The company has not been asked to provide information on its current boats despite being due to start work on the first of two A26 submarines for the Swedish navy before the end of 2012. That vessel is due to be commissioned in 2018, a record time by Collins-class standards.

The head of Australia's future submarine program, Rear-Admiral Rowan Moffitt, said the company had been dropped from a list of four European companies being considered for a ''military off-the-shelf'' option because it did not have a new design in service.

Defence is to pay three other European manufacturers - Spain's Navantia, France's DCNS and Germany's HDW - up to $300,000 each for details on what would be needed to adapt their vessels to Australian requirements, what this would cost and what impact the changes would have on their performance.

Defence experts say while it would cost at least $36 billion to produce a locally designed Collins replacement, an off-the-shelf capability would come in at well under half that amount.

In the event an ''off-the-shelf'' design is chosen it would likely be built in Australia at ASC's Adelaide facility.

Admiral Moffitt said while a Rand Corporation study had identified significant gaps in Australia's submarine design capability, the construction side of the equation was much healthier.

''[And remember] when we built Collins, we had no submarine construction skills in Australia,'' he said.

Admiral Moffitt said his staff have just completed a future submarine submission that will be forwarded to the Defence Minister, Stephen Smith, in the immediate future.

Although Kockums, whose 2000 tonne A26 class submarine will have blue-water capability, air-independent propulsion, and stealth technology, has been overlooked, other unbuilt and untested designs are in the running.

Admiral Moffitt said Defence was keen to learn more about the HDW 216, a super-sized variant of the German company's proven 214 design apparently conceived with Australia's requirements in mind. ''It [the 216] is very much of interest to us,'' he said. ''It does reside in one of our design spaces.''

Defence is also engaged in preliminary talks with the Japanese over the possible acquisition of state-of-the-art conventional submarines designed and built by Kawasaki and Mitsubushi. ''The Japanese submarines are a very good product we understand,'' he said.

Admiral Moffitt, who was quizzed about the future submarine project at Senate estimates this week, said the timing of delivery depended on more than just how long it took to design, build and test them.

''Delivering the 12 submarines outlined in the 2009 defence white paper is a generational activity,'' he said. ''It will take a long time and this will include growing the submarine workforce.'' He said it took at least 15 years to develop a submarine commander or a submarine engineer - and that the process could not easily be accelerated.