I was attracted by the title, but can't be arsed reading the whole thread (it is a Tacky thread, after all). But I just thought I'd throw in that with the mid-Atlantic Rift constantly growing, plus earthquakes etc associated with that, it would never work. Possibly if the tunnel floated at a set depth, but that the raises a whole other set of technical issues.
No, entirely impractical. Oh, of course, a Tacky thread.
No, entirely impractical. Oh, of course, a Tacky thread.