Japan is bolstering its submarine fleet strength, introducing some of the most advanced and undetectable vessels to its flotilla to stay ahead of China.

On Monday, Japan’s Ministry of Defense was presented with the Hakugei, the second vessel of the Taigei-class diesel-electric submarines, from Kawasaki Heavy Industries. This submarine is outfitted with lithium-ion batteries, allowing it to stay submerged for extended periods and run silently.

The history of Japan’s submarines is fascinating. During the Pacific War, Japanese submarines were responsible for sinking two US aircraft carriers and damaging several other ships. Japan started the war with 63 ocean-going submarines and grew its fleet to 111 during the war. According to the US Naval Institute, the Imperial Japanese Navy developed the submarine faster than any other country. By World War II’s beginning, Japan possessed one of the world’s most powerful submarine fleets. As part of the attack on Pearl Harbor on December 7, 1941, five Type A midget submarines were sent to surround Oahu and sink ships. After the war, Japan continued to step up its submarine development.

The Japanese submarine force was integral to their strategy during World War II. They used their submarines to launch surprise attacks against Allied forces to gain an advantage in battle. The Japanese also used their submarines to transport supplies and personnel to distant locations without being detected by Allied forces. In addition, they employed their submarines as reconnaissance vessels to gather intelligence on enemy movements and activities.

The effectiveness of Japanese submarines during World War II was primarily due to their advanced technology and tactics. Their torpedoes were more effective than those used by Allied forces, allowing them to target ships more effectively from greater distances. Furthermore, Japanese submariners had arguably superior training to their Allied counterparts, which allowed them to operate more efficiently underwater and remain undetected for longer periods.

Despite having some advantages over Allied forces, Japanese submarines suffered significant losses during World War II due to technological limitations and strategic errors made by military commanders. For example, many Japanese submarines lacked radar systems, making it challenging to detect enemy vessels before they could be attacked or destroyed by Allied forces. Additionally, some commanders should have considered factors such as weather conditions when planning operations, resulting in costly mistakes that cost lives and resources.

Japan’s Hakugei

On March 20, the Japanese Navy welcomed the Hakugei, a diesel-electric attack submarine, into their fleet. This is the second vessel of its class, the Taigei-Class. These submarines have improved underwater endurance in comparison to their predecessors.

At a ceremony hosted by Kawasaki Heavy Industries (KHI) in Kobe City, Hyogo prefecture, the newly christened JS Hakugei (SS 514) was welcomed into Escort Division 1 of Escort Flotilla 1, which is based at the Kure naval base in Hiroshima prefecture.

In Japanese, “Hakugei” literally translates to “white whale.” The Taigei class of submarines have names that include the kanji for “whale,” following the Shio (tide) and Ryu (dragon) series used on earlier submarines. “Taigei” is the Japanese expression for “big whale.”

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.