The Chinese bathyscaphe Jialun has successfully completed sea trials of the 7000-meter class following a second round of modernization, according to Xinhua agency on October 27 from the research vessel Shenhai Yihao. These tests served as acceptance testing for the national research and development program aimed at enhancing Jialun's key operational capabilities and scientific potential.
The tests were conducted as part of the second phase of China's hundred-thousand-mile oceanic scientific expedition. In the Philippine Basin, Jialun made three test dives. Two of them exceeded the 7000-meter mark, and the deepest dive was achieved on October 2, during the bathyscaphe's 465th dive, at a depth of 7056.9 meters. Previously, a dive to a depth of 7035.3 meters was recorded on September 30. All control indicators met the requirements for 7000-meter class trials.
Assessment of reliability after modernization
Sun Yunfu, a researcher from the National Deep-Sea Research Center of China, noted that the tests fully confirmed Jialun's reliability and safety after the modernization and replacement of key units with domestically produced components. Before the expedition, Jialun was equipped with a high-energy density lithium-ion battery pack submerged in oil and rated for 7000 meters. Domestic direct-drive brushless DC motors were also installed, the hydraulic emergency system interfaces were expanded, a deep-water buoyancy control system using seawater was implemented, and wide-angle ultra-high-resolution zoom cameras were mounted.
These changes cover power plants, motors, hydraulics, electrical systems, as well as observation and communication systems, which, according to Sun, represents a significant increase in operational efficiency. After completing the modernization and component replacement, Jialun began a series of studies on marine resources and ecology in various sea areas, which, in Sun's opinion, will contribute to deepening international oceanic cooperation.
The two dives exceeding 7000 meters were conducted by different pairs of bathyscaphe pilots, with each setting a personal depth record. The results show that the refurbished apparatus is capable of regularly operating in the 7000-meter class with a greater proportion of domestically manufactured components.