The political and strategic ramifications of the AUKUS pact involving the US, UK and Australia continue to reverberate, but the details of how Australia will acquire nuclear-powered submarines (SSNs) have often been overlooked. There are daunting technical, industrial and financial challenges on the long road to joining that club.

Even the acquisition of conventional submarines isn’t easy and projects completed on time and budget are rare. Nuclear propulsion adds another layer of complexity and cost, and the engineering challenge has been described as more demanding than building the space shuttle. There are good reasons why SSN ownership is limited to a small group of elite nations—the US, Russia, China, the UK, France and India. (With considerable French assistance, Brazil is on track to have its first nuclear boat in the late 2020s.)

The Royal Australian Navy’s conclusion that it needs SSNs makes complete sense. The distance from its bases to the likely areas of operation are considerable and even the best conventionally powered boat will take many more days to get into theatre. It’s around 5,500 kilometres from the RAN base near Perth to the South China Sea. The RAN will need to compete with China’s SSNs, which may not currently be of the quality of Western equivalents but progress with the surface fleet indicates that they’re likely to grow rapidly in quality and numbers over the next decade.

Some commentators suggest that Australia’s first boats at least could be bought off UK or US production lines. Alternatively, old or ‘surplus’ submarines could be leased until new vessels are available. These assumptions are at odds with the US Navy’s and Royal Navy’s struggles with bringing new boats into service and maintaining ageing vessels.

HMS Astute arrived at HMAS Stirling near Perth in October, the first of its class to berth in Australia. It was visited by the RAN chief, Vice Admiral Mike Noonan, and other dignitaries. There’s been talk of eventually operating an Astute-class sub from Australia when appropriate support facilities have been developed, but the tiny RN submarine force already has its hands full in the Euro-Atlantic.

Defence Minister Peter Dutton has said ^[1] the RAN is considering leasing boats from the USN or RN but that’s far from a certainty. The RN is already severely short of active boats—nominally down to six SSNs, and able to field two or three on a good day. The USN is trying to maintain its existing force, struggling to build enough new Virginia-class SSNs while its Los Angeles-class boats are phased out. However supportive of Australia the UK may be, it has no suitable boats available to lease. The US has a far bigger fleet with 28 Los Angeles boats still active, but its force is already overcommitted and Washington is unlikely to offer anything, except perhaps a recently retired boat as a static training vessel.

Neither the US nor UK keeps submarines ‘in reserve’. The UK has already expensively extended the 1980s-vintage Trafalgar-class boats well past their 30th birthdays. None of the growing collection of decommissioned hulks could be returned to service with all the funds and will in the world. Their nuclear fuel is spent, and they would need colossally expensive refits and refuelling. More critically, submarines have finite hull lives. Every dive fatigues the pressure hull and pipework to a point where safe diving becomes severely restricted or the boat becomes unseaworthy. Older boats become increasingly hard to maintain and struggle to retain their all-important minimal acoustic signature.

The US has a more effective submarine dismantling program than the UK and its LA-class boats are gradually being scrapped. The inactive boats that remain intact are equally tired and some were withdrawn from service prematurely to avoid the cost of mid-life refuelling. There’s a slim chance that one or two of these boats could see further service with the RAN but only at enormous expense, and refitting them would put more strain on overburdened US industrial capacity.

RAN Vice Admiral Jonathan Mead has said, ‘It is our intention that when we start the build program, the design will be mature and there will be a production run already in existence.’

Some suggest ^[2] the Astute’s the best solution, optimistically proposing that the first couple be built in the UK before technology transfer enables the remaining six to be made in Australia. In many ways, the Astute would appear to be ideal—it’s already in production, it would be far cheaper than the US options with smaller crews, and the vessels are highly rated. Unfortunately, there are almost insurmountable obstacles to the class ever numbering more than seven.

In the UK, completion of the remaining Astute-class boats is finely balanced with the construction of the Dreadnought-class ballistic missile submarines (SSBNs) and there’s not space in the shipyard or skilled people available to add additional boats. (If it were possible, then many would argue that the RN should buy more Astutes as priority one.)

BAE Systems and the specialist UK submarine supply chain broadly welcome the opportunity but are  still in the early stages of exploring how they can help Australia. People didn’t prepare for nuclear submarine exports and AUKUS was a bolt from the blue.

Assuming money was no object, new engineers could be recruited and the Barrow facilities could be enlarged, the project would still be in trouble because the Astute’s PWR-2 reactor no longer meets modern safety benchmarks and production has almost ceased. Reactors require very long lead times and reactor assembly begins well ahead of cutting steel for the hull. The RR nuclear manufacturing facility in Derby is being comprehensively rebuilt and production is now focused on the larger PWR-3 for Dreadnoughts and eventually the SSNR, which it’s believed will follow the Astute. (Design work on PWR-3 began as long ago as 2006.)

Even if additional PWR-2 reactors could be acquired and the Astute boats could be constructed in Australia, they’d be semi-obsolete when they began to arrive in service by the late 2030s. The Astute is among the world’s best SSNs and will continue to be the gold standard in stealth terms for another decade at least. However, the design, from the early 1990s, is likely to be superseded by the 2040s. The next generation of SSNs will need much greater capacity than the Astute to launch, recover and communicate with the unmanned underwater vehicles that will become an ever-growing part of the undersea battle.

