Japan Targeting Dokdo... This Time with Attack Submarines

[Senior Researcher Chansu Kim, Maritime Underwater Research Team 1, Defense Technology Quality Institute] Japan has expanded its submarine force to 22 vessels with the launching of its first new diesel-electric submarine.

The new submarine, named Taigei, meaning "big whale," was launched on October 14 at the Mitsubishi Heavy Industries shipyard located in the Kobe area. This submarine is the first vessel in the follow-up class to Japan's current Soryu-class submarines.

The Taigei is a 3,000-ton diesel-electric attack submarine measuring 84 meters (275 feet 7 inches) in length. The design of this submarine was previously named the 29SS-class in commemoration of the 29th anniversary of Emperor Akihito's reign. Its power source is a lithium-ion battery.

Since the early 2000s, Japan has been researching the use of lithium-ion batteries in submarines. These batteries require less maintenance and allow for longer high-speed underwater navigation compared to lead-acid batteries. Japan is the only country operating submarines powered by lithium-ion batteries.

After completing sea trials, the Taigei will be delivered to the Japan Maritime Self-Defense Force in 2022 and commissioned. Once operational, the Maritime Self-Defense Force will possess its 22nd submarine.

The expanded submarine force is expected to consist of 9 older Oyashio-class submarines, 12 Soryu-class submarines, and 1 Taigei-class submarine. Japan plans to acquire two additional Taigei-class submarines, and the Ministry of Defense has requested a budget of $654.1 million to procure one more submarine.

In 2010, Japan announced in its National Defense Program Guidelines a decision to increase its submarine fleet from 16 to 22 vessels. This plan was made while continuously monitoring the modernization activities and aggressive behavior of the Chinese military in the region.