Dramatic pictures from Japanese media show the Japan Maritime Self-Defense Force (MSDF) submarine Soryu on the surface with a damaged conning tower and her starboard diving plane mangled. The Soryu is believed to have surfaced beneath a 50,000-ton Chinese Freighter named the Ocean Artemis which had set sail from Japan on Friday with a load of iron ore. Three minor injuries to the crew of the submarine have been reported.
When the Soryu surfaced she appeared to have had her communications antenna deployed from the conning tower (also called the Sail) which was carried away in the collision. According to a statement released by the Japanese Minister of Defense Kishi Nobuo, the resulting damage to the comms antenna required the vessel’s crew to contact Naval Headquarters using a cell phone three hours after the accident, presumably when in cell phone range to the shore.
The damage to the freighter is believed to be negligible and the government of Japan has issued a statement expressing regret to Communist China. The MSDF of Japan operates 11 submarines of this type in its fleet. The Soryu (SS-501) had her keel laid down in March 2005, was launched in December 2007, and commissioned in March of 2009. The name “Soryu” means green (or blue) Dragon; it was also the name of an Empire of Japan fleet carrier in WWII.
This type of submarine is rather unique in that it uses a combination of a diesel engine and a large bank of lithium-ion batteries rather than the traditional lead-acid type. These batteries, while very expensive, are believed to allow the Soryu to remain submerged for up to 30 days and run at a top speed of 20 knots. These batteries also have a reputation for catching fire when they overheat, so the Japanese Navy must have mitigated that risk with very good fire suppression systems.