
Japan has for the first time revealed additional details of its proposal to design and build submarines to replace Australia’s fleet of six Collins-class boats.

This week, the head of a high-powered Japanese delegation, speaking at this year’s Sea Power conference in Sydney, told local media that Japan would transfer 100 percent of the technology involved in building a larger version of Japan’s state-of-the-art 4,000-ton diesel-electric Soryu-class submarine to the Australian submariner community. “Our objective is to have everything available to transfer,” delegation head Masaki Ishikawa said.

In detail, Japan’s proposal includes advanced welding technologies, top-secret stealth technology, combat system integration, lithium-ion batteries as the submarine’s main energy source (with the option for air-independent propulsion to be added later an), and an all-weather snorkel system that can operate even during a typhoon, according to the Australian news website Perth Now. In addition, the sub will feature a U.S. combat system.

Ishikawa also offered further details for the construction process of the vessels, with the Japanese plan calling for hundreds of Australian workers to be sent to Japan for training and constructing a mock-up submarine under the supervision of engineers from Mitsubishi Heavy Industries and Kawasaki Heavy Industries.

He also emphasized that all vessels could be built in Australia, while the option for the first boat to be constructed in Kobe, Japan under Australian supervision remains an option. “Both options have strong points,” Ishikawa said.

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The delegation head furthermore dismissed the language barrier as a problem for Australian-Japanese cooperation on the A$50 billion ($38.8 billion) project. “There is no problem with language and cultural issues,” he said. The recent changes in Australia’s government should also have no impact on the ongoing bidding process, according to Ishikawa: “You have a new prime minister and that has no impact on our proposed strategic partnership.”

In May 2015, Australia invited France, Germany, and Japan to participate in a 10-month long “competitive evaluation process” with each bidder receiving around $6 million to prepare a proposal. (Given specific Australian requirements, an “off-the-shelf” solution is not an option.)

So far, all three bidding countries have agreed to build the submarines in Adelaide, the home base of Australian Submarine Corporation (ASC). To make its offer more competitive, the Japanese government announced this May that it would share top-secret technology, including details about lithium-ion battery systems, with Australia – a first for Tokyo.


The Soryu-class boats currently in service with the Japanese Maritime Self-Defense Force are outfitted with a Swedish-made air-independent propulsion system. However, the Australian government has expressed its preference for a lithium-ion battery option – one of Japan’s most preciously guarded military technologies.

Long considered the frontrunner, Japan has been losing ground to Germany and its offer of the HDW-class 216 diesel-electric sub designed by ThyssenKrupp Marine Systems (TKMS). Unlike their Japanese competitors, the German company has already built over 160 submarines for 20 different international customers.