Technical issues and the Soryu - Lithium-ion batteries no AIP

A bank of lithium-ion batteries (LIBs) for marine use. LIBs are being developed and offered for future Japanese, German, French and probably Swedish submarines.

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The new batch of around 6 Soryus being built for the Japanese Navy (known as Japan Maritime Self-Defence Force (JMSDF)) over the next 8 years will be built around Lithium-ion batteries (LIBs). LIBs represent a very significant technical departure from the existing lead acid batteries. This influences the structure of the submarine's entire electrical system (wires etc) not just the batteries themselves.

Use of LIBs may allow a submarine to stay submerged for a longer time than lead acid batterries as long as the submarine is not driven too quickly for too long as this runs the batteries flat.

Air independent propulsion (AIP)

Some confusion has been created that LIBs are some separate component replacing  air independent propulsion (AIP). This is basically untrue. LIBs are replacing lead acid batteries in new submarines to be built from around 2015. LIBs cannot be retrofitted to replace lead acid batteries in individual submarines already operating. Any battery, LIB or lead acid, will almost always rely on regular recharging from a submarine's air dependent diesel engines. Some AIP technologies can charge batteries - but there are downsides-tradeoffs. The relatively few subs in the Asia-Pacific region that have AIP (none are Australian) might still use AIP even if they are in future built with LIBs. Those that use AIP might typically want their subs capable of a close to shore (closed shallow waters, littorals, straits and harbour mouths etc) near motionless, defensive missions of up to 3 weeks submerged.

AIP, unlike batteries, cannot be recharged during a mission.

AIP has been compared (by submarine sales teams and the mainstream media) to nuclear propulsion. This is not true. AIP might allow a submarine to move at 20+ knots for 5+ hours while a nuclear reactor can run at 30+ knots for 3 months or until a crew's food runs out.

Australia decided not to use AIP in the Collins class due to Australian submarine mission profiles which need much diesel for long range rapid transit. This is even though Australia bought its subs from Kockums who are AIP experts. I haven't heard of any Australian interest in AIP for the future submarine. It is unclear whether Singapore's two HDW 218SG's on order will use AIP (but likely) and LIBs (maybe). Some Chinese subs are believed to use AIP, most likely mainly in defensive mode, not far offshore.

AIP is basically a 200 ton plug in the submarine for inclusion of a small engine and storage of extra fuel, alcohol or hydrogen and an oxidiser. The first batch of 6 to 7 Soryus (up to SS-507?) do operate with Swedish designed Stirling engine AIP technology. The next 6 Soryu will most probably use LIBs.

The downsides of using AIP include: dangerous highly flamable oxidiser, heavy moving parts that need maintenance, less effective in warm seas, 3rd party contractual issues, technical advances including LIBs partly bypassing AIP, have persuaded the Japanese Navy that AIP is not worth including in their future Soryus. The 200 tons might be better used for more diesel or batteries. Australia, Malaysia and Indonesia have not used AIP in their submarines due to AIP's marginal worth.

More on LIBs

Returning to LIBs - LIBs are reputedly lighter (than the traditional lead acid batteries they are replacing). LIBs carry more charge (greater energy density) translating into more speed or a longer period the submarine can submerge. LIBs should take less time to recharge, so there is less "indiscretion" time when the submarine has to snorting-snorkel near the surface. The increased capability of anti-submarine sensors, including those mounted on satellites and UAVs, mean that  submarines in near surface snorting mode are becoming more vulnerable.

LIBs involve potential technical risks. LIBs may be more prone to catch fire (based on experience with the 787 aircraft LIBs). LIB use for submarines may be becoming safer than aircraft use due to heavier submarine LIBs with the extra mass more able to absorb heat. This should mean submarine LIBs do not get as hot as aircraft LIBs - hence submarine LIBs should be less prone to catching fire.
A second major difference is that aircraft LIBs have (or had) no dedicated fire suppressant systems while such systems should be built around submarine LIBs. Overall the experience of ironing out bugs on aircraft and car LIBs is valuable in the development of submarine LIBs.

New technology always involves some uncertainty. Lead acid batteries for submarine have a record of use since 1888 (hence their characteristics are more predictable) while LIBs probably have no operational use on submarines. The replacement cycle for submarine LIBs is also hard to predict.

Before Australia operates Soryus Japanese Navy Soryus will most probably have had several years experiece of using LIBs - hopefully ironing out all the bugs. Australia may be better placed if there is an option of deciding on LIBs or lead acid batteries before Soryus earmarked for Australia begin to be built.

