As a lead-in to this post I tried to share my understanding of the broader notion of a frigate, in order to set some context for what I really wanted to wax lyrical about – the new frigate designs that the Royal Navy is developing. I regard the Type 31 frigate project as one of the most interesting and exciting defence procurement challenges we have seen for a long time, mainly because it has the potential to buck the trends set in the Type 45 and Type 26 programmes. It is potentially revolutionary in delivering small, agile warships that meet the Royal Navy’s minimum baseline for a globally deployable combatant. However, this is about capabilities, not just costs – it is essential to ensure that our warships have a minimum capability, or else it is all a waste of money (or worse, a target).

The Royal Navy has been trying to replace its general purpose workhorses for decades. Rather than expand at length, I refer you to the excellent summary written by Think Defence (link here) that takes you on a journey through the Future Surface Combatant, Maritime Coherence Programme, S2C2, Black Swan and the C1, C2 and C3 concepts. Basically we have, since the late nineties, been trying to devise a replacement for the worlds best anti-submarine frigate that has also (by coincidence) turned out to be one of the most versatile and cost-effective surface combatants ever built – the Type 23 ‘Duke’ class towed array guided missile frigate, helicopter carrying (FFGH).

The role of British frigates

The UK has, since the Second World War, envisioned the frigate as the general purpose workhorse of the fleet and its primary anti-submarine warfare platform. Up until the current squeeze on hull numbers, and with the limited carrier capability we had in the CVS (and its subsequent deletion), the task was routine patrol – good frigate tasking – in the Gulf, South Atlantic, North Atlantic, Mediterranean and the occasional global deployment. That is about to change.

With two massive aircraft carriers coming into service, the RN will shift from singleton deployments to carrier task force operations. The ambition is known, two Type 45 destroyers and two Type 23 towed-array frigates as the escort, nothing less. It doesn’t take a genius to work out that such a task force is going to rewrite the RN’s operating ethos completely. For a start, getting two Type 45 destroyers to sea at the same time is going to be a challenge, but we still have time before the first operational deployment of the QNLZ.

Two ASW platforms also means that the Type 23 FFTA’s, and eventually the Type 26s, will end up being near permanently tasked with carrier escort. More importantly, however, the FFTA’s are a crucial element of the nuclear deterrent defence, a task which trumps all others. On that basis, even with the carrier in port, the Type 26 force is unlikely to end up being able to conduct the traditional singleton deployments that give us our wider influence. That task will fall to Type 31 and on that basis, five hulls to maintain global presence just doesn’t seem like enough. Mind you, if it is a showcase of British design skill and military effectiveness, it can perhaps sell itself.

The Cold War evolved our ASW capabilities to ultimately devise the Type 22 frigate. What became clear, however, was that the Type 22s were too costly to become the sole frigates of the fleet and the Leanders were not delivering the additional ASW capability that was needed. Thus was born the Type 23, a cheap towed-array tug to replace the Leanders, with an advanced helicopter that could chase down Soviet submarines in the GIUK gap. Thanks in part to the Falklands War and lessons from the Type 22s, