It took 5 years for the subsea tunnel of the deep-middle passage to be closed.

Xinhua News Agency, June 11, Guangdong Communications Group released news that the final joint of the world's longest and widest steel shell concrete immersed tube tunnel, the deep middle passage undersea tunnel, was successfully launched. The penetration survey results show that the accurate docking with the east E24 pipe section has been realized. Exactly five years after the construction of the immersed tube steel shell test section of the subsea tunnel began in April 2018, the "undersea Great Wall" finally closed, and Shenzhen and Zhongshan achieved "hand in hand" at the bottom of Lingdingyang.