Australia's AUKUS Submarine Deal Shifts to All Used Vessels

Under the initial AUKUS agreement, Australia was set to receive two used Virginia-class nuclear-powered submarines from the United States, plus one new model as early as 2032.

But the plan has changed and now all three submarines will be second-hand, a decision Defence Minister Richard Marles said would save "significant" amounts of money and simplify fleet training and maintenance.

The Virginia-class vessels are part of a stopgap phase to boost the Royal Australian Navy's capabilities until the first AUKUS-class nuclear-powered submarines start arriving from about 2042.

Some analysts have been critical of the pivot, questioning whether relying on used submarines would reduce Australia's naval capabilities.

But others say the older fleet could work in Australia's favour.

How old is old?

Under the original plan, the US was selling Australia two "used but refurbished" Block IV Virginia-class submarines.

The third was intended to be a newer Virginia-class model straight from the production line.

But now the purchase would be streamlined and all three would "be of the same type," Mr Marles said.

"I cannot overstate the significance of that, both in terms of the submariners who are operating them, but also the people who are working on them to sustain those submarines," he said.

Marcus Hellyer, head of research at defence think tank Strategic Analysis Australia, said there had been a lot of "hand wringing" about acquiring older vessels.

But the Block IV submarines only started entering service between 2020 and 2026, with the remainder of the fleet set to be finished by next year.

"These are the boats the US is currently finishing, so they're not old in a sense of old," Dr Hellyer told the ABC.

The average life span of the Block IV submarines is about 33 years.

The first one is expected to arrive in Australia in 2032, with the additional vessels being delivered at four-year intervals until 2038.

The first two boats would be refurbished ahead of delivery, with about 23 years of life remaining, according to the AUKUS plan outlined by the government in 2023.

"They will be 10 years old maybe, which for a boat with a 30 to 35-year life span, we're not talking about old clunkers that are at the end of their life," Dr Hellyer said.

What capabilities does Australia need?

Virginia-class submarines are the latest class of nuclear-powered fast attack submarines in service with the US Navy.

The Block IV models were developed to replace the aging Los Angeles-class submarines.

They were designed for a wide range of missions, including anti-submarine warfare, intelligence gathering and strike operations using Tomahawk cruise missiles.

The Block IV also has improved acoustic stealth capabilities, making them harder to detect by enemy forces.

"The Block IV is arguably the best submarine in the world right now," Jennifer Parker, maritime security expert at The Australian National University National Security College, said.

The third, new submarine Australia had planned to buy from the US was either going to be a Block V or Block VII Virginia-class.

A main feature of the Block V is the longer length, which increased the number of launch cells used for weapons such as Tomahawk cruise missiles.

"There is a big difference in terms of the land attack capability, because Block V has 40 cells against only 12," Dr Hellyer said.

But that was a capability Australia did not necessarily need.

He said it was more useful for America "because as we've seen, they just love launching lots of cruise missiles into countries they don't like".

Beyond attack capabilities, submarines are used for intelligence and reconnaissance, anti-submarine warfare and special forces insertion.

"The biggest tasks for Australian submarines … regardless of what type of submarine we're talking about, is submarine warfare," Dr Hellyer said.

"So to find and kill the other guys' submarines."

Ms Parker, who is a former naval officer, agreed that needing a submarine with a larger range of land attack missiles was not a priority for Australia.

"If I was actually looking at how we employ these submarines, I would be employing them predominantly in the Pacific and the Indian Ocean in an anti-surface and anti-submarine warfare role," she said.

"So to find and sink warships and for intelligence, surveillance and reconnaissance."

In 2023, the US commander of submarine forces, Vice Admiral Bill Houston, said the new Virginia-class submarines being sold to Australia would likely be the Block VII.

Ms Parker said not a lot was known about the model, except it did not have the additional payload length.

"That was almost a mythical submarine, the design of which doesn't exist and they haven't started building it," she said.

"We always thought that the third submarine would be a new build, but beyond that we never actually knew what capabilities it would have."

Timing could get risky

Until the AUKUS fleet arrives, Australia is extending the use of 30-year-old Collins-class submarines, keeping the six boats in the water for an extra 10 years.

"We had the prospect … of almost having four classes of submarines operating at the same time — the last of the Collins class, two in-service Virginias, a brand new Virginia, and a brand new SSN-AUKUS. That gets pretty complicated," Mr Marles said.

"What we will have here is a simpler pathway."

Ms Parker said it would be beneficial to operate three of the same Virginia-class submarines instead of bringing another model into the mix.

"When you look at operating the same type of boat with the same type of systems on board, that means you reduce the workforce needed for the training,"

The downside would be there are fewer years available to operate the second-hand fleet.

Ms Parker said that would only be an issue if there were significant delays to the delivery of the first SSN AUKUS-class submarines.

Australia is expected to be operating its first AUKUS-class submarine in the early 2040s, and then the plan is to deliver one every three years until the final three are completed in the 2060s.

"The first Virginia will probably retire in the early 50s and the next one in the mid-50s," Dr Hellyer said.

"We have to remember that in the big picture of AUKUS, the Virginias are only a kind of transition stage … they're not a long-term solution."