The diagrams show the cross-sections of two tunnels, one joining France and Italy and the other joining two Japanese islands.

There are two diagrams,first illustrates the area of Mont-Blanc Road tunnel joining two different tunnels coming from France and Italy,was constructing between 1957 and 1965,while the second one shows the section of Seikan Railway Tunnel in Japan which connects two Japanese Islands, and was developing from 1946 to 1988. Overall,railway tunnel maintained in Japan was […]