Posted on 10/20/2014 7:51:00 AM PDT by sukhoi-30mki
JAPAN is preparing to change the sub-surface propulsion system for its Soryu submarines, dumping German and Swedish technology in a move that could clear a potential barrier to Australia purchasing the Japanese boats.
Tokyo’s plans to switch from the Kockums propulsion system to specially developed lithium ion batteries eliminates the potential embarrassment for Australia in rejecting German and Swedish bids in favour of using a sub that is powered by their intellectual property. The Kockums air-independent propulsion (AIP) system was designed in Sweden but licensed to Kawasaki Heavy Industries to incorporate into the Soryu class to power the subs on extended dives when oxygen supplies are limited.
Retired vice-admiral Yoji Koda, a defence scholar and former fleet commander of the Japanese navy, said the technology arm of the Japanese Maritime Self Defence Forces had worked for five years to develop an alternative lithium ion battery.
“They have strong confidence that the performance of the lithium ion batteries is good enough to replace the AIP,’’ Vice-Admiral Koda told The Australian.
Reports from Japan say the batteries would be built by GS Yuasa, the supplier of the batteries that some have linked with fires in the Boeing 787 Dreamliner aircraft. Japanese sources said defence authorities were convinced fire risks had been eliminated and the batteries would offer better speed and endurance than the AIP and lead acid batteries.
The JMSDF has confirmed the improved batteries will be incorporated into the next four Soryu-class submarines to be produced and it is believed Australian defence officials are aware of the change.
The Soryu class has been touted as the leading contender in the race to replace the Collins-class fleet, but sources say an update to the class is imminent and Australia — if it chooses to go with Japan — may actually purchase the next-generation large submarine, which would be based on the existing Soryu class but incorporate some improvements.
Germany has stepped up its campaign to trump Tokyo in the contest to build Australia’s next generation of submarines, saying that — in contrast to Japan — it has a proven track-record of exporting submarines to the world. Dieter Rottsieper, deputy chairman of German submarine builder ThyssenKrupp Marine Systems, recently met senior officials from the Defence Materiel Organisation to discuss Germany’s desire to bid for the lucrative contract.
Germany wants the Abbott government to have an international competition to supply the new submarines rather than simply award the $20 billion-plus contract to Japan, which has emerged in recent months as the government’s preferred partner.
The government is soon expected to announce a formal competition process to examine all international options, although Defence Minister David Johnston has previously described the Soryu as the best conventional submarine available.
“We would welcome an open competition,” Mr Rottsieper said. “We can offer our experience, we can offer 160 submarines that have been built over the last decades, we have an order book of more than 20 submarines ... currently all tailored to customer requirements (and) we are willing to take full responsibility for the price as well for the scheduling.”
The government believes that buying submarines that are designed and built by an experience submarine maker, then modified for Australian conditions, would be a cheaper and less risky option that building the entire fleet from scratch in Australia.
The government has indicated it favours buying a version of Japan’s Soryu-class submarine if Tokyo is willing to consider exporting all or part of its boats. Japan has never exported a submarine before.
ThyssenKrupp has said it could build 12 submarines for Australia at a fixed price of $20bn, cheaper than the Japanese option of $20bn-$25bn for eight boats. ThyssenKrupp is now the owner of the AIP system, having effectively acquired Kockums in 2005. Mr Rottsieper said his company had a long record of exporting submarines and it would be able to offer Australia a range of options that meant it could build as much or as little of the submarines in Australia as it wanted.
ThyssenKrupp is proposing building a 4000-tonne submarine, called a HWD-class 216, for Australia. Germany has not built a submarine that large before, however Mr Rottsieper said there would be “very low technical risk” in building the bigger boat because it would use the designs and materials of existing designs.
Too bad Japan can't say the same.
See I-400 class.
Yuasa Soryu!
Hint... stay the f... off both!!
This is just a PR stunt by the Japanese because they can’t provide an AIP. Current Lithium batteries can supply about 250 Wh/kg or 0.9 MJ/kg. There are some with more power but they burn like hell (see Boeing 787 fuel cell accidents).
The efficiency of a fuel cell is about 50 %.
Lower heating value for methanol is 19.9 MJ/kg.
The specific energy of methanol fuel cells is 10 times higher.
The energy density per volume seems to be 3 times higher for Li-batteries.
Li-batteries: 2.5 kg/l
Methanol: 0.8 kg/l
Methanol has about the same density like diesel fuel.
The problem for Li-batteries is the need for additional volume to compensate buoyancy for heavy installations. So the higher energy density is only fictional because your submarine has to weight about 1.025 kg/l to float.
How do you recharge lithium batteries at high seas? Long cable? Delivering methanol or LOX is no problem and already done by germane submarine tenders.
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