The channel tunnel is 31.5 miles long or 50.45 km. That’s the equivalent of 169 eiffel towers stacked on top of each other. 23.5 miles (37.9 km) of the channel tunnel is under the english channel, making it the world’s longest undersea tunnel.
How Long Is the English Channel Tunnel?
The English Channel Tunnel is one of the most ambitious engineering projects of all time. Spanning a length of 31.4 miles, it is the longest underwater tunnel in the world. Constructed between 1987 and 1994, the tunnel connects England and France, allowing travelers to cross the English Channel without ever having to step onto a boat.
The tunnel is composed of three separate tunnels, two of which are used by trains and the third is a service tunnel. The two train tunnels are each 7.6 miles long and run in opposite directions. The service tunnel is a 2.7 mile long tunnel that runs between the two main train tunnels and is used for maintenance and emergency purposes.
The total length of the tunnel is 31.4 miles, which is roughly the same length as the Channel Islands, the longest of which is Jersey. The tunnel is located approximately 150 feet below the sea bed, making it one of the deepest tunnels in the world.
The construction of the tunnel was a massive undertaking, requiring the removal of 1.7 million cubic meters of chalk and the installation of millions of tons of concrete and steel. This made it one of the most expensive construction projects of all time, with a total cost of over $21.4 billion.