic Ocean (standing between the shortest-link routes between Europe and North America and Africa and South America), and of course, Antarctica. Otherwise, the Bearing Strait, some island-hopping through Indonesia to Australia, and a few other not-overly-implausible links ... suggest themselves.

(New Zealand's also something of an outlier.)

But the Atlantic is a bear.

My thought is that a submerged floating tunnel, as has been proposed for the E39 fjord-spanning highway in Norway. Of course, there's a slight difference in scale between spanning a few km and few thousands of km.

<https://en.wikipedia.org/wiki/Submerged_floating_tunnel>

<https://en.wikipedia.org/wiki/European_route_E39>

<https://nationalpost.com/news/norway-is-building-the-worlds-...>

Given costs and safety concerns, constructing a few smaller and shorter spans (say, from Great Britain to outlying islands, the Faroes, Iceland, or from Canada to its offshore islands), and piloting the project as an automated cargo-only link (24/7/365 rapid delivery without any weather concerns) might be one way to bootstrap the project.

Even based on some very rough estimates based on extant projects, a full Atlantic tunnel might easily run to a trillion dollars. Which is fairly considerable.

Though the promise of decarbonised transoceanic cargo and passenger travel at speeds not incomparable with present-day passenger jet aircraft is appealing.

<https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...>

Technically, most real solution is tunnel over Bering strait. It is just 83 water km.

But this part of world have so huge political problems, so no large project will built until resolve them.