Tests of ship, deep-sea submersible successful

The research vessel Dayang Yihao, or Ocean No 1, returned to its home port in Qingdao, Shandong province, on May 3, with officials and researchers saying that deep-sea research facilities aboard the vessel demonstrated outstanding performance.

"China's technological capabilities in deep-sea research equipment design and manufacture have largely improved from research to final application," says Li Bo, an official with the China Ocean Mineral Resources Research and Development Association.

"This is the result of Chinese scientists' drive for self-innovation capabilities amid a longtime blockade on deep-sea techniques developed by other countries," Li says.

The vessel's scientific ocean expedition started on March 20 and lasted 45 days, covering 6,208 nautical miles. The expedition was divided into two parts, with the vessel stopping in Xiamen, Fujian province, along the way.

Qianlong 3, China's newest unmanned submersible, was involved in the second part of the expedition, which began on April 15.

Cai Wei, the chief scientist responsible for the second part of the expedition, says Qianlong 3 finished four dives with complete success, adding it had not been easy to conduct sea trials during two earlier dives, which aimed at testing its comprehensive performance and endurance.

The ocean craft completed a journey of 156.8 kilometers during its second test dive in the South China Sea in late April, setting a national record for the longest such voyage. Its endurance reached 42 hours, 48 minutes, and it traveled at a speed of 2 knots.

The last two dives, tasked with carrying out scientific investigations on natural gas hydrate and polymetallic nodule zones, lasted 64 hours and covered more than 200 km, acquiring an abundance of seabed photos and scientific data.

Cai says the last two dives launched a new mode of paralleling operations for self-made ocean craft and geological sampling equipment, exploring the possibility of cross-regional operations for an underwater craft in the future.

"Qianlong 3's high-performance will improve our country's deep-sea investigation capabilities and efficiency, and more original scientific results are expected to be gained in this area," Cai says.

During the first part of the exploration, Hailong Series submersibles played a big part. Hailong 3 made five dives and Hailong 11000 made three, reaching depths of 4,500 meters and 3,000 meters in tests.

The tests showed that all parameters adhered to their designed standards, providing a solid foundation for final applications in the future, says Chu Fengyou, chief scientist for the first part of the ship's expedition.

This was the vessel's first scientific exploration since its overhaul in 2017. With its improved capabilities, the vessel is better able to work with other facilities and personnel, according to the vessel's captain, Xu Weiwei.

xiechuanjiao@chinadaily.com.cn