The Japan Maritime Self-Defense Force (JMSDF) has revealed that their new submarine has space for 70 personnel, with a length of 84 meters, a beam of 9.1 meters, and a draught of 10.4 meters. The displacement is approximately 3,000 tonnes, which is slightly larger than the previous Soryu-class SSKs, with a size of 84 meters long, 9.1 meters wide, and a depth of 10.3 meters with a standard displacement of 2,950 tonnes.

The construction of the submarine, priced at 71.7 billion yen ($548 million), was completed with a diesel-electric engine producing 6,000 hp.

The security atmosphere in Japan is becoming ever more tense due to increasing submarine forces from China and Russia, along with North Korea’s intentions to possess nuclear submarines. Consequently, Japan – which does not have nuclear submarines with its great cruising and submerging powers – is facing a significant challenge in enhancing the capabilities of its conventional submarines.

The Japanese Maritime Self-Defense Force has been upgrading its submarines with lithium-ion batteries to reduce their environmental impact. The 11th and 12th Soryu-class submarines installed the batteries instead of the standard lead-acid batteries, and the Taigei-class submarines were designed to have them from the start.

Ridzwan Rahmat, a principal defense analyst at Janes, explains that lithium-ion batteries possess a greater energy density than lead-acid batteries, allowing submarines to remain submerged for longer periods. This makes it more difficult for adversaries to detect and expands the range of operations the JMSDF can conduct.

The submarines can be used for more than traditional warfare, such as reconnaissance operations near an opponent’s coastline or delivering special forces personnel.

The Kyoto-based GS Yuasa corporation, specializing in battery systems, supplied the lithium-ion batteries used in the new submarines. South Korea is anticipated to follow suit with the second wave of their KSS-III (or Dosan Ahn Chang-ho)-class submarines.

In March 2020, the Taigei (SS 513) was officially inducted into service. Two years later, in October 2022, Mitsubishi Heavy Industries (MHI) launched Jingei (SS 515), which is meant to symbolize a “speedy whale.” This submarine is anticipated to be commissioned in March 2024.

The Ministry of Defense of Japan has dedicated money to producing four more submarines, SS 516, SS 517, SS 518, and SS 519. KHI is responsible for constructing the first and third ones, while MHI will make the second and fourth.

For the fiscal year beginning in April 2023, the Japanese defense ministry was granted 80.8 billion yen on December 23, 2022, to construct their seventh-class boat.

In mid-December of last year, the Japanese government approved a Defense Buildup Program, which expressed the intention of their Maritime Self-Defense Force (MSDF) to acquire a submarine with a Vertical Launching System (VLS) to obtain submarines which are outfitted with stand-off missiles.

“To gain underwater supremacy, the MSDF will develop a submarine (SS) equipped with Vertical Launching System (VLS) with the aim of acquiring stand-off missiles carrying submarines.”

Advanced diesel engines and related components are anticipated to be installed on the fourth Taigei-class vessel to meet the need for more power to accommodate the VLS. This is becoming increasingly crucial.

The size of the submarine in Japan is predicted to increase in the future due to the installation of the Vertical Launch System, along with the recent high-powered sonar and different unmanned underwater vehicles.

Ultimately, the commissioning of the Taigei class submarines underscores Japan’s commitment to maritime security and its determination to maintain naval superiority. These submarines, with their advanced capabilities and state-of-the-art technology, are a testament to Japan’s engineering prowess and its capacity for innovation. As Japan confronts evolving security challenges in the region, the Taigei class submarines are expected to play a critical role in ensuring the country’s maritime security and projecting its naval power. Moreover, Japan’s investment in its submarine fleet indicates that it intends to remain a formidable maritime power in the future.