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Astute vs. Virginia: Which Nuclear Submarine Is Best for Australia?

Astute-class Submarine. Image: Creative Commons.

Picking the right design for the Royal Australian Navy’s nuclear-powered submarines is extraordinarily complex and difficult choices will need to be made. There are two contenders, the Royal Navy’s Astute-class submarine and the US Navy’s Virginia-class submarine, which refers to the ‘Block V’ variant of the boat.

Both designs are very good, and in some respects they’re equal. Both are fitted with reactors that never need refueling, both feature advanced pump-jet propulsors, both support Tomahawk cruise missiles and both will require Australia to field a rigorous no-fail regulatory and safety regime.

There are also numerous issues that will need to be considered by the government, including fleet size, submarine service life, Australian defense self-reliance, and Australian industry content.

This article highlights eight salient differences that will need consideration: design risk, size, crewing, payload, delivery, sustainment and operations, training regimes, and export controls.

First, the design risk. The Virginia natively supports the RAN’s presumably preferred AN/BYG-1 combat system and Mk-48 torpedoes, whereas the Astute doesn’t. 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. Modifying existing designs can cost hundreds of millions and take years: if it ain’t broke, don’t fix it. Alternatively, the RAN could accept the British combat system and Spearfish torpedoes.

Sizewise, both the Astute- and Virginia-class boats are larger than the conventionally powered Collins class. Accommodating either of them may require significant upgrades to Australian assembly halls, slipways, dry docks and berths, and that won’t be cheap. Astute-class vessels are 97 metres long and displace 7,800 tonnes, while Block V Virginias are 140.5 meters long and displace 10,364 tonnes. By contrast, Collins-class boats are 77.8 metres long and displace 3,407 tonnes.

A lower crew requirement is also desirable because finding crews of around 60 for Collins has been difficult. Astutes require a crew of around 90, whereas Virginias require a crew of around 130.

Block V Virginias have a significantly larger payload than the Astutes with the bonus ability to ripple-fire dozens of Tomahawks and support likely future payloads. The British sub only supports torpedo-tube-launched weapons, with a magazine of 38 Spearfish torpedoes and Tomahawks. 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.

If the US agreed, an initial batch of Virginia Block Vs could be acquired off the shelf and brought into Australian service relatively quickly, to facilitate RAN 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.

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.

The Virginia class might be easier to sustain and operate, given the USN’s rapidly expanding fleet and its resupply interoperability. 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. 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.

Wartime resupply is another issue for consideration: picking Virginia would allow RAN and USN submarines to be resupplied with ordnance in Australia, Japan, Guam, Hawaii and San Diego. However, the UK is also part of AUKUS, so holding a cache of Spearfish torpedoes at select RAN/USN facilities would be advantageous at any rate.

Choosing the Astute class could potentially shorten the time required to grow the pool of 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. 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.

The export-control factor is where choosing Virginia might run into serious problems. The US State Department’s International Traffic in Arms Regulations (ITAR) rigorously govern the transfer of all American military technology. Under ITAR, naturalized Australian citizens could be deemed dual nationals and might have difficulty in obtaining US government approval. 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. Ultimately, the ITAR dual-national restriction is problematic because Australia is a country of immigrants. By contrast, the UK government’s export controls might be more flexible concerning dual nationals and particularly naturalized Australian citizens.

Regardless of the viewing angle, picking the optimal nuclear-powered submarine for Australia is 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. Getting this decision right will determine how difficult it is for Australia to operate, sustain and maintain its SSNs well beyond the 2060s.

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

Sam Goldsmith is the director of Red Team Research, has a Ph.D. on Australian defense industry innovation, and has published through the US Naval War College. This first appeared in ASPIs the Strategist. 

Written By

Sam Goldsmith is the director of Red Team Research, has a PhD on Australian defence industry innovation and has published through the US Naval War College.



  1. Kevin

    November 28, 2021 at 1:51 am

    I’m surprised the author didn’t mention the most obvious consideration for aussie ssn which is cost.

  2. Gab

    November 28, 2021 at 3:16 am

    This article seems very pro the American Virginia class. But fails to mention the 4.4 billion aud price tag per boat compared to 2.6 Billion Aud for the Astute class.

  3. Bungy

    November 28, 2021 at 4:51 am

    The author clearly has no idea about submarines, building them and the costs. Dear, dear dear.

  4. Leslie Leveson

    November 28, 2021 at 2:48 pm

    Both boats have proved design capabilities and tech.The comparison is crew compliment and perhaps Astue build in Australia and the U S A now moving its production to another class of boat.This will free up boats that Australia could operate
    This will upset the Chinese dragon and not forgetting the Russian bear may deter from having a snoopy around the oz Australian coast.

  5. M

    November 28, 2021 at 4:07 pm

    The Astute class can also travel at 30 knots submerged compared to the Virginia class at 25 knots, so much quicker to get to it’s patrol area and back.

  6. Scott

    December 1, 2021 at 6:17 pm

    Purchase price of the submarine is actually a second order issue. The Collins Class cost us >$200million per year each to operate and crew. Astutes of Virginias will cost more. The key questions are time to build, support, and ability to crew. For these reasons I think we will get Astutes. Britain is nearing the end of its Astute program and could extend it with Aussie $. BAE is in both countries. The USN will not disrupt its Virginia/Columbia program. plus crew training of current RAN submariners is along British lines. The quickest, most painless transition would be to Astutes. They are both great subs; we should take whichever we can get in the water soonest.

  7. Adrian

    April 9, 2022 at 5:43 am

    The Astute class are true Hunter killer subs with land attack a secondary mission, the Astutes are arguably stealthier and are faster. The Virginia’s are Jack of all trades, master of none, they are expensive, have large crew requirements, will require larger berths (which Australia is yet to build), are likely to be more expensive to maintain and don’t really fit the mission profile of what Australia is seeking, Australia is trying to give China a massive headache in the south China sea, not launch tomahawks at them. I don’t really think it matters too much about US combat systems, the astute combat systems and spearfish torpedoes are second to none. This article describes an exercise between an Astute and Virginia class.–2

    ‘Our sonar is fantastic and I have never before experienced holding a submarine at the range we were holding USS New Mexico. The Americans were utterly taken aback, blown away with what they were seeing.’ – commander Iain Breckenridge

    I fear what Australia will purchase is a Frankensub. Astute with US combat systems that will ultimately be more expensive, less capable and years behind schedule. Never underestimate a government’s ability to fuck up military equipment procurement.

  8. Anthony

    April 9, 2022 at 11:03 pm

    I think the last line of Adrian’s comment hits the nail on the head; the ability of the Defence dept to stuff up procurement is legendary. Faster, stealthier, cheaper with smaller crews seems the logical way to go. Just watch what actually happens.

  9. Rob

    May 30, 2022 at 2:37 am

    The original Collins fleet cost us A$845 mill in 1993 money. Whatever the worth of the nuclear powered boats we dont need 8 of them.

    What we ought do is institute the LOTE program and buy four of the cheaper Astute built at Barrow, and build a new batch of Collins boats in supplement at Osborne with the LOTE modifications which by now would be prototyped on . Once the build is online we can axe the remainder of the LOTE project and forward that money to the new build 471.

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