Germany, and France are also developing and beginning to offer LIBs for submarine use. Presumably Sweden, South Korea and the US (for backup batteries) are also developing submarine LIBs.

Life Cyle Differences

One additional issue is that the Japanese Navy has been running its submarines with the assumption the service life is 15-20 years while Australia assumes submarines should be in service for at least 30 yours. This may or may not be a problem. After 15-20 years moving parts may or may not start to wear out. This may be most significant in the submarine's diesel engines and the very large electrical motor. Changing engines-motors is very heavy maintenance involving cutting into the submarine hull. This might only be possible in Japan for the Soryu? Maintenance realities may or may not be a problem.

If all these issues prove too hard over the next 5 years there are submarines operated by Germany,  France and Sweden (all of around 2,000+ tons surfaced) that may be adequate for what Australia needs. This is particularly under limitations in funds for purchase and crew availability problems.

Pete

Comments on What Appears to be a Soryu Sale Press Relaease

The Soryu lobby (Japan of course but to an extent the US) issued what amounts to a Soryu Press Release (see below) on January 20, 2015. This was possibly to influence any statements Australian Defence Minister Kevin Andrews was expected to make during his visit to the Australian Submarine Corporations (ASC) submarine facility in Adelaide on January 22, 2015. As it turns out Andrews said little memorable other than the Australian Government had made no submarine selection decision.

COMMENT

After some positive feedback (with pertinent information) from Japanese commenters I'm toning down the title and some of my comments in the post. The "Soryu Press Release" is a Japan Times article of January 20, 2015. The article/Press Release:

- would have been mostly written by and cleared by the Japan Ministry of Defence.
- there is the exaggerated implication that Australia is privileged to be allowed to receive such a Japanese technical achievement.
-  but nevertheless Japan may not carry out the standard industrial task of revealing to Australia key technical secrets. This withholding of secrets may include those behind the Soryu's  potentially dangerous Lithium-ion battery (LIB) see "Japan...has yet to decide which secrets to share".
- that the US is in favour of the Soryu export to Australia for the US's own strategic and financial reasons
- makes the standard claim that is Australia is happy to work in strategic alliance with Japan and the US over Japan's interest in contested islands in the East China and South China Seas. Australia has been very cautious in not being drawn into Japan-China cofrontations in those seas
- basically Japan's Soryu pitch is that Australia is strategically obligated to buy the Soryu..

There is some recognition by Japanese commentators that Australia will incur major economic costs by sacrificing much of its ship-submarine building industry. However these  commentators under-rate the opposition and rift in Prime Minister Abbott's own governing Party with increasing feeling against submarines being built in Japan. Instead there is increasing support across the` political spectrum and within Australia's Navy favouring construction of the submarines in Australia.

The risks for Australia of being Japan's first major defence customer are ignored.

An incentive for Japan is, of course, is Australia's money to offset Soryu 2 (Lithium battery) development costs.

 The article/pitch/Press Release is below - with string  http://www.japantimes.co.jp/news/2015/01/18/national/stealth-tech-no-given-in-japanese-sub-deal/#.VL3UDUeUen8 :

"Stealth tech no given in Japanese sub deal

BY REIJI YOSHIDA

Retired Vice Admiral Masao Kobayashi commanded Japan’s submarine fleet from 2007 to 2009. In a recent interview in Tokyo with The Japan Times, when asked to explain one of the country’s most tightly guarded military secrets, he seemed reflective.

Kobayashi pointed to the ceiling lights in the quiet interview room and said: “Take those fluorescent lights, for example. Any fluorescent light generates sound.”

Other than our voices, there were no other sounds in the room.

“Fluorescent lights generate extremely small vibrations. We take anti-vibration measures for every single light in a submarine,” he said.

Japan’s engineers have painstakingly worked to minimize the vibrations given off by the multitude of components in submarines to prevent even those undetectable by the human ear from being picked up by the super-sensitive sonars of enemy subs and sonobuoys from anti-submarine aircraft, Kobayashi said.

Noisy components include fans, pumps, motors and fluorescent lights. Some are carefully muted with vibration-damping rubber, he said.

“The quiet submarines we have today are the result of numerous long, patient efforts,” Kobayashi said.

The Maritime Self-Defense Force’s submarines are not nuclear-powered but have a reputation for being ultra-quiet.

