Sea Platforms

Japan outlines submarine modernisation efforts

01 February 2018
A trio of Oyashio-class diesel electric submarines docked at Yokosuka Naval Base. Eleven of these submarines are believed to be in active service, with the first two boats converted into training vessels. Source: IHS Markit/Kelvin Wong

An effort that was initiated by the Japan Maritime Self-Defense Force (JMSDF) to modernise its undersea warfare capabilities in 2012 is on track to deliver the planned fleet of 22 diesel-electric submarines required for the country’s defence needs by the early 2020s called for under the Japanese government’s 2013 National Defense Program Guidelines, according to a JMSDF official.

Speaking at the Undersea Defence Technology Asia seminar at the Asia Defence Expo & Conference Series (ADECS) 2018 in Singapore, Captain Takahiro Nishiyama, deputy director of the Plans and Programmes Division at the Ministry of Defence’s (MoD’s) Maritime Staff Office, revealed that seven of the service’s 82 m Oyashio-class submarines – which have a surface displacement of 2,800 tonnes – have already completed service-life extension work to date.

The seven boats have received extensive refits during their second and third maintenance cycles, which have been planned to bring the vessels to “almost the same level of that of the latest model [Souryu-class] submarine” while extending their service lives.

According to Jane’s Fighting Ships reference, the JMSDF operates 11 Oyashio-class submarines with the lead vessel commissioned in March 1998 and one new boat entering service each year up till 2008, with construction alternating between Kawasaki Heavy Industries (KHI) and Mitsubishi Heavy Industries (MHI). The first two boats, Oyashio and Michishio , have been since been converted to training platforms.

“The rapid technological development and innovation make our submarines obsolete in [just] a few years after their construction,” Capt Nishiyama said. “On the other hand, we are now facing strict constraints in our defence budget and it is not affordable [for us] to maintain the adequate number of submarines by new construction.”

“Therefore, improving performance and life extension is indispensable in order to maintain a capable submarine force,” he added.

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