Collins subs outstanding problems fixed

ASC managing director Steve Ludlam says principal remaining problems with Collins subs, including unreliable engines, have been solved at last.

After more than a decade of controversy, shipbuilder ASC says it has finally solved outstanding problems with the navy's six Collins submarines.

Steve Ludlam, managing director of ASC, formerly the Australian Submarine Corporation, said he believed Collins' much publicised problems were now behind them.

"We are getting a much higher level of availability. We are getting good reliability at sea," he told AAP.

"They are very complex machines and we can't guarantee that everything will run perfectly all the time, but the principal areas of concern have now been solved."

Collins submarines had a range of problems from the outset, including excessive noise and an unreliable computerised combat system, prompting an extended and costly remediation program.

But reliability problems persisted with Collins' diesel-electric propulsion system. Each boat has three large diesel engines, three generators and an electric motors. Each has had problems.

Mr Ludlam said they had been able to work out how to reduce diesel engine vibration and a reliable engine-start system.

"Our engineer team here at ASC, who are some of the world's best, have been able to figure that through," he said.

"We worked with an international diesel specialist company to make sure we were getting the right answers."

Neither were generators problem-free.

"We found a method of rewinding those generators. They are much more reliable now. Progressively we are replacing generators on the submarines," he said.

Similarly, the large electric motor experienced a particular issue where the windings had relaxed.

"Working with the DSTO (Defence Science and Technology Organisation) and DMO (Defence Materiel Organisation) we have figured out to fix that and progressively we are fitting that fix to each of the submarines as they come in for various levels of maintenance," he said.

ASC is now working on two of the Collins subs.

HMAS Collins, the first of the Collins boats has been undergoing full cycle docking, a regular and comprehensive refurbishment, since last August. That should run for two years.

HMAS Rankin, the youngest of the Collins boats, has been out of the water for six years and mothballed for much of that time. Its full cycle docking started in 2011 and it should be back in the water next year.