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Weighing up the options — Astute or Virginia Class?

Weighing up the options — Astute or Virginia Class?

Which nuclear-powered submarine capability would be best suited for the Royal Australian Navy?

Which nuclear-powered submarine capability would be best suited for the Royal Australian Navy?

A fleet of at least eight nuclear-powered submarines have been promised under the newly established AUKUS partnership between Australia, the UK and the US.

Minister for Defence Peter Dutton recently co-signed the Exchange of Naval Nuclear Propulsion Information Agreement — a legally-binding arrangement granting Australia access to advanced nuclear technology from partner states. 


The agreement establishes a framework for the disclosure and use of information related to naval nuclear propulsion, supporting the local construction of at least eight nuclear-powered submarines for the Royal Australian Navy.

However, Defence is yet to select a platform, with the UK’s Astute Class and the US’ Virginia Class submarines proposed as options.

The Commonwealth government has established a Nuclear-Powered Submarine Task Force, responsible for working with US and UK stakeholders over the next 18 months to determine a procurement pathway for Australia.

The group’s considerations are expected to include requirements for design, construction, maintenance, infrastructure, industry capacity, nuclear safety, environmental protection, crewing and training.

The Task Force will also advise on building timeframes, costs and supply needs.

Sam Goldsmith, director of Red Team Research and PhD on Australian defence industry innovation, weighs up the pros and cons of the Astute and Virginia Class submarines.

Goldsmith notes that both designs are fitted with nuclear reactors that never need refuelling; feature advanced pump-jet propulsors; support Tomahawk cruise missiles; and require Australia to “field a rigorous no-fail regulatory and safety regime”.

But he flags key differences which the Commonwealth government must consider during its 18-month review.

Design risk

Goldsmith observes that only the Virginia Class platform natively supports the RAN’s “presumably preferred” AN/BYG-1 combat system and Mk-48 torpedoes.

“Modifying the Astute to accommodate the RAN’s preferences could upset the fine-tuned space, weight, buoyancy, balance, power and cooling attributes, potentially triggering a cascade of unintended issues,” he writes.

“Modifying existing designs can cost hundreds of millions and take years: if it ain’t broke, don’t fix it.”

Alternatively, Goldsmith adds, the RAN could consider adopting the UK’s combat system and Spearfish torpedoes.


The analyst points out that both the Astute- and Virginia Class vessels are larger than the diesel-powered Collins Class fleet they’re expected to replace.

“Accommodating either of them may require significant upgrades to Australian assembly halls, slipways, dry docks and berths, and that won’t be cheap,” Goldsmith notes.

The Astute Class platform is a 97-metre-long, 7,800-tonne vessel, while Block V Virginias are 140.5 metres long and weigh approximately 10,364 tonnes.

In comparison, Collins Class boats are 77.8 metres long and 3,407 tonnes.

According to Goldsmith, this also presents crewing challenges, with the RAN already struggling to crew the Collins Class fleet, which requires approximately 60 personnel.

The Astute Class vessels are expected to require roughly 90 personnel, while the Virginia Class subs require a crew of around 130.


Additionally, the platforms vary in payload capacity, with Block V Virginias built with a significantly larger payload than the Astute vessels.

Goldsmith notes that the Virginia Class can also “ripple-fire dozens of Tomahawks” and potentially support future payloads.

“The British sub only supports torpedo-tube-launched weapons, with a magazine of 38 Spearfish torpedoes and Tomahawks,” he continues.

“The Virginia Block V carries around 65 weapons — 25 torpedo-tube-launched weapons, plus 12 Tomahawks in two payload tubes forward of the sail and 28 Tomahawks in four wide-diameter payload tubes aft of the sail.

“The Virginia’s wide-diameter payload tubes can also support future payloads such as autonomous vehicles, AIM-9X surface-to-air missiles and hypersonic boost-glide missiles.”


When considering the timeliness of delivery, Goldsmith expects the Virginia Class to edge ahead.

He writes that Australia could acquire an initial tranche of Virginia Block Vs off the shelf earlier than the Astute alternative to facilitate nuclear-safety and crew training, command courses and nuclear qualifications.

