China’s Jiaolong 3-man submersible is en route to an attempt to set a new world depth record for self-propelled vehicles by descending 7,000 meters (23,000 feet or 4.4 miles) into the Marianas Trench in the far western Pacific.
The current record for such vehicles was set in August 1989 by Japan’s Shinkai which attained a depth of 6,527 meters.
The solo 6.8-mile dive that filmmaker James Cameron made on March 25 matched the world depth record set in 1960 by the US bathyscaphe Trieste carrying a two-man crew — US Navy Capt. Don Walsh and Swiss engineer Jacques Piccard. Cameron’s dive was a record by virtue of the fact that he was diving solo.
What will make Jialong’s dive on Sunday a record is that, unlike Cameron’s “vertical torpedo”, it carries a crew of three and is self-propelled. Both factors add immensely to the challenges of building a structure that can function while withstanding the horrific pressures at that depth. Pressure increases one atmosphere (atm) for each 10 meters of depth. One atm means about 10 metric tons of weight on an area of one square meter. Mechanical systems that work at lesser depths can simply freeze up at the depths Jiaolong will be attempting.
Jiaolong carried three people to a depth of 5,188 meters in international waters in the northeastern Pacific last year. That depth gives the submersible access to more than 70 percent of the Earth’s seabed.
A successful 7,000-meter dive would give it access to 99.8% of the world’s ocean floors and would surpass the capacities of existing and planned submersibles built by the U.S., Russia, Japan and France which have been at the forefront of deep-sea exploration.
Among currently operational vehicles, two Russian MIR submersibles can attain 6,000-meter (19,685 ft.) depths. The US National Science Foundation is currently retrofitting the submersible Alvin to be capable of attaining a depth of 6,500 meters.
China became only the fifth nation to send humans below the 3,500-meter mark in 2010 with a series of dives that reached 3,759 meters between May 31 and July 18.
Unlike Cameron’s cramped Deepsea Challenger — which has an interior diameter of only 4 feet — Jiaolong is considerably more spacious and possesses undersea mobility systems that allow it to maneuver on its own for limited distances along the seabed. The craft was built by China using many parts acquired from several other nations. It is named after a mythical sea dragon.
