According to KHI, this submarine will succeed the Taigei-class, which is the latest submarine class currently being fielded in the JMSDF fleet. Compared to existing JMSDF’s submarines, this new concept brings several new features.
First, in previous submarines the sails have been positioned forward of the hull, but in this concept it is placed aft. In addition, the concept is equipped with bow diving planes, whereas in previous designs, Japanese submarine were typically equipped with sail diving planes. KHI emphasizes increased maneuverability in this concept, and the bow planes are probably related to this.
KHI is also participating in a study currently being conducted by the Japanese Ministry of Defense (MOD) on the loading of standoff missiles on submarines. The most important aspect of this project is the presence of VLS. In this concept, the VLS would probably be fitted between the sail and the bow which is unusual.
Other details are still unknown, but the propulsion system is diesel-electric, not nuclear.
How will the JMSDF operate its future submarines?
KHI has identified the following four key points in the new submarine.
(1) High stealth technology
(2) High detection technology
(3) Improved maneuverability
(4) Carbon dioxide removal technology
With regard to (1) through (3), this probably anticipates future changes in submarine operations in the JMSDF. Previously, JMSDF submarines have been deployed in straits and chokepoints where other countries’ vessels transit, from the Sea of Okhotsk in the North to the East China Sea in the South, where their mission is to gather information in peacetime and to sink enemy vessels in war time. However, the proliferation of SLBM-capable submarines (from North Korea for example), and the increasing trend of standoff missiles aboard submarines will change the way the JMSDF uses its submarines
First, dealing with North Korea’s SSB and the rumored SSBN that is expected to be built in the future is an urgent issue for Japan. To deal with this situation, JMSDF submarines will need to operate in North Korea’s coastal areas. Furthermore, when it comes to monitoring the movements of SSB/SSBN, more underwater maneuverability is required than ever before. In addition, of course, as the performance of enemy submarines improves, detection capabilities must also improve.
Also, the loading of standoff missiles on submarines does not simply mean that JMSDF submarines will change from traditional passive operations to active operations. This means that submarines will be embedded within the integrated firepower that supports the Japan Self-Defense Forces’ (JSDF) cross-domain operations. Traditionally, JMSDF submarines have been a presence that has forced psychological pressure on opponents. But with their new VLS-equipped submarines, the Japanese submarine force will also be a presence that can further cause nervousness in opponents by being able to attack from any directions with standoff missiles.