Now Australia, seeking to build a new fleet of large, long-range submarines, seems keen on acquiring Japan’s latest Soryu-class subs, or at least their technology.

If the deal goes through, the top-secret submarines will become the first major pieces of military hardware Japan has authorized for export since the administration of Prime Minister Shinzo Abe lifted the decades-long blanket ban on arms sales last year.

Vice Adm. Robert Thomas, commander of the U.S. Navy’s 7th Fleet, reportedly said Oct. 24 in Tokyo that then-Australian Defense Minister David Johnston was very interested in Japan’s Soryu-class subs.

“I talked to him about it four years ago and I said: ‘You want to find the finest diesel-electric submarine made on the planet — it’s made at Kobe works in Japan,’ Thomas was quoted as saying by Bloomberg News.

The U.S., which has close but separate security pacts with Japan and Australia, probably wants Australia to buy Japanese submarines because it would greatly strengthen their strategic military ties, Kobayashi said.

Deeper Japan-Australia military cooperation would help ease the heavy burden on the U.S. fleet, which is busy decommissioning many of the nuclear-powered attack submarines it built during the Cold War, he said.

“The U.S. rapidly built many Los Angeles-class nuclear submarines during the Cold War. Many of them are being decommissioned now,” Kobayashi said.

“I think the U.S. wants to create a strategic triangle of Japan, Australia and the United States. That’s probably a factor behind” the apparent U.S. nod to Australia’s proposal to Japan, he added.

Japanese defense officials are thought to be pleased for the same reason Washington is. They want to deepen strategic military ties with Australia.

“Australia would make a good partner for cooperation. There are no major diplomatic problems between the two countries other than whaling,” a senior Defense Ministry official said on condition anonymity. Australia opposes Japan’s annual whaling expeditions.

Japan has just started receiving the submarine specifications sought by Australia but has yet to decide which secrets to share, two senior defense officials said.

Japan soon plans to use lithium-ion batteries to drive the motors in its latest Soryu sub, making them even quieter. Australia is believed to be interested in this advance, the officials said.

But advanced lithium-ion batteries are one of Japan’s top military secrets, one warned.

“(Exporting) them would be a rather sensitive issue. We’d need to study if it’s really appropriate for an outside party (to have that technology),” the Defense Ministry official said.

In Australia meanwhile, opposition lawmakers and trade unions are strongly opposed to procuring Japanese submarines because it could considerably undermine the domestic defense industry and reduce jobs in South Australia.

Joint development might be an option, the two Japanese officials said, noting that nothing concrete has been officially proposed.

Teruhiko Fukushima, a professor at the National Defense Academy in Yokosuka, Kanagawa Prefecture, who is an expert on Australia, said Prime Minister Tony Abbott seems eager to procure the subs to bolster Canberra’s military ties with Japan and the United States.

“Abbott should be considering a Japan-U.S.-Australian alliance as a kind of insurance” against the recent rise of China’s powerful military, Fukushima said.

“The introduction of Soryu-class submarines would be a plus to strengthen that alliance,” he added.

“If the Abbott administration survives the next election and wins a second term, there will be a greater chance that Soryu-class submarines will be introduced in Australia,” he said.

Last June, Australia and Japan conducted “two-plus-two” talks between their foreign and defense ministers.

In the joint statement that followed, Australia expressed “strong opposition to the use of force or coercion to unilaterally alter the status quo in the East China Sea and the South China Sea,” an apparent warning to China to not aggressively press its territorial claims in those areas, which include the Japan-controlled Senkaku Islands, which China and Taiwan also claim. China calls the uninhabited islets Diaoyu and Taiwan calls them Tiaoyutai.

Fukushima also said that on Nov. 26, 2013, only three days after Beijing declared the establishment of an air defense identification zone over the East China Sea that included the Senkakus, the Abbott administration summoned the Chinese ambassador in Canberra to express its concerns after the ADIZ drew strong protests from Tokyo and Washington.

“There is no doubt Abbott puts great emphasis on the relationship shared by Japan, the U.S. and Australia,” Fukushima said.

But he also noted that China is Australia’s No. 1 trade partner and that the public would never approve of political actions that could seriously damage those economic ties.

“The best way for Abbott is to strengthen the Japan-U.S.-Australian relationship while maintaining good economic ties with China at the same time. Australia would never turn its back on the Chinese market,” he said." ENDS

Pete