The immersed tube method, a version of the cut and cover technique, is a cheap and easy way to construct a tunnel under water -- and it's generally the fastest way. Here's how it works ...

A once-in-a-generation construction project ... the $8 billion Fehmarnbelt tunnel will be both the longest combined road and rail tunnel and the longest immersed tunnel anywhere in the world.

ALSO READ| Top 10 Longest Bridges In the World 2023 Diverse techniques are employed in the construction of underwater tunnels, encompassing both the immersed tube and submerged floating tunnel ...