At 23:26 on August 5, 2022, the first large-scale cross-sea immersed tunnel in northern China, the last immersed E18 pipe section of the Dalian Bay Subsea Tunnel, undertaken by CCCC First Navigation Bureau, was successfully installed. So far, the installation of the immersed tube in the Dalian Bay Subsea Tunnel has been completed.

In 20 months, 18 aircraft carrier-level immersed tubes were precisely installed, creating a new record for the fastest installation speed and the shortest time in the history of the world's cross-sea immersed tube tunnel construction, and writing the "China Speed" and "China Efficiency" in the field of immersed tube tunnel construction. ".

The subsea immersed pipe section of the project is 3,035 meters long and consists of 18 immersed pipes. The standard pipe section weighs about 60,000 tons, which is equivalent to the displacement of a medium-sized aircraft carrier. The radius of the curve section reaches 1,050 meters, which is the largest and smallest in China. Curved section immersed tunnel.

The E18 installed this time is the last pipe section of the whole line. The installation position is between the E17 pipe section and the final joint. The clear distance between the head and tail of the pipe section is only 1 meter. It must be installed by the "filling in the blank" method, facing the narrowest construction water area and the mooring process. The most complex, the smallest installation space, the most difficult sinking control, the most cumbersome withdrawal process, and the most difficult GINA protection at the stern end are the "most difficult" installations.Editor/Ma Xue