The Shenqian, currently the most advanced deep-sea salvage and exploration ship in service with the Chinese Ministry of Transportation. Photo: Xinhua

The state-owned China Shipbuilding Industry Corporation has buckled down to build the nation’s first long-endurance offshore salvage vessel at its plant in the eastern coastal city of Qingdao.

The 177-meter hull of the not-yet-christened deep-diving ship will displace 13,280 tons as one of the largest of its kind, boasting an endurance of 10,000 nautical miles to expand China’s deepwater operating capacity from 3,000 to as deep as 6,000 meters.

Its construction will take two years, with expected delivery to the Ministry of Transportation’s Shanghai Rescue and Salvage Bureau by 2020, according to the People’s Daily.

The colossal vessel will be able to support laying of submarine communications cables at a depth of 3,000 meters and deepwater hoisting at 6,000 meters.

CSIC engineers said they had to develop indigenous solutions for manned saturation diving – a cutting-edge technique that allows divers to reduce the risk of decompression sickness when they work at great depths for prolonged periods of time – as they failed to seek technology transfer from overseas.

Saturation diving is widely used in wreckage recovery, underwater construction and exploration.

The voyage to the ocean bottom is still a challenging experience, and scientists in China and overseas are working to find ways to study this extreme environment from shipboard.

With more sophisticated use of fiber optics, satellites, and remote-control robots, scientists believe that one day they will be able to explore the deep sea from a computer screen on the deck rather than out of a porthole.

The new ship under construction marks the new depth of China’s ocean salvage and exploration, compared with the most advanced deep-diving support vessel, the Shenqian (literally deep-diving), that is currently in service.

In March 2017, the Shenqian took part in the salvage of the sunken wreck of the South Korean ferry Sewol-ho in the sea off South Jeolla province.

The crew from the Shanghai Salvage Bureau pumped water out of the ferry’s ballast tanks and attached air bags to increase its buoyancy before lifting the carcass out of water and attaching it to a barge.

China’s remote-operated vehicles are also seeing increasing use in underwater exploration in the South China Sea as well as the Indian Ocean. These submersibles are piloted through a cable that connects to a surface ship, and they can reach depths of up to 6,000 meters. New developments in robotics have also led to the creation of autonomous underwater vehicles (AUVs).