China links up final tube in mega cross-sea tunnel

A 6,845-meter-long subsea tunnel of the mega cross-sea project closes up on Sunday in South China's Guangdong province, three days after the installation of the tunnel's last tube, according to the Guangdong Communications Group.

This 32-tube tunnel is the world's longest and widest undersea steel shell concrete tube tunnel and forms part of the 24-kilometer Shenzhen-Zhongshan cross-sea link project.

The link connecting the cities of Shenzhen and Zhongshan will play an important role in developing the Guangdong-Hong Kong-Macao Greater Bay Area.

Composed of bridges, man-made islands, a tunnel and an underwater channel, the link is deemed the world's most difficult cross-sea cluster project.

The bridge sections of the link, which extend for 17.2 kilometers, have already been finished. The link is expected to be operational by 2024, and people in the two cities will enjoy a faster travel time of around 30 minutes compared to 90 minutes before.