Key Points and Summary – Japan’s new Taigei-class (“Big Whale”) submarines are its latest “ninjas of the sea,” designed with one mission: countering China’s expanding navy.
-As the successor to the already formidable Sōryū-class, the Taigei features even greater stealth with a new hull design and a “floating floor” system to minimize noise.
-Its most revolutionary feature is the use of advanced lithium-ion batteries, a world-first that provides longer underwater endurance and faster recharging.
-Armed with new Type 18 torpedoes, these submarines are built to dominate the shallow waters around Japan and would be a lethal threat to a Chinese invasion fleet.
Japan’s Taigei-Class Submarines, Ninjas Of The Sea
The Japanese Navy’s Taigei-class submarines (29SS) are a new class of attack submarines developed for the Japan Maritime Self-Defense Force. It is the successor to the Sōryū-class submarine.
The Taigei-class (Big Whale) of diesel-electric attack submarines under construction for the Japan Maritime Self-Defense Force (JMSDF) are conventional diesel-electric submarines rather than nuclear-powered.
The new submarines are bigger, quieter, and more capable than their predecessor boats, which they are replacing. Currently, the Japanese Navy has five of the Taigei class, with more already being procured.
The Taigei-class submarines are 275 feet long with a beam of 29 feet and a draft of 34 feet.
The Taigei-Class Are Designed With One Mission In Mind
With China’s Navy continuing to expand its fleet size and operational areas, it will sail into the First Island Chain between Japan’s Kyushu and the Philippines, which mainly consists of Japan’s southwest islands, and is most likely to operate more frequently in the Western Pacific Ocean around Japan.
The Taigei-class submarines have enhanced stealth, improved combat systems, and superior propulsion technology compared to previous Japanese submarine designs. Key improvements include a quieter hull, a new combat management system, and the use of lithium-ion batteries for extended underwater endurance.
The Taigei-class incorporates a new hull design, and to increase its stealth, a floating floor system and acoustic-absorbing materials are used to minimize noise and vibration, making it harder to detect.
The first three boats of the Taigei class used two Kawasaki 12V 25/25SB diesel power plants as the main engines. However, the last two submarines in the series began using newer-model Kawasaki 12V 25/31 diesel engines with a higher output power level.
The newer diesel engines also incorporate a new “snorkel” power generation system designed to be quieter and generate higher power output, improving functionality and survivability.
The Japanese Defense Ministry says that the Snorkel system streamlines power generation and brings the critical added benefit of supporting advanced on-board power systems to support electronic systems.
Use Of Lithium-Ion Batteries, A First
The use of lithium-ion batteries, instead of traditional lead-acid batteries, provides longer underwater endurance and reduces the need for frequent snorkeling, further enhancing stealth.
Japan is the only nation that has utilized this new technology in submarine design; however, South Korea is reportedly soon to incorporate the lithium-ion batteries in their subs.
The lithium-ion battery advantages include extended battery discharge rates, faster recharge times, and higher energy density, the latter of which is always the primary objective of any submarine power plant. Lead-acid batteries are also less efficient at energy storage than the lithium-ion batteries used in the Taigei subs.
These new batteries provide significantly greater overall performance compared to other conventional undersea submarines.
Taigei-Class SSK Weapons
The Taigei-class employs the same torpedo counter-measures system that has been installed in the last four Sōryū-class boats.
The boat has six HU-606 21 in (533 mm) torpedo tubes for Japan’s newest torpedo, which is called the Type 18, succeeding the previous Type 89. The new torpedo features improvements in a number of areas, including propulsion, target detection, and processing.
The class is also capable of deploying the UGM-84L Harpoon Block II anti-ship missile against surface targets. This missile is designed for striking targets beyond visual range, offering an extended reach for both anti-ship and land-attack missions.
New CMS and Sonar Systems
The Taigei-class features a new Combat Management System (CMS), which is a new system that integrates advanced sensors, command and control, and weapon engagement systems.
It’s designed to enhance situational awareness and facilitate rapid responses to threats. The CMS works in conjunction with other advanced systems like the ZQQ-8 high-performance fiber-optic array sonar system and the ZPS-6H radar for surface and low-level air search.
X-Shaped Rudder
The X-shaped rudder configuration, rather than the normal cruciform shape, provides superior maneuverability, particularly in shallow or confined waters. This design allows for more precise and responsive control, making the submarine more agile underwater.
The X-shape can also help reduce the risk of damage to the rudder when a submarine rests on the seabed.
The Taigei submarines are one of the best diesel-electric boats in the world. With Japan beefing up its submarine fleet with these boats, it will help in checking Chinese expansion in the region, especially if China decides to invade Taiwan. The Taigei could be used with significant effect on Chinese amphibious ships.
About the Author: Steve Balestrieri
Steve Balestrieri is a National Security Columnist. He served as a US Army Special Forces NCO and Warrant Officer. In addition to writing on defense, he covers the NFL for PatsFans.com and is a member of the Pro Football Writers of America (PFWA). His work was regularly featured in many military publications.
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