New technological threats and new operational requirements are emerging in the naval environment, raising the question of how ship and submarine designs should develop in response. For naval architects, this presents new challenges, but also new opportunities.
In December 2022, the UK Royal Navy’s (RN’s) first-in-class anti-submarine warfare (ASW)-focused Type 26 frigate, the future HMS Glasgow, entered the water for the first time. The RN has often stated that Type 26, as an ASW platform, was designed from the keel up using submarine technology to deliver acoustic quieting.
On 1 October 2023, the UK government issued a contract award for the detail design of the new nuclear-powered attack submarine (SSN) that will provide the next-generation submarine capability for the RN and the Royal Australian Navy, under the Australia/UK/US (AUKUS) strategic partnership. SSN-AUKUS, as the SSN project is currently known, will be based around a UK-derived submarine design.
These two examples, amongst others, highlight the core importance of the baseline design in generating naval capability.
In the contemporary naval environment, emerging threats are driving new operational requirements. New technology is emerging too, and is both driving the threat and enabling the operational response.
In parallel, as threats intensify and as Western navies respond, new naval platforms are arriving. These platforms include not only new classes of traditional naval vessels, like aircraft carriers, destroyers, frigates, patrol vessels, auxiliaries, or submarines, but also new types of vessels, like unmanned systems.
As these new threats, requirements, and vessels emerge, technology is also presenting an opportunity to assess how such manned and unmanned platforms are developed, designed, and built.
Within discussions relating to the development of naval threats, requirements, and capability, there is the question of how the technological shift in the naval world is re-shaping the core, baseline skill of ship and submarine design – in other words, naval architecture.
According to the much-referenced naval architecture book ‘Basic Ship Theory’, “Naval architecture is concerned with ship safety, ship performance, and ship geometry, although these are not exclusive divisions.”
“The use of the term ‘architecture’ is no coincidence; like an architect, the naval architect is the person who draws together the engineering strands in the marine world – part engineer, part integrator, part manager, and part artist, bringing these strands together to consider a ship as a whole system,” Andy Kimber, chief naval architect at BMT, a UK-based engineering design house and consultancy that provides naval architecture capability told Asian Military Review (AMR) in an interview at the Defence and Security Equipment International (DSEI) exhibition in London in September.
BMT’s services include concept, design, engineering, operating, and technology expertise for the RN and other navies. As regards surface ships and submarines, the emergence of new technologies and new threats is having some impact on the process and outputs of naval architecture, including prompting new platforms, designs, and capabilities.
Change but no change
However, there are some elements of the naval architecture process that remain the same, regardless of the threat.
“If you start with naval architecture as an engineering discipline, we are ultimately governed by physics and engineering reality,” said Kimber. “Naval architecture – the theory of it – doesn’t change, because it is what it is. Whether it’s below the sea surface or on the sea surface, the physics is there and our understanding of that physics is reasonably constant.”
“At a level that engineers are interested in, our understanding of physics is very mature,” Kimber continued. “So, in that sense, the stability isn’t changing, laws of resistance don’t change, because the laws of physics aren’t changing.”
“What is changing is the tools available to us to model and understand the platform before it’s built,” Kimber explained.
Here, he underscored how new technology, especially information-based technology, is changing how naval architects get the best out of traditional tools such as computer simulation and modelling. “The digitisation of our industry and the tools that are becoming available are allowing us to analyse the same thing in a different way,” said Kimber. The ability to use digital technology and the increased information levels available provide what he termed a ‘new tool set’. This new tool set does not mean that architectural design, modelling, and testing is done faster and more easily; instead, it can be done more extensively and exhaustively, he explained. “We now want to explore more, so instead of doing five options, we want to do 100 …. We’re seeing our ability to model and integrate things in more complexity grow.”
“We now want to explore more, so instead of doing five options, we want to do 100…”
The ability to try things more extensively offers clear benefits in certain areas of the naval architecture process, Jake Rigby, BMT’s head of innovation and research, told AMR during the DSEI interview. “Especially at the concept stage, because the concept stage is not necessarily about … following a straight-line process to get to the end outcome; it’s exploring the requirements, exploring what solutions could be viable,” said Rigby. “Rather than just looking at a small number of hullform iterations, you can now explore a huge variation.”
Architecture oversight
At DSEI, Team Resolute, a UK-based collaboration between Navantia UK, Harland & Wolff, and BMT, unveiled its latest, evolved design for the RN’s Fleet Solid Support (FSS) ship programme, which will deliver three new UK Royal Fleet Auxiliary (RFA) platforms to support RN carrier strike group (CSG) and other operational requirements. Speaking at DSEI, BMT’s FSS chief engineer Simon Jones explained that, while Navantia will lead on the FSS detail design, BMT’s role is to ensure the continuation of the design intent. In other words, BMT will provide a form of naval architectural oversight, to ensure the detail design adheres to the original concept design.
