Transatlantic Tunnel
I recently saw the film Transatlantic Tunnel (from 1935) (apparently also called The Tunnel) on Netflix. It was terrible in the sense that almost every movie from before 1936 was terrible since people didn't really know how to make decent films (except It Happened One Night), but it is also interesting as a period piece.
All sorts of cool technologies are displayed, including Transatlantic Aviation (in single person aircraft), wireless video communication, as well as various plot devices (Allanite Steel, some new drilling technologies etc.). Apparently, after the war (some more prescience here), there is some alliance of the English Speaking Peoples, and Parliament and Congress are connected via Video technology.
The plot (and I am not giving anything away here) is that an engineer-entrepreneur who recently completed the Channel Tunnel (in the 1950s, only off by 40 years or so, this is science fiction), wants to build a tunnel from England to America. He must obtain financing.
His career takes all his time and destroys his marriage. There is an "unforeseen volcano" in the middle of the Atlantic Ocean, requiring a detour, which costs money. The evil financiers want a greater stake in the tunnel in exchange for money (i.e. all of it). It is not terribly unreasonable in the financial side of things, engineers naive about the ways of finance, yet each side needing the other to build infrastructure.
But for the "Unforeseen Volcano", it isn't too unreasonable either as a bit of near future science fiction. Yet, surely if they had those other technologies, they should have been able to detect a Volcano. You know, perhaps they took a submarine to survey the route before digging?
The bigger question is: Why has not something seemingly so obvious (a Transatlantic Tunnel) yet to be built, or even seriously contemplated by serious people? I know, it would have very high fixed costs unless we can somehow reduce tunnelling costs, but this is where R&D might be quite valuable, since there are lots of potential tunnels which are unbuilt due to high initial construction costs. If we could get robots to due the difficult (laborious) bits, drilling might be much, much cheaper.