MELBOURNE, Australia – Japan has launched the second of a new class of diesel-electric submarines exactly one year to the day that the lead boat of the lithium-ion powered series took to the water.

The new submarine, which has been named the Hakugei, or White Whale, was launched at Kawasaki Heavy Industries shipyard in the city of Kobe on Thursday afternoon Japan time. The submarine will now undergo final construction and sea trials before commissioning into the Japan Maritime Self-Defense Force or JMSDF, which is planned for March 2023.

The Hakugei is the second Taigei-class submarine. This is a 3,000-ton, diesel-electric attack submarine measuring 84 meters (275 feet) long, and was previously known as the 29SS class, named after the 29th year of Emperor Akihito’s reign in Japan.

The first boat of the class, the Taigei, was launched in October 2020 and began sea trials in July this year. It is expected to be commissioned in March 2022.

The commissioning will allow the JMSDF to continue efforts to recapitalize its submarine fleet, with the service keeping some older boats in service as it brought the number of submarines in service to 22.

The decision to increase the JMSDF submarine force from 16 boats was announced in the 2010 national defense program guidelines. It comes as Japan continues to cast a wary eye on China’s military modernization and increasing assertiveness in the region.

Like the last two boats of the preceding Soryu-class and the Taigei, the Hakugei will be equipped with lithium-ion batteries as a power source. Japan has conducted extensive research into the use of lithium-ion batteries on submarines since the early 2000s, and says they require less maintenance and are capable of longer endurance at high speeds while submerged compared to lead-acid batteries.

It is currently the only known country to have operational submarines using lithium-ion batteries.

The upsized submarine force will comprise eight older Oyashio-class submarines, twelve Soryus and the two Taigei-class boats. Japan has already laid down one more Taigei-class submarine and has funding approved for two more, the latest being $602.3 million allocated for one more boat in the defense ministry’s latest budget.

Mike Yeo is the Asia correspondent for Defense News.

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