submergedtube

A submerged tube is a type of tunnel constructed by sinking prefabricated sections of tunnel into a body of water. These sections, often made of concrete or steel, are built on land or in dry docks and then floated to the desired location. Once in position, they are carefully lowered onto a prepared foundation on the seabed or riverbed. The sections are then joined together underwater, creating a continuous tunnel. This method is particularly suitable for crossing wide bodies of water where a bridge might be impractical or for crossing deep channels.

The construction process involves several key stages. First, the trench or foundation for the tunnel is prepared on the waterway floor. Then, the tube sections are manufactured and transported to the site. These sections are typically sealed with bulkheads to remain watertight during submersion and towing. Once positioned, ballast is often added to the sections to help them sink accurately. After sinking, divers or remotely operated vehicles are used to connect the sections, ensuring a watertight seal. Finally, the tunnel is backfilled and often covered with protective material. Submerged tube tunnels are known for their relatively quick construction time compared to some other tunneling methods, as much of the work is done off-site. They are also used for various purposes, including road traffic, railway lines, and pedestrian walkways.