Shantou Gulf Tunnel West Line is super-large-diameter cross-sea shield tunnel in Shantou, Guangdong. It is tunnel by CITIC Group.  Contractor China Railway Tunnel Bureau. It is near complete.

Shantou Gulf Tunnel is largest cross-sea shield tunnel in China. It is in 8 degree seismic activity area. Length of tunnel is 6,680 meters. Subsea constructed with two large-diameter TBMs of 15.01 meters and 15.03 meters.

http://big5.xinhuanet.com/gate/big5/www.xinhuanet.com/fortune/2020-08/06/c_1126335351.htm