Dalian Metro Line 5, the first cross-sea subway line in northeast China's Liaoning province, opened to traffic on Friday.
The subway line started construction in 2017. With a total length of 24.48 kilometers and 18 stops, the north-south line, which is the sixth metro line of the port city, connects two of its major urban functional areas.
The subway line is underground all the way and crosses 2,310 meters of sea. A number of independent technologies and equipment have been adopted in the construction to meet the engineering challenges.