Japan Approves Disclosing Secret Sub Info to Australia
Image Credit: US Navy

Japan Approves Disclosing Secret Sub Info to Australia


This week, the Japanese National Security Council approved sharing technical data on Japan’s submarine technology with Australia.

This Monday, Tokyo also officially announced that it will join the competitive bidding process for a $39 billion contract to build Australia’s new submarine fleet in partnership with Australian industry.

Australia’s defense minister, Kevin Andrews, had invited his Japanese counterpart, Gen Nakatani, to participate in the competitive process during a teleconference on May 6.

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“We have given consideration to defense cooperation between Japan and Australia,” Nakatani said this Monday. “Australia is a strategic partner that shares common values and security interests” with Japan, he added.

According to a Japanese defense official quoted in the Japan Times, what specific data — most of which is considered top-secret — will be shared with the Australians still has to be agreed upon in bilateral negotiations, but it will be strictly limited to what Canberra needs to evaluate Japan’s offer.

As I have written before (see: “Tokyo’s Subs Might not Be Best Option for Australia”) Tokyo’s decision to disclose such information is an unprecedented step — Japan has previously only shared classified technical data with the United States.

Consequently,  the Japanese Defense Ministry was at pains to emphasize that the technology that will be shared will not enable Australia to build a submarine in whole or in part.

Japan’s brand-new, 4,000-ton diesel-electric Soryu-class stealth submarines, made by Mitsubishi Heavy Industries and Kawasaki Heavy Industries, still appear to be the unchallenged front-runners in the weapons deal.

Current versions of the Soryu-class subs are outfitted with a Swedish-made air-independent propulsion system.  However, the Australian government has so far not shown any interest in AIP, preferring a lithium-ion battery option, which will be built into  the next batch of Soryu-class subs.

Whether technical details on this this new lithium-ion battery propulsion system will be shared with Canberra remains an open question, since advanced lithium-ion batteries are one of Japan’s top military secrets.

Australia’s biggest-ever arms deal, meant to replace Australia’s six Collins-class submarines, has been steeped in controversy (see: “Australia’s Botched Sub Bidding Process Upsets Sweden”). Canberra only recently decided to invite France, Germany, and Japan to participate in the 10-month long competitive evaluation process.

The German company ThyssenKrupp AG (TKMS) appears to be Australia’s second choice, mostly due to its experience in submarine exports. France’s Direction des Constructions et Armes Navales (DCNS) is not seen as a serious contender.

According to The Guardian, South Australia’s defense industries minister, Martin Hamilton-Smith, is visiting the state-controlled naval contractor DCNS in France and TKMS in Germany to discuss the submarine tender this week.

The main purpose of his trip is to explain to the bidders South Australia’s capacity to build the submarines, since the Australian government wants the vessels  to be constructed in partnership with Australian industry. The submarine program is supposed to create around 500 new jobs in the country, mostly in southern Australia.

“We have huge credentials as a center for excellence in naval shipbuilding, underpinned by our highly skilled workers,” Hamilton-Smith told The Guardian. “The South Australian government has created a world-class facility at Techport Australia and we are determined to see Australia’s future submarines built here,” he added. “About 120,000 man-years of jobs depend on the future submarine program alone.”

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