Thanks. What do you mean by "the double-raillway..."?

所有跟帖： 

• At the beginning when they designed the Channel Tunnel. Now, -妖妖靈- ♀ (5785 bytes) () 02/18/2024 postreply 09:07:13

• As shown, Holland Tunnel is diff. It only has 2 tubes. -唐宋韻- ♂ (0 bytes) () 02/18/2024 postreply 09:11:13

• At the very beginning, it was very creative to have the idea -妖妖靈- ♀ (0 bytes) () 02/18/2024 postreply 09:16:35

• of a 2-rail design instead of a single-rail one. -妖妖靈- ♀ (0 bytes) () 02/18/2024 postreply 09:17:59

• Channel Tunnel, even for train, is too long to ignore ventin -唐宋韻- ♂ (0 bytes) () 02/18/2024 postreply 09:17:44