On 25 Apr, 08:14, "Avenger" wrote:
I'm referring to the one connecting London to New York. I think it's a
great idea especially the non stop express trains. And the toilet facilities
and other accomodations will be of the same high standards we've come to
expect on the London underground.

There was a marvellous 1972 SF novel called "A Transatlantic Tunnel
Hurrah!" by Harry Harrison, (an Anglophile American) in which he
depicts a kind of parallel-universe situation where the British Empire
still exists and contains the American colonies. Captain Augustine
Washington and Sir Isambard Brassey-Brunel (descendant of Isambard
Kingdom Brunel) get together to link the heart of the British Empire
with its far-flung Atlantic colony in North America. The tunnel is
like a 3,000 mile long series of upside-down Clifton Suspension
Bridges where the cables have te resist the bouyancy of the submerged
tube... Probably out of print long ago.

It was called "Tunnel through The Deeps" in the USA.