AUKUS ‘trilateral submarine’ surfaces as option

Speculation is mounting that Australia may opt for a next-generation British submarine with a US combat system and weapons, rather than an American boat.

Defence Minister Richard Marles. Picture: Getty Images

Speculation is mounting that Australia may opt for a next-generation British submarine with a US combat system and weapons, rather than an American boat, as our future nuclear-propelled sub.

Former submariner Peter Briggs told The Australian the yet-to-be-designed British submarine, dubbed SSN(R), was firming as the likely AUKUS boat because its smaller size and crew requirements were more appropriate for Australian needs. The US alternatives – the current Virginia-class or next-generation SSN(X) – would require much larger crews and be less suited to operating in the archipelagos to Australia’s north, the retired rear admiral said.

“You would get a smaller hunter-killer submarine as opposed to a big missile platform, which is what the Americans want,” he said. “Such a large submarine would have trouble even getting through the archipelago, let alone operating in it.

“And if it’s big, it takes a big crew. Every extra tonne of displacement adds to the cost of owning the thing.”

The speculation comes amid repeated hints from Richard Marles and UK Defence Secretary Ben Wallace that the AUKUS sub will be a “genuinely trilateral boat”.

Australia’s Collins-class boats currently have a crew of 58, compared to 143 for the US Virginia-class and 98 for Britain’s current Astute-class subs. “The smaller the crew size the better, as long as the submarine has the endurance,” Rear Admiral Briggs said.

He said a key advantage of the SSN(R) was that Australia would be an “equal partner” in the boat’s development, with influence over the final design, and would potentially end up with more of the submarines than the UK.

Australia would require a US combat system and weapons, while the US could also supply the boats’ reactors, Rear Admiral Briggs said, ensuring all three countries would share the design and construction effort.

The view is backed by renowned British think tank the International Institute for Strategic Studies, which recently issued a paper saying the “SSN(R) has been finding favour, and could potentially be developed further under AUKUS”.

“This may ultimately be the foundation for the plan that eventually breaks surface,” IISS senior fellow for naval forces Nick Childs wrote.

He said the UK’s ageing Astute-class nuclear-propelled sub appeared to have been “set aside” as a potential option by the Australian nuclear submarine taskforce, but choosing the SSN(R) would ensure economies of scale for the British sub program.

Mr Childs said the forecast cost of the US-developed SSN(X), estimated at $8bn to $10.4bn per boat, “would be tough for both Australia and the UK to swallow”.

He predicted a jointly produced SSN(R) “may involve producing parts of the early Australian boats in the UK”. But he said Australia would benefit from a joint stake in a shared submarine enterprise with the UK.

Defence Minister Richard Marles said on Monday an announcement on Australia’s preferred option was “not far off”, and would be a “genuine three-way collaboration” between Australia, the UK and US. “I think when you see what is ultimately unveiled, it is the three countries working really closely together,” he said.

Standing by Mr Marles in the UK last week, Mr Wallace said the AUKUS submarines would be a “joint endeavour”. “Whether that is the sharing of technology and the understanding of how to do it, the sharing of the build, or the sharing of the design – whatever option is chosen by Australia, it will be collaborative,” he said.