“Concurrently, a full production run of eight boats could take place in South Australia. A 2018 ASPI report determined that a ‘critical mass’ of 10 Australian SSNs would be required to sustain sufficient certified personnel, at sea and ashore,” he continues.

This plan would require USN support in terms of reactor supervision, at least in the early years, and the allocation of USN production slots to the RAN — but only if the US amended its priorities. The USN operates 19 Virginia Class boats with plans for 66.

“This concept could work with the Astute, but it would require the UK to keep building them beyond the planned seven boats and to delay production of its new Dreadnought Class submarines.”

Operation and sustainment

According to Goldsmith, the Virginia Class design may be easier to sustain and operate, given the resupply interoperability of the growing USN fleet.

“Research and development of leading-technology upgrades is always costly and justifying high R&D costs might be more difficult if there are fewer boats of a certain type,” he adds.

“If we assume that Australia eventually acquires eight to 10 SSNs, that would mean a total fleet of 17 Astutes versus 76 Virginias. In fact, the USN is already planning for a stealthier Virginia Block VI.”

Moreover, the Red Team Research director flags wartime resupply benefits, claiming that the Virginia would allow RAN and USN submarines to be resupplied with ordnance in Australia, Japan, Guam, Hawaii and San Diego.

However, Goldsmith acknowledges that as part of the AUKUS arrangement, a cache of Spearfish torpedoes could be stored at select RAN/USN facilities.

Workforce challenges

As noted, the Astute Class requires fewer crewed personnel than the Virginia Class.

Accordingly, Goldsmith notes that this could shorten the time required to train new Australian commanding officers and executive officers.

“RN COs and XOs are seaman officers who have completed the requisite nuclear systems course and are supported by specialist RN nuclear reactor engineers who don’t go on to command submarines. By contrast, USN COs and XOs are all nuclear reactor engineers who have stood watch over a submarine reactor at some point in their careers,” Goldsmith states.

“This difference is significant because it could take 15 years for an Australian nuclear engineer to gain sufficient at-sea experience to become an Australian SSN CO.”

Regulatory obstacles

Goldsmith warns there may be export-control challenges associated with selecting the Virginia Class boars, given the US State Department’s International Traffic in Arms Regulations (ITAR).

“Under ITAR, naturalised Australian citizens could be deemed dual nationals and might have difficulty in obtaining US government approval,” he writes.

“A person who is a dual national from a proscribed country would likely be rejected outright.

“Ignoring ITAR isn’t an option because penalties are severe and extraterritorial — for example, a US$1 million fine per breach and/or 10 years in jail and/or placement on US government denial lists.”

This could be particularly challenging for Australia, he adds, which is a nation of immigrants.

“By contrast, the UK government’s export controls might be more flexible concerning dual nationals and particularly naturalised Australian citizens,” he writes.

Final word

Irrespective of the ultimate choice, the program is set to be “incredibly technical, complex and difficult”.

“Even the most optimistic delivery timeline will take years, and it’s likely to be 15 years before qualified Australians are able to run the boats in a self-reliant manner,” Goldsmith observes.

“Getting this decision right will determine how difficult it is for Australia to operate, sustain and maintain its SSNs well beyond the 2060s.”

He concludes: “Few government decisions have so many long-term implications with so little margin for error. This is one of them.”

Get involved with the discussion and let us know your thoughts on Australia’s future role and position in the Indo-Pacific region and what you would like to see from Australia's political leaders in terms of partisan and bipartisan agenda setting in the comments section below, or get in touch with This email address is being protected from spambots. You need JavaScript enabled to view it., This email address is being protected from spambots. You need JavaScript enabled to view it., or at This email address is being protected from spambots. You need JavaScript enabled to view it..

Charbel Kadib

Charbel Kadib

News Editor – Defence and Security, Momentum Media

Prior to joining the defence and aerospace team in 2020, Charbel was news editor of The Adviser and Mortgage Business, where he covered developments in the banking and financial services sector for three years. Charbel has a keen interest in geopolitics and international relations, graduating from the University of Notre Dame with a double major in politics and journalism. Charbel has also completed internships with The Australian Department of Communications and the Arts and public relations agency Fifty Acres.

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