JFYI, tunnels are not usually built in factories, so you may want to invert yours and call them "tunnels between Europe and USA" and start digging on your side, without moving to the USA.
And this is why it is such a great business for corrupt people. Actually it is cleaner, faster, cheaper and more sustainable to pre-drill a hole in a factory, and then transport it to its final location. Of course there are some organizations who would protest against this technology by any means necessary...
While the pre-drilled holes tend to weight little, the "doughnut" (usually made in reinforced concrete) around them is really heavy, and then there is the problem of size, you cannot usually transport anything wider than 2.50 or 3.00 meters, but you have also limits in height (bridges cross the route are a problem) so you cannot physically transport more than (maybe) a 1/4 of a pre-drilled hole (with its outer concrete shell) with one truck.
(JFTR: this is a shitpost thread that got through. And it deserves responses in kind :) )
Yep, from time to time not being serious for a second is refreshing :).