Since the announcement that Australia will build nuclear-powered submarines on September 15, speculation has been rife as to which submarines are being considered. The partners, Australian-United Kingdom-United States (AUKUS), have given themselves 18 months to come up with a plan.
Few details have trickled out since the joint announcement. So the question remains, which type of nuclear submarine will Australia get? Stepping back, let’s explore the options.
We can be confident that the submarine will essentially be British or American. There are five main options to consider.
The first two are the U.S. Navy and Royal Navy’s existing designs, the (1) Virginia Class and (2) Astute Class. Then there are the corresponding next generation attack submarine programs, the (3) SSN(X) and (4) SSN(R). And lastly, (5) a whole new design but leveraging technology from US and UK.
More ambitiously it might be a substantially indigenous design with only minimal input from US or UK. Or perhaps the next generation submarine projects of all three countries will be combined into a single type, to be built in all three countries. These possibilities feel less likely at this point.
Other honorable mentions could include a fourth country’s design such as France or India. Or China or Russia (as if!). Or only second-hand submarines. Maybe even older ballistic missile types (SSBNs) repurposed as attack submarines. None of these solutions really ring true with the original announcement and are not being explored any further in this article.
1. Virginia Class – America’s trusted attack submarine
The first type which comes to many lips is the U.S. Navy’s Virginia Class. No one doubts its capabilities, and commonality with the US Navy would yield training and support benefits. It uses US weapons systems, which the RAN already has in its inventory, such as the Mk.48 ADCAP torpedo.
And its vertical launch system (VLS) gives compatibility with Tomahawk cruise missiles. Australia is already set to acquire these, but for the surface fleet. It would be natural to put them aboard the Virginias too.
In fact the Virginias make less sense without Tomahawk or some other missile to put into the VLS. The current Block-IV Virginias have 12 vertical missiles, and the Block-V will have 40. The Block-V’s capacity seems overkill, so a Block-IV appears more likely. Although benefiting from some advancements from later blocks.
A challenge with the Virginia Class could be the cost of setting up Australian production. Although there is speculation that Australia could acquire the boats straight off US production lines, this isn’t in the spirit of the announcement. And US yards have years of Virginia class construction ahead. So a new set of tooling would need to be made to set up a new production line in Australia.
2. Astute Class – the British option
The Royal Navy’s Astute class is broadly equivalent to the Virginia Class. Similar in overall size and capability, it may have a couple of advantages which might attract the RAN. The first is that, unlike with the Virginias, tooling might already be available. The last of the Royal Navy’s 7 boats, HMS Agincourt, is expected to be floated in the next couple of years. This might free up the tooling which could be shipped to Australia, representing a significant cost and time saving.
Another potential strength of the Astute is that it has a smaller crew. Still much larger than the current Collins Class, that is to be expected for a long-range nuclear boat, but smaller than the Virginia’s. The Astute is crewed by 98-109 people, while the Virginias normally have around 135. The Collin’s for comparison has 58, so we are talking about at least doubling the submariner needs.
A challenge for the Astute option might be the nuclear reactor. The current PWR2 reactor is no longer in production. Potentially the newer PWR3, or a US reactor, could be fitted, but this would complicate things.
At any rate an Australian Astute Class boat would likely have some modifications to suit RAN needs. We can speculate that these might include an alternative sonar and possibly US weapons to keep continuity with the Collins. But it is anyway compatible with tube-launched Tomahawks.
Some technologies for the next generation SSN(R) design could also be incorporated, which brings us to the next two options.
3 & 4. Next Generation Attack Submarines
Joining one of the existing next-generation projects, SSN(X) and SSN(R), could allow Australia to enter the nuclear submarine club at the very top. Advances in propulsion, sonar, stealth, quantum computing, integration with uncrewed underwater vehicles and so on, would be baked in.
It would also allow the other party, US or UK, to more directly share the development costs, which might be more attractive. The challenge of course will be timelines. Australia needs new submarines to be in the water in 2040s, and the current Collins Class will only last until around 2048. Both the SSN(X) and SSN(R) are expected to start getting wet in the 2030s. But timelines on these types of project are always likely subject to skepticism. Especially if another navy joins the party and adds requirements.
One key technology which hasn’t been discussed much is hypersonic weapons. The US Navy appears to be going that way, and possibly the Royal Navy too. If the RAN want to future-proof, them might consider this variable. Which boat lines them up best for future weapons?
The next-generation boats are also expected to be larger than the current types. Partly this will be due to improved stealth with new propulsion technologies. But in the submarine game, larger normally means more expensive.
5. A truly Australian design
By going their own way, Australia could build a submarine tailored to their needs while still leveraging key British or American technologies. The result might be a smaller and cheaper boat, yet still giving the RAN the main advantages of nuclear power.
Of course this option takes the biggest risk in design terms, even if the end product is more modest. In particular, it would place a strain on the limited pool of naval architects and engineers needed to design it. This is actually true of all the options above, but more so with this one. Would the Australian program be poaching designers from the SSN(X) and SSN(R) programs?
Whatever the options being considered, building nuclear submarines in Australia will take decades. In the meantime the current Collins Class diesel-electric submarines will be upgraded to keep them operable.
The RAN might also consider leasing US Navy or Royal Navy boats. Several Los Angeles Class and Trafalgar Class boats are due for retirement in the coming years. These could be extended for a few years until the fuel runs out. Maybe even moored in port as stationary training platforms. In addition to these types of progressive steps, RAN submariners could become a common sight aboard British and American boats. And Australian engineers too.
Stepping back again, it is a massive undertaking for the RAN. But they are lucky to have the AUKUS partnership which opens the door to these illusive technologies.
The biggest threat may be in the process. The boats are all excellent, there is almost no bad option. But an indecision or ambiguity could lead to delays.
And regardless of the RAN program, we may see more countries going for nuclear submarines. And China, the focus of the AUKUS submarine deal, won’t slow down to accommodate Australia’s challenges.