Thanks. What do you mean by "the double-raillway..."?
At the beginning when they designed the Channel Tunnel. Now,
As shown, Holland Tunnel is diff. It only has 2 tubes.
At the very beginning, it was very creative to have the idea
of a 2-rail design instead of a single-rail one.
Channel Tunnel, even for train, is too long to ignore ventin
唐宋韵
2024-02-18 08:56:02Thanks. What do you mean by "the double-raillway..."?