Japan's Silent Submarines Extend Range with New Batteries (excerpt)
(Source: Nikkei Asia; published October 05, 2018)
By Kenji Asada
TOKYO --- Japan's first submarine powered by lithium-ion batteries was launched on Thursday, symbolizing domestic defense contractors' hopes that innovations can allow the industry to survive amid renewed pressure from Washington to procure more American military gear.

The 84-meter Oryu was lowered into the water at the Kobe shipyard of Mitsubishi Heavy Industries, the vessel's developer, after being christened with a bottle of sake. The submarine can reach speeds of roughly 20 knots and displaces 2,950 tons. It will be delivered to the Japan Maritime Self-Defense Force in March 2020.

The Oryu is the eleventh submarine based on the Soryu's design. Soryu-class vessels, which started being built in 2005, are among the largest diesel-electric submarines in the world.

But the Oryu is a vastly updated version of the Soryu, the biggest change being the replacement of lead-acid batteries with lithium-ion ones. Mitsubishi Heavy tapped GS Yuasa to supply the high-performance batteries, which store about double the power.

Submarine batteries are recharged by the energy generated by Oryu's diesel engines. The vessel switches to batteries during operations and actual combat in order to silence the engines and become harder to detect. The lithium-ion batteries radically extend the sub's range and time it can spend underwater.

But amid the joyous occasion of the Oryu's launch, Mitsubishi Heavy executives maintained grim expressions. Washington has been pressuring Tokyo to expand procurement of American military gear as a means of cutting the countries' trade imbalance. Such a development would leave Japanese defense contractors with fewer orders. (end of excerpt)

Click here for the full story, on the Nikkei Asia website.


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