Japan’s Taigei-Class “Big Whale” Submarines: Why They Matter Now
The Imperial Japanese Navy (IJN) during World War II had a large and deadly submarine force.
Perhaps its most famous sub was the I-168, which sank the beloved USS Yorktown (CG-48) during the Battle of Midway.
After World War II, Japan pursued a decidedly pacifist foreign policy, and accordingly the post-IJN Japan Maritime Self-Defense Forces (JMSDF) kept a much smaller but very technologically capable submarine force.
Taigei-Class Submarine. Image Credit: Creative Commons/JSDF.
Taigei-Class. Image Credit – Creative Commons.
Taigei-class. Image Credit: Creative Commons.
Image: Creative Commons.
Now, thanks to the growing menace from East Asian communist dictatorships China and North Korea, Japan has slowly but surely conducted a hawkish turnaround in its military policy, starting with the late Shinzo Abe and continuing with his successors Fumio Kushida, Shigeru Ishiba, and Sanae Takaichi. Japan’s more muscular military is exemplified by the JMSDF’s newest submarine class, the Taigei- (“Big Whale”) class boats.
Taigei (“Big Whale”) 29SS-Class Initial History
Designed as the immediate successor to the 16SS Sōryū-class of submarines, the 29SS Taigei-class subs are built by Mitsubishi Heavy Industries and Kawasaki Heavy Industries (both of whom were famous for building fighter planes during WWII, especially the Mitsubishi A6M Zero). They are designated as attack submarines.
The lead ship of the class is the eponymous JS Taigei, which was laid down on March 16, 2018, launched on October 14, 2020, and commissioned on March 9, 2022. Since then, three more Taigei-class boats have been commissioned and placed on operational status:
-JS Hakugei (“White Whale”), laid down January 25, 2019, launched October 14, 2021, and commissioned on March 20, 2023
-JS Jingei (“Swift Whale”), laid down April 24, 2020, launched October 12, 2022, and commissioned March 8, 2024
Taigei-Class Submarine. Image: Creative Commons.
-JS Raigei (“Thunder Whale”), laid down March 26, 2021, launched October 17, 2023, commissioned March 6, 2025
“Big Whale” and “Swift Whale” are homeported at Yokosuka, while “White Whale” and “Thunder Whale” are homeported at Kure. According to Naval News, “The Taigei-class for the first time has female-only compartments such as a living space for up to six women, according to the service.”
Meanwhile, two other boats in the class, JS Chogei (“Long Whale”) and Sogei (“Blue Whale”) have been commissioned and are expected to officially enter active-duty service in March 2026 and March 2027, respectively. Two more have been laid down but have yet to receive a name or a launch date.
Taigei-Class Tech Specs and Vital Stats
Courtesy of Seaforces-online:
-Displacement: Unknown (submerged) / 3,000 tons (surfaced)
Hull Length: 84 meters
-Draft: 10.4 meters
-Propulsion: 2 x Kawasaki 12V25/25SB diesel engine or 2 x Kawasaki 12V25/31 diesel engine; 6,000 hp (4,475 kW), 1 shaft / 1 propeller
-Max Speed: 20 knots
-Range/Endurance: Unknown
-Crew Complement: 70 commissioned officers and enlisted seamen
-Armament: 6 x HU-606 21-inch torpedo tubes with a mix of Type 89 or Type 18 torpedoes; UGM-84 Harpoon SSM (surface-to-surface missiles)
Though not nuclear-powered, the Taigeis do have greater endurance and submerged speed than conventional diesel-electric submarines thanks to a large number of lithium-ion batteries.
“Big Whale” vs. “Shark”: A Size Comparison
As impressive as the JMSDF’s “Big Whales” are, they still pale in size compared to the “Sharks” of the Russian Navy, i.e. the Akula-class submarines.
While now officially retired, the Akulas remain the largest submarines ever built (and arguably the most famous in Western pop culture, thanks to The Hunt for Red October.
The double-titanium-hulled Akulas displaced 48,000 tons submerged and bore a length of 574 feet, thus easily dwarfing Japan’s “Big Whales.”
About the Author: Christian D. Orr, Defense Expert
Christian D. Orr is a Senior Defense Editor. He is a former Air Force Security Forces officer, Federal law enforcement officer, and private military contractor (with assignments worked in Iraq, the United Arab Emirates, Kosovo, Japan, Germany, and the Pentagon). Chris holds a B.A. in International Relations from the University of Southern California (USC) and an M.A. in Intelligence Studies (concentration in Terrorism Studies) from American Military University (AMU). He is also the author of the newly published book “Five Decades of a Fabulous Firearm: Celebrating the 50th Anniversary of the Beretta 92 Pistol Series.”
