The leaders of Australia, Britain and the US met today at a summit in San Diego to discuss the AUKUS pact. The centrepiece of the agreement is the deal to supply nuclear-powered submarines to the Royal Australian Navy (RAN). Here we examine the implications of the announcements and look at the future Anglo-Australian SSN(R) submarine project.
Australia will become a partner in the Royal Navy’s SSN(R) submarine project. This solution was always the most likely long-term answer, given the synergy between the respective timelines. In the medium term, the US has agreed to sell 3 or more second-hand Virginia-Class submarines that will not require nuclear-refuelling to the Australians and this will give them a stop-gap SSN capability by the 2030s and help them to gain operating experience. There is a plan to base one RN Astute class submarine and up to four Virginias at HMAS Stirling in Western Australia from 2027 to be named Submarine Rotational Force-West (SRF-West). For the RN, forward-deploying a boat down under will have a very significant impact on a force numbering just 7, although providing an attractive opportunity for British submariners that get very limited runs ashore.
The US has ambitions to expand its own SSN force (Virginia block V) as well as renew its SSNBs (Columbia class) but has limited industrial capacity. There would appear to be tension between the needs of the USN and the provision of boats to the RAN. In mitigation, Australia is set to make an immediate $1Billion investment in US submarine yards to help increase the output of new boats.
Respected independent USN analyst Craig Hooper says the US construction capacity is less of an issue compared to the neglect of submarine maintenance and support facilities and there is now such a backlog that it would actually be helpful to divert a few boats to the RAN. If the USN focussed on building new submarine tenders, reactivating at least two new maintenance yards and improving existing facilities it would actually increase overall SSN availability, even if total numbers are reduced slightly.
What is SSN(R)?
In simple terms, SSN is the standard naval classification for a nuclear-powered attack boat ie. “Submarine/Submersible Ship – Nuclear-powered” and the (R) stands for “Replacement”, ie. the next generation of SSNs to follow on from the Astute class. Construction work is now expected to begin on the first boat for the RN in parallel with the end of the Dreadnought programme. The first boat is expected to be delivered to the RN by the end of the 2030s and the first boat for the RAN built in Australia and delivered in the early 204os. With Australians now participating, the programme has assumed a global profile and hopefully, someone will soon come up with a more inspiring and memorable name than SSN-AUKUS. (“The Commonwealth class” or “Minogue class” perhaps?)
The Maritime Underwater Future Capability (MUFC) was the early name for the RN’s programme to consider replacements for the Astute class. The Concept Phase commenced in early 2018 but was suspended in May 2018 for two years. Work on the project resumed and very shortly after AUKUS was made public and in September 2021, the MoD awarded a £170 million contract split between BAE Systems and Rolls-Royce for initial design work on the new attack boats.
How undersea warfare will look in the 2040s and beyond is hard to predict. Despite the rapid growth of autonomous systems and potential improvements in detection technology, the promise of an entirely ‘transparent ocean’ may never be fulfilled. Leading nations continue to invest heavily in crewed submarines and AUKUS is another endorsement for their long-term future. Submarine design will continue to evolve but the ability to deploy, communicate with, and even recover, uncrewed submersibles to and from submarines will be of increasing importance.
Very little can be stated with certainty about SSN(R) at present and details of future submarine designs are highly classified. For reasons of cost and expediency SSN(R) is likely to have much in common with the preceding Dreadnought class SSBNs that are currently being built in Barrow. Assuming they will have the same PWR3 nuclear reactor, they would have the same pressure hull diameter as Dreadnought – around 12.8m. SSN(R) would therefore be substantially larger than Astute, although considerably shorter than Dreadnought. The additional space should provide for heavier armament and defensive countermeasures as well as better crew habitability. Larger boats with better access and internal volume eases the application of acoustic hygiene measures and are actually easier to construct and maintain in service although the capacity of available dry docks may be a constraining factor.
The key difference between Astute and SSN(R) is likely to be the inclusion of payload modules for vertical launch of missiles, medium-sized UUVs or seabed sensors. The Tomahawk missiles carried by RN submarines that are launched conventionally via torpedo tubes are no longer being manufactured. Vertical launch modules allow for a wider variety of payloads that can be larger than the 21-inch diameter of standard heavyweight torpedo tubes. It also allows the Weapon Stowage Compartment to carry a full load of torpedoes and mines with the land-attack missiles relocated in the VL modules. Hypersonic or cruise missile launch capability to strike both land and shipping targets will be a key requirement for both the RN and RAN. The ability to penetrate anti-access and area denial (A2/AD) bubbles with little or no warning will provide a critical conventional deterrent to the primary adversaries.
The US Navy has already made the move to vertical launch systems for conventional missiles with the conversion of four former SSBNs into SSGNs. When these boats retire, some of this firepower will be retained by the addition of the Virginia Payload Tubes (VPT) to the Block IV boats and Virginia Payload Module (VPM) to the Block V Virginia-class SSNs. The adoption of the VPM or equivalent by SSN(R) would give the three navies very useful commonality. For the Australians that already use predominately US-made weapons, this would be especially important as they may also share operating bases such as Guam and Perth where common weapons stocks could be held. If VPM compatible, the RN boats could potentially be armed with a submarine-launched variant of the Future Cruise and Anti-Ship missile (FCASW) currently being jointly developed with the French.