This underlines how the naval architect’s role covers the entire capability development and delivery process, across pre-concept, concept, design, manufacture, and in-service phases.
“At the concept stage, the naval architect is probably having a greater role, because trying to incorporate many different things at that higher level is the core of what a naval architecture job is,” said Rigby. “[However], as you get to detail design, and into construction, you need the consistency [in] integration and bringing it together.”
“In the early stages … you’re looking at the whole ship, you’re looking at the size, you’re looking at big things. At the end of the process, your hullform is fixed etc, but you’re still looking at the stability because the weight’s still changing, you’ve still got to look at the detail of the structure,” Kimber explained. “The role changes … [but] it’s always there.”
“Naval architecture is the glue holding all the different pieces together,” Rigby added.
Modelling the threat
The improvements in modelling enabled by digitisation mean that naval architects can better understand the risk posed by threat technologies, and whether changes in the threat mandate changes in the design.
“Our ability to model those threats and what they do to the ships is much greater now. The systems we have to simulate how a ship reacts to damage from a threat are much more sophisticated,” said Kimber. “That said, I think the historical lesson is ‘don’t design to the thing today’, because tomorrow will be different.
“The threat is always evolving,” he continued. “We always come back to the basics of what the threat is: the threat is explosive, it’s blast, it’s fragmentation, it’s fire, it’s a hole in the ship.
“The threat angle probably has a greater impact on mission system [designs], in terms of protecting, sensing, and defending from that threat, than it necessarily does to me as a naval architect,” Kimber explained. “I view the threat as ‘if it hits my ship, it’s going to put a hole, it’s going to create a fire, it’s going to do one of a number of things that are well understood.”
Where ship design does relate to the threat is reducing detection risk in the first place, Kimber continued. “That’s where technology does change things, in terms of matching your signatures to the current perceptions of the threat and how you defend the ship.”
“So, I don’t think [the threat] changes what we’re doing as naval architects, but the environment we’re in and some of the solutions change, and we’re putting together a slightly different balance,” said Kimber. Here, Rigby explained, the balance relates to three aspects of survivability: susceptibility to detection; vulnerability relating to capacity to survive any damage and operate; and recoverability, in terms of repairing damage to the ship. “It’s the balance between those three features that changes over time,” Rigby continued. For example, naval architects may have focused historically on the vulnerability issue by designing ships with heavy armour; in more modern times, the emphasis has shifted to lighter-weight, stealthy vessels in tandem with emphasis on recoverability. “This balance continues to change,” Rigby added.
Designing in flexibility
Contemporary capability requirements for naval ships and submarines are increasingly focused on flexibility, designing in the capacity to adjust the capabilities onboard as and when requirements change. The Team Resolute FSS design, which is intended to give the RN flexibility to cover the evolving needs of its CSG and other operational capabilities out to beyond 2050, is designed to be adaptable.
From a naval architectural perspective, this raises the question of how best to design in such flexibility and adaptability to ensure capabilities can be adjusted as and when requirements change.
Ships like FSS, or indeed the RN’s two Queen Elizabeth-class aircraft carriers, have significant capacity onboard, through using large spaces, to enable flexibility in capability. From a design perspective, the challenge is not providing such spaces themselves, however. Instead, Kimber highlighted two issues. First, is how to best design the ship’s structure around that space. “You’ve got to get things on and off the ship, which invariably means going through the structure.” Consequently, the design and positioning of equipment handling systems, rather than the spaces themselves, can create design complexity. Second, is the question of how regularly and quickly the navy concerned may wish to move equipment in and out of such spaces. “The real challenge with flexibility is getting the understanding from a customer around what they really mean,” said Kimber. “Do they mean ‘I want to go alongside and exchange a container, and I want to do it in two hours’, do they mean ‘I want to change my ship over the course of a week’, or do they mean ‘at some point in the future I might want to fit a future system’?” “The solutions to those problems are all a little bit different,” he added.
“There’s a difference between modularity and adaptability,” Rigby continued. “Modularity is where you can immediately switch out [equipment] within a day ….Adaptability is where you can change it alongside with some work.”
“People talk about flexible ships being simpler, but from a naval architect’s point of view, they’re a little bit harder because there’s more moving parts to think about, and some of those moving parts are usually not very well defined,” Kimber added.
