Japan launches fourth and updated Taigei SSK

Kawasaki Heavy Industries (KHI) has launched the fourth Taigei-class diesel-electric submarine (SSK) for the Japan Maritime Self-Defense Force (JMSDF) during a ceremony at the company’s facilities in Kobe City on 17 October.

The 3,000-tonne SSK, which has been named Raigei – translated into “Thunder Whale” – is expected to enter JMSDF in March 2025 following user acceptance trials. Unlike lead boat Taigei (Big Whale) and sister boats Hakugei (White Whale) and Jingei (Swift Whale), Raigei will be equipped with the latest Kawasaki 12V 25/31 diesel engines that offer a higher performance than the present Kawasaki 25/25SB powerplants.

According to the JMSDF, the Taigei-class SSK has an overall length of 84 m, a beam of 9.1 m, a draught of 10.4 m, and a standard displacement of about 3,000 tonnes, which is comparable to the service’s in-service Soryu-class SSKs. It is operated by a crew complement of about 70 and has been designed to support female personnel.

Like the last two boats of the 12-strong fleet of Soryu-class SSKs, Oryu (SS 511) and Toryu (SS 512), the Taigei-class is equipped with lithium-ion batteries supplied by Kyoto-based GS Yuasa for extended underwater endurance and range. Japan is the first country to successfully field SSKs that employ lithium-ion battery technology, as opposed to conventional lead-acid batteries.

The Taigei-class alsos employ a new advanced combat management system (CMS) comprising integrated command and control (C2), sensors, and weapons systems. These include the OYX-1 processing system, ZQX-12 submarine tactical display system, ZQQ-8 fibre-optic array sonar system, NZLR-2 electronic support measures (ESM) system, and ZPS-6H radar system.

In terms of armaments, the Taigei-class is equipped with six HU-606 533 mm torpedo tubes that can launch a variety of ordnance including the new Type 18 heavyweight torpedo. This is expected to replace the in-service Type 89 torpedo and feature enhanced performance and lethality.

Lead boat Taigei was commissioned in March 2022 with Hakugei following in March 2023. Jingei was launched in April 2020 and is expected to enter service in March 2024.

Construction of up to seven boats by 2028 have been authorised under the MoD’s 2018 Mid-Term Defense Program (MTDP), although it is believed that production could be further extended.

by Jr Ng