The VPM is a large circular tube containing 7 cells for strike-length missiles. The VPM is accessible from within the pressure hull which allows access for servicing larger weapons (that must be loaded by crane into the cells when alongside). This also offers the possibility of using one module as a diver lockout chamber for special forces missions. The addition of VPM to SSN(R) would probably preclude the fitting of a Dry Deck Shelter which the Astutes are capable of carrying. The number of VPM selected for SSN(R) would probably be a cost-driven decision, potentially between 2 to 4 modules.
The Dreadnoughts have hull-mounted forward hydroplanes, as opposed to the upper casing mounts employed by the Astutes. Assuming SSN(R) follows the same practice, also a feature of the older Trafalgar class, this allows for a sleeker hull form. The hydroplane actuators occupy space in the pressure hull although easing maintenance they also need to be retractable for coming alongside.
SSN(R) is also likely to have the X-form tail of Dreadnought, which is more complex to build and control but is quieter than the conventional cruciform arrangement of the Astutes. This is because the control surfaces can exert the same effect with a smaller surface area, and are not in line with the fin, reducing cavitation and turbulence. With the High North assuming greater strategic importance for the UK, to facilitate operations in the Arctic, SSN(R) may have a strengthened fin that can punch through the ice, although this is obviously not an important requirement for the RAN.
From concept to reality
Although delivery SSN(R) seems a long way off, the implications will be immediate. As we considered in a previous article, the race is now on for Australia to expand its cadre of submariners including nuclear-qualified engineers and watchkeepers, together with a skilled workforce to maintain their new fleet. On the waterfront, there will need to be heavy investment in infrastructure to enable construction as well as support the boats in service.
A completely new regulatory environment will have to be established from scratch and security procedures and vetting of personnel raised to a much higher standard. Recruiting specialist engineers and submarine builders to South Australia from overseas must be done with care and not by poaching from the finite talents of their AUKUS partners. It will likely not be funding, but securing adequate numbers of SQEP (Suitably Qualified and Experienced People) that will be the biggest single factor defining whether the AUKUS Submarine programme can be successfully delivered.
In the UK the design teams developing SSN(R) unaccustomed to working in a joint programme must now account for the requirements of the RAN as well as their regular RN customer. The areas that will probably be the greatest challenge will be to design a boat that can accommodate either the US-derived combat systems, sensors and weaponry utilised by the RAN as well as the next generation of RN systems that follow from Astute and Dreadnought. Since combat system integration is one of the most demanding and expensive tasks, the more commonality that can be agreed upon between the RAN and RN, the better. The implications of nuclear acquisition, ownership and through-life management will present a steep learning curve for the Australians who will be entirely reliant on their partners in the initial stages and must adhere to strict new management and safety regimes.
Understandably the Australians want to undertake as much of the construction as possible domestically and are committed to creating a shipyard capable of nuclear submarine assembly at Osborne shipyard in South Australia. The UK defence industry is already working to assist the Australians, with BAE Systems providing expertise at Osborne for the construction of the Hunter class frigates. Babcock recently announced the appointment of the former Second Sea Lord, Vice Admiral Nick Hine will lead a newly established division for delivery of AUKUS capabilities.
The workforce employed by BAE Systems in Barrow in Furness is already being expanded from 10,000 to 17,000 to support Dreadnought and SSN(R). Besides the expansion of the design teams, in the longer term, this enormous increase in staff may also enable significant parts of the Australian boats to be built in the UK. The highly enriched uranium (HEU) will be provided by the UK or US and it is probable the PWR3 reactors for the RAN boats would be made by Rolls Royce in Derby and then assembled in Barrow. The complete reactor compartment would then be shipped to Australia for insertion into the boats built at the Osborne yard.
The commercial contracts signed by the Australian government are likely to lock them in for the long-term with unaffordable penalties for cancellation. With strategic investments that run into the $billions, UK and US navies and the companies involved will not be willing to risk the Australians backing out, should there be shifts in government direction, public opinion or the geo-political situation. There is already plenty of domestic opposition to the project estimated to cost between A$125 – A$200Bn over 30 years. Leaders in Australia must be willing to commit to sustaining the submarine enterprise over several decades and underwrite it with full funding and political support.
The RAN was modelled on the RN and until the 1960s was predominantly equipped with warships and submarines that were either British-built or designed. As the UK focussed more on Europe, withdrew from the Pacific and dramatically scaled back its navy, the close bond between the RAN and RN faded. The selection of the British-designed Hunter class Type 26 derivative in 2019 and now SSN(R) to follow, is a natural return to the close partnership between two navies with a shared heritage.
AUKUS is really the child of another unwanted global arms race triggered by China conducting one of the most rapid military build-ups in history, now launching warships and submarines roughly equivalent to the entire Royal Navy every four years. SSNs will provide Australia with a big increase in capability and share the burden with the US in defending themselves and their partners in the Pacific. From the RN’s perspective, AUKUS is a huge positive, especially if the costs of SSN(R) design can now be spread and there will be economies of scale in the construction and supply chain. More broadly it puts the RN at the centre of a maritime-centric global alliance, sharing leading-edge technology and deepening intelligence cooperation and operating experience.