The Japan Maritime Self-Defence Force (JMSDF) commissioned its newest submarine in a ceremony on Tuesday, March 10.
JS Chogei ("Long Whale") is the fifth Taigei-class diesel-electric attack submarine (SSK) ordered by the JMSDF. Construction was undertaken by Mitsubishi Heavy Industries.
Like her sisters, Chogei has a length of 84 metres, a hull diameter of 9.1 metres, lithium-ion batteries for extended underwater endurance, a crew complement of 70, and armament including torpedoes and Harpoon anti-ship missiles.
The Taigei-class SSKs are modified variants of the Soryu-class submarines that have been in service with the JMSDF since 2009.
The Taigei-class boats all utilise a similar overall hull design as the Soryu-class but with a heavier displacement to accommodate advanced sonar and snorkel systems.
The newer submarines were also designed to accommodate lithium-ion batteries, whereas all but one of the Soryu-class boats were originally equipped with traditional lead-acid batteries.
Unlike her earlier sisters, Chogei also features separate accommodation spaces for female crewmembers.