Although no formal requirement has yet been issued, industry is beginning to explore options for the Royal Navy’s Type 32 Frigate programme. In this article, we look in detail at the warship concept developed by BAE Systems to showcase potential ideas for this future frigate.
The Type 32 frigate programme was first made public by Boris Johnson in November 2020 as the means by which the RN may increase escort numbers in the 2030s. The project formally began the Concept Phase on 21 September 2022 and will seek to deliver an Outline Business Case required before moving to the Assessment Phase. From what has been stated publicly about the project, it has been possible for BAES to develop the Adaptable Strike Frigate concept (ASF) as a credible outline design to meet the likely needs of the navy. It also serves as a starting point for discussion with potential industry partners and with possible export customers.
The ASF design flows from the themes that have been outlined in the Integrated Review (IR) and Defence Command Paper (DCP) published in March 2021 and the Maritime Operating Concept (MarOpC) published in September 2022. In broad terms, this demands a frigate that is digitally and data-enabled, ‘protean’ (able to rapidly re-role), will utilise off-board autonomous capabilities and provide a persistent presence overseas. Increased automation on the ship and a very low core crew requirement is also part of the vision for what will eventually be one of three frigate classes, operating with Type 26 and Type 31s. Initially, Type 32 was perceived as being primarily a mothership for autonomous mine warfare systems. Although this will be one of its roles, Admiral Radakin subsequently confirmed it would be a general-purpose frigate.
There is no budget or specific cost target attached to Type 32 as yet, although it is expected to be a 5-ship programme and seen as a follow-on from Type 31. It is unlikely to be a high-end combatant and BAES says the platform price for ASF would be in the £250-300M ballpark, with the weapon/sensor fit and modular capabilities to be selected by the customer at additional cost.
A ship of two halves
To some extent, the ASF is the answer to a question that has not yet been asked. Lacking a detailed specification has allowed the designers a degree of freedom and creativity to think differently. BAES has not designed a warship from scratch in some time – the Leander Type 31 candidate was a development of the Khareef-class corvette. CGI renderings and a well-presented model should not be confused with a detailed ship design and there would be a great deal of work to be done to take this concept to a stage where manufacturing could begin.
BAES naval architects have, however, matured the hull design to a point where structural strength and stability calculations have been done to ensure this is a viable and seaworthy platform. The result is a vessel of similar size to the Type 31, with a length of 130m, displacing approximately 6,000 tonnes.
The forward end of the ship is much like a conventional frigate design with space for a gun and VLS cells. The weapons shown on the CGI and model are just placeholders but there is plenty of space available for a gun and missile combinations that could provide the ship with anything from basic self-defence capabilities to area air defence or land strike capabilities. The equipment fit can be defined by the customer and it would be a mistake to focus too much on the weapon and sensors at this conceptual stage. The forward section also houses the operations room, main accommodation spaces, mainmast for the primary radar and ISR systems.
The main ASF innovations are in the aft half of the vessel. The section has four main components, the large mission bay with stern ramp, hangars for a medium helicopter and UAVs, 4 boat bays and the machinery spaces. The mission bay extends the full length and width of the space under the Chinook-capable flight deck. On the centreline is the stern ramp with a launch and recovery system that can accommodate USVs and UUVs. A ramp system is safer to operate in higher sea states and can cope with heavier payloads than the crane-type mission bay handling system of the Type 26.
The mission bay is accessible from the dockside through side doors and the main area allows containers or vehicles to be manoeuvred either onto the ramp or into side bays for storage or to launch lighter items over the stern using A-frames. A tunnel running under the hangar provides access to an elevator where containers can be raised to the deck space amidships. The RN’s PODS concept envisages that some payloads such as small UAVs or even missiles could be launched directly from containers placed on the upper deck.
BAES has worked with a variety of suppliers at engineer to engineer level in order to offer different capability options. The stern ramp is made by Palfinger which uses quad-wheel drive units to raise and lower payloads up and down the incline. ASF has the capacity to embark up to 20 x Twenty Foot Equivalent containers (TEU) to provide modularised capabilities and additional stores. Movement of containers on board would be facilitated by the Cube™ system developed by SH Defence and allows the ship to rapidly re-role by embarking different modules and autonomous vehicles. A core ships’ company of around 60 would be joined by teams of specialist augmentees embarked for different missions.
The 4 boat bays provide space for a variety of surface craft launched using conventional davits. In the littoral strike role, boats stored in the mission bay and launched down the ramp could be supplemented by two further craft. Steller Systems were engaged by BAES to provide an example vessel, they have a portfolio of uncrewed surface and subsurface craft including the Wraith Uncrewed Surface & Subsurface Vessel (USSV) featured on the model. To support the Future Commando Force, the MoD issued a tender in September 2022 for a USSV capable of deploying sensors and effectors while surfaced or submerged.
The ASF is not equipped with hull-mounted sonars or towed array sonars but if required to perform in the ASW role, can support helicopters/UAV operations by embarking UUVs or a containerised TAS. Following on from experiments with the MSubs Manta XLUUV, in January 2022 the MoD issued a £21.5M tender for another autonomous submersible, part of Project Cetus. BAES is now developing Herne, its own XLUUV solution. Both the USSV and Cetus XLUUV are required to fit within a larger Forty Foot Equivalent container (FEU).
The MarOpC envisages a future fleet that will be increasingly enabled by digital data networks. This will be necessary to support desegregated naval operations dispersed over a wide area but also for the local command and control of autonomous assets. ASF has been designed from the outset with a ‘digital backbone’, providing interfaces for modular assets to plug into as they are embarked for different mission sets. BAES has been exploring secure cloud-based data sharing with Microsoft to support ASF and naval operations.
Details of the propulsion system for the ASF have not been precisely defined or the particular prime movers specified. For now at least, the concept envisages a combined diesel-electric and diesel-mechanical (CODED) system. A centreline shaft with direct diesel drive is complemented by two azipods. The propellers are turned by electric motors inside the pods which can be rotated around their own axis to provide steering for the ship. The two pods, one shaft arrangement provides a measure of redundancy and has good hydrodynamic efficiency, compared with twin screws on long shafts supported by brackets.
Until recently podded propulsion for warships has been considered too risky due to poor shock resistance. In the commercial shipping world, azipods continue to be widely adopted and the technology has matured to a point where they have become very reliable and robust. Combined with an optional bow thruster, azipods provide exceptional low-speed manoeuvrability, useful in harbour but could also help maintain precise positioning when recovering craft at sea. The RN has some experience with podded propulsion as they are fitted to the Echo-class survey ships, RFA Bay class and are being proposed by Team UK for their Fleet Solid Support ship design. For the ASF concept, BAES has worked with ABB who have 30 years of experience in developing and manufacturing azipods.
The IR stated that defence must seek to reduce emissions as part of the government plan to make the UK a net-zero contributor to greenhouse gases by 2050. BAES has been working with Rolls Royce to explore how ultra-efficient diesel-electric propulsion can help reduce emissions with the added benefits of economy and increased range. Novel power generation solutions are also being considered. It is now possible to fit a 10MW gas turbine generator inside a container which could be embarked to provide additional electrical power when needed.
Collaborate or compete?
Although their Glasgow yards will be building the Type 26 frigates into the 2040s, BAES will have some spare shipbuilding capacity available, especially following their investment in a covered build hall at Govan. They also have available capacity within their naval architecture, design and engineering teams. Should the ASF be entered as a candidate for a possible Type 32 competition, BAES could also be open to adopting a distributed build strategy involving other yards. BAES believe the ASF has export potential and would consider a joint construction programme with an overseas navy.
From a purely industrial perspective, it would make sense for Babcock to build Type 32, following on directly from Type 31 construction in Rosyth. This would likely be the quickest and most affordable solution but this is speculation only and much depends on the navy providing a detailed requirement. Babcock says it would be possible to stretch the Arrowhead-140/Type 31 hull slightly if more capacity was required. The midships section could be completely reworked with a much larger mission bay.
It is too early to say what procurement strategy will be adopted for Type 32. The MoD’s default method is to run a competition for major projects but greater industrial collaboration could be a sensible way to deliver value for money from UK suppliers. The Aircraft Carrier Alliance proved this model can work and the Team UK consortium is another example of industry choosing to work together. There is no reason, for example, that Babcock could not provide the platform for Type 32 based on the Type 31 hull but with BAES providing the systems and integration expertise, utilising some of the ideas demonstrated in the ASF. Alternatively, if competition is mandated for Type 32, BAES may offer a refined version of ASF pitted against Babcock offering a significantly modified Type 31.