Submersible sets record for distance

China's newest unmanned submersible, Qianlong 3, completed a journey of 156.8 kilometers during its second test dive in the South China Sea recently, setting a national record for the longest voyage by an underwater craft, a scientist said on Monday.

Qianlong 3 returns to the mother ship, Dayang Yihao, after its 156-kilometer voyage, which concluded on Sunday. [Photo/Xinhua]

Qianlong 3 began its trip by plunging some 3,850 meters on Saturday. After about 43 hours, on Sunday evening, it finished its journey and was retrieved by crew members aboard the Chinese research vessel Dayang Yihao, Xu Yijun, the craft's deputy chief engineer, told Xinhua News Agency.

The goal was for it to go for at least 30 hours at 2 knots and cover a distance of 60 nautical miles, or 111 km.

"The end test result was great," Xu said.

Qianlong 3's advantages over its predecessors-lower energy use and greater propulsion power-are responsible for the excellent results, he added.

Qianlong 3, which is capable of reaching a depth of 4,500 meters, completed its maiden dive in the South China Sea on Friday. The first dive lasted around nine hours and reached a depth of about 3,900 meters.

Liu Jian, the submersible's chief designer, told Xinhua that the new vehicle will further strengthen China's technological capabilities in deepsea research and development, especially in more complex studies of seabed environments for scientific or mining purposes.