Designing out the human?
One new capability area that is subject to much naval architecture focus is the concept, design, and development of maritime unmanned systems (MUS). MUS as an emergent capability present both opportunities and challenges from a design perspective, including the absence of human operators onboard.
BMT has developed its Large Unmanned Surface Vessel (LUSV) concept design, which it launched at DSEI. “That’s quite an interesting challenge for us, because we were going through it thinking ‘if you don’t have humans onboard, what spaces do you need and what spaces don’t you need?’ said Rigby. This can have fundamental effects from a naval architectural perspective, he explained. Having no humans onboard means no requirement to give them space and capacity to work and live.
As regards opportunities, Rigby explained, future fuel types could be incorporated if the space and weight requirements are different. The platform also can be designed with bulkheads closer together, which improves survivability. Different options can be considered for the number and arrangement of decks.
“People account for a lot of volume in a ship. A lot of the empty space is for people – not just to sleep, eat, and recreate, but in the machinery rooms for example it’s for people to move around and access things. We can remove that,” said Kimber. “That’s a lot of volume, although interestingly it’s not a lot of weight.”
“So, you end up with a different balance, and that’s what we’re exploring with LUSV,” Kimber continued. “It changes the traditional balance between how you put a ship together, because a lot of the volume you don’t necessarily need, so what do you use it for?”
Answering this question can present design challenges, Kimber explained, “The conceptualised LUSV has dimensions driven by seaworthiness considerations, and the removal of volume associated with people – mostly empty space – presents an opportunity to increase the volume available for, say, propulsion systems.” However, he added, “These are much heavier so the displacement becomes a limiting constraint to how much volume can be re-purposed.”
Architectural intelligence
A second new technological development that is impacting naval architecture processes is artificial intelligence (AI) – especially, currently, machine learning.
As regards current impact, the important point is not whether AI could supplant human naval architects by, for example, generating ship designs more readily; it cannot yet do that. Instead, the impact is found once more in helping the naval architect tackle time-consuming processes.
“AI is such a broad term. I think what we’re talking about here is machine learning as a specific sub-set,” said Kimber. “We can take the processes that are repetitive, where we can gain advantage by looking at lots of evolutions and iterations, and we can teach the machine what’s good and what’s bad.” “It’s very much at that machine learning end of AI, to basically spend less time processing many options in a specific area of the design,” he added.
Here, AI – and particularly machine learning – “is intelligent in the sense of repeatability and being able to use rule sets …. You still need the human intelligence to guide the artificial intelligence to look at the right thing,” said Kimber. “I can use AI to look at the 1,000 options that I can’t look at – but I still need to give it the parameters around the 1,000 options to look at.”
BMT is already looking in detail at AI’s impact on naval architecture, Rigby explained. “We have a research project continuing next year, looking at AI in ship design,” he said. It will focus particularly on understanding what AI means. “The way we’re breaking that down is we’re not expecting to have a large language model or similar in the near future, where we can just type in ‘build us a new fleet support tanker’, and it will create the full design. That’s not going to happen.”
“What we can do is break down the design process and look at individual tasks,” he continued. “There are some tasks that take considerably more time, with maybe repetitive processes, that we could automate or bring in some aspects of AI – depending on the type, whether that’s reinforcement learning or otherwise – and solve that problem, giving the naval architect or the designer more time to focus on making better design decisions.”
Here, Rigby highlighted the example of hullform assessment. “We’re actively developing hullform automated assessments,” he said. “Usually, we do parametric analysis to look at the different hullforms, assess them, and understand that solution space. With machine learning, what we do is set the solution parameters and use machine learning to explore that entire solution space.” This process generates options for the naval architect to assess. “We can then say ‘That’s a really interesting area: we can explore that more later on’,” he explained.
“The key is, this is not a different approach. That’s how we’ve always designed hullforms,” Kimber added. “The difference is the scalability. With the machine learning, we can set the machine up to assess 1,000s upon 1,000s of options, which we’d never be able to do manually …. It’s just the ability to process more information.”
“I’m still interested to understand whether the machine would beat a very experienced and qualified naval architect.” Kimber continued. “I think there’s … still the role for the really experienced naval architect: what AI is doing is replacing people in doing all the turn-handle calculations.”
“The challenge is that, in naval architecture, there’s never an optimised solution. You can never say ‘oh I’ve got a fully optimised hullform’, because it’s a balance, it’s a compromise,” Rigby added. “The human in the loop is providing that assessment of what the better compromise is, and that’s not something – even with machine learning and other tools – that you can [otherwise] really make.”
by Dr. Lee Willett