The original Virginia design (Block I) is older than the Astute but has benefited from an iterative development program, with 34 boats built or on order to date. Among many improvements, from the Block III boats onwards, they have been fitted with two Virginia payload tubes (VPTs), vertical launch cells which can each hold six Tomahawk and other missiles, and, potentially, uncrewed vehicles. The latest Block IV boats have been stretched by 25 metres to include another four seven-cell VPTs.

About two Virginias are produced per year, although last year the USN announced a plan for an SSN force of 72–78 by the 2040s, which would require production to increase in the 2030s to about three per year, concurrent with building the very large Columbia-class SSBNs.

Although the USN benefits from an established design and an industrial base that’s vastly more efficient than that of the RN, the yards and supply chain will need to expand significantly to fulfil the ambitious plans to grow the USN fleet. A recent report to Congress ^[3] noted that ‘observers have expressed concern about the industrial base’s capacity for executing such a workload without encountering bottlenecks or other production problems in one or both of these programs’.

The USN also has issues maintaining its existing submarines. The report says: ‘SSNs have had their deployments delayed due to maintenance backlogs at the Navy’s four government-operated naval shipyards which are the primary facilities for conducting depot-level maintenance work. Delays in deploying SSNs can put added operational pressure on other SSNs that are available for deployment.’

The latest Virginias have considerably greater land attack capability than the Astute and are more modern. But despite the economies of scale, they come with a significantly bigger price tag and have a crew of 132. The RAN is already short of people for its six Collins-class boats, which have just 58 crew. If the RAN were to acquire eight Virginia Block IV or equivalent, it would need a major recruitment and training effort. It’s estimated that the RAN needs 2,300 trained submariners. Achieving that number will take years and must allow for a typical wastage rate of about 30% of recruits dropping out or failing to qualify.

For the more senior roles, the process is even more demanding. It takes at least 16 years ^[4] from initial entry to qualify as a nuclear submarine’s engineering officer. The RN and USN can certainly assist with submariner development and provide hands-on opportunities at sea. Both navies have very similar reactor technology and operating procedures, and RAN personnel would gain valuable experience on exchange with either navy, whatever SSN Australia selects.

Very little can be said with certainty about the US and UK future designs which are in the early concept phases. Both will probably feature aspects ^[5] of the Columbia and Dreadnought SSBNs, be bigger than the boats they replace, and have x-tail hydroplane arrangements and turbo-electric drive instead of direct drive from their steam turbines.

If the RAN waits until at least 2040 for SSNs, partnering with one of these programs would make sense. The RAN would have input into the design from the outset and development costs could be shared along with economies of scale in the supply chain. The British boat will almost certainly be more affordable and there’s already synergy between BAE and Australian industry with the Hunter-class frigate. The US SSNX would be more costly but might be more attractive since US combat systems and weapons are used on the Collins-class boats. A US solution would also benefit from the relative proximity of Guam and Japan, where they could share support facilities.

When the AUKUS announcement was made, the Australian government promised to acquire at least eight nuclear submarines to be built by ASC in South Australia. There’s limited submarine building experience left at ASC since the Collins boats were completed in the early 2000s. The deal with the French to build Attack-class boats included technology transfer to regenerate the skills base. Whatever SSN design is selected, greater assistance will be needed from the UK or US. With limited nuclear infrastructure, Australia is unlikely to be able to enrich uranium to fuel the reactors. It’s likely that the reactor compartments will have to be imported pre-fabricated from the US or UK. The entire submarine enterprise will require Australia to establish ^[6] a new safety and regulatory framework.

Australia will need to recruit, train and educate some of its brightest and best to build up a significant cadre of civilian engineers for construction and shoreside support tasks. Secondment of personnel to gain experience with BAE or with General Dynamics Electric Boat and Huntington Ingalls Industries should start as soon as possible. Personnel allocation must be carefully coordinated across the three nations. Poaching scarce technical staff from the UK or US with offers of well-paid jobs in sunny Australia would quickly cause friction and undermine AUKUS.

Besides the high-profile investment in the main construction facility, Australia will have to spend substantial sums on supporting infrastructure, including dry docks, jetties, weapons handling and storage facilities, and personnel accommodation. The 10 UK submarines require three nuclear-certified dry docks, two at Devonport and a covered ship lift at Faslane. This doesn’t include the construction facilities at Barrow and two docks dedicated to the disposal of old boats. Nuclear-certified docks and jetties are expensively overengineered to withstand once-in-a-lifetime seismic, tidal or storm events and have multiple redundancies in power and water supplies.

The UK demonstrated that such infrastructure can be created from scratch quickly during the 1960s Polaris project, but such works are major undertakings, costly and require highly competent management.

Former prime minister Malcolm Turnbull said of the AUKUS deal: ‘There is no design, no costing, no contract. The only certainty is that we won’t have new submarines for 20 years, and their cost will be a lot more than the French subs.’ This is broadly correct. The eventual acquisition of SSNs is possible, but there are many potential showstoppers. The single biggest factor will probably be just how much the US government is willing to prioritise industrial assistance to the RAN at the expense of growing and supporting its own submarine fleet. The US has only ever exported nuclear technologies to Britain and must amend its laws to do the same for Australia.

A couple of elderly SSNs might be available for lease in the 2030s, but realistically it will be the 2040s before the RAN has sufficient SSNs to exert a strategic effect. The geopolitical situation could be vastly different then, and growing Chinese power and influence won’t wait for others to attain parity. The Australian public will also have to buy in to a project needing political commitment for decades and the RAN will have to lean heavily on allies and provide an enormous budget to cover the true financial costs of nuclear ownership.