MHI/MSDF 29SS SSK project

[Grey Havoc]

Japan begins development of its next-gen attack submarines, the 29SS

Apparently, Japan has commenced research, design and development for the successor to its Soryu-class attack submarines, which entered service in 2009. Thi

www.navyrecognition.com

Mitsubishi Heavy Industries (MHI), Japan’s leading submarine builder, has unveiled provisional designs for what is tentatively being designated as the 29SS submarine design, with the first submarine scheduled to be introduced in service in the late-2020s. The R&D phase will take place from 2025 to 2028, and the first ship of this class will probably be launched around 2031.

It is expected that while the 29SS submarine will retain the general hull form of the earlier Soryu-class vessels, the new vessels will incorporate a range of important design changes, including a substantially reduced sail, which is expected to be blended into the hull with the aim of reducing hydrodynamic drag, helping to lower the noise signature of the submarines, while the dive planes will be moved from the sail to the hull.

Additionally, it is expected that the 29SS will include a pumpjet as opposed to the traditional propeller for propulsion, in a similar fashion to what is expected to be introduced on Australia’s future Attack Class submarines.

29SS will likely retain the same armament as the Soryu boats, which consist of six bow-mounted 533-millimetre torpedo tubes. The submarine can carry up to 30 torpedo-launched weapons, a mixture of Type 89 heavyweight torpedo and the Sub Harpoon anti-ship missile. Although there is a general trend towards installing vertical launch silos behind a submarine’s sail, Japan does not have the missiles to fill them.

 

[Maro.Kyo]

Future Submarine Concept by ATLA from 2016. Some of the technologies are already implemented to the 29SS/Taigei class SSKs, others are still under research. There are other new technologies not depicted in the diagram which are implemented to the 29SS. Generally speaking, not much is known about 29SS overall.


From above, "discharge sound reduction" is a maglev-based discharge system.

 

[Forest Green]

Japan Launches Fifth Taigei-Class Submarine for JMSDF - Naval News

Japan’s Mitsubishi Heavy Industries (MHI) has launched the fifth Taigei-class diesel-electric attack submarine "Chogei" ｢ちょうげい｣ for the Japan Maritime Self-Defense Force (JMSDF).

www.navalnews.com

 

[Scott Kenny]

I still think the Japanese should have kept the AIP Stirling engines, simply replacing the existing lead-acid batteries with lithium batteries. Last time I checked the standards, lithium batteries could reliably hold 5x the capacity of lead-acid, whether by weight or by volume. Plus are able to recharge a lot faster. I'd rather have enough AIP to maintain a slow pace with all the standard electrical draws than use battery capacity for that.

Gotta admit, my mind still boggles at how quickly Japan iterates designs. 7 boats planned instead of the 12 of the Soryu-class, but MHI was awarded a contract for the Taigei-class successor at the end of 2023(!). This suggests a planned production/in service date of 2029 to me, since Japan does not like leaving shipyards idle.

Takes Japan 4 years to build these boats, which is actually LONGER than the US making Virginia-classes... All the Flight 2 and newer boats are only taking the US about 2 years from laid down till commissioned.

 

[barrett]

Defense equipment Agency Technical Symposium 2024

High-efficiency power storage and supply system for submarines
Prevention of hull enlargement and improvement of mobility
Batteries are Lithium-rich type
Miniaturization and higher efficiency of power conversion devices
Miniaturization and densification of battery racks

JMSDF likes Alfa-class submarine