South Korea begins to move the salvaged ferry Sewol to a spot 60 meters from the end of Mokpo New Port on February 21 and plans to set it upright on May 31. Once it is upright, efforts to remove beams and other work will be completed by June 14, KBS World Radio reported. The ferry sunk in 2014, killing 304 people in the disaster. Photo: VCG

China has made great strides in technologies used in salvaging large-tonnage sunken ships, an official with the Ministry of Transport (MOT) said on Tuesday.

Key breakthroughs in technologies required to salvage large-tonnage sunken ships - a global challenge - have been made by Chinese salvage specialists, Wang Lei, a senior official with the MOT, told a press conference on Tuesday.

By the end of the 14th Five-Year Plan (2021-25) period, total tonnage of sunken ships salvaged from no deeper than 100 meters underneath sea surface is expected to reach 100,000 tons, as China's salvaging capability receives a major boost, from the current level of 50,000 tons of sunken ships salvaged from no deeper than 60 meters, said Wang, director of the China Rescue and Salvage Center under the MOT.

Through practice and innovation, China has mastered a number of technologies such as underwater scanning and positioning, computer-controlled synchronized hydraulic lifting of sunken ships.

Chinese specialist led the salvaging operation for the sunken South Korean passenger ferry Sewol in 2017. Though the operation, Chinese specialists explored and mastered new technologies such as setting up jacking wires and steel beams on solid seabed and utilizing air bag buoys in irregular submerged compartments of sunken ships.

China has also strengthened research and development (R&D) capacity by relying on innovation-driven growth. A National Key R&D Program of China on the R&D of holistic approach to salvage large-tonnage sunken ship is near fruition.

China currently has more than 10 large-sized salvage and rescue vessels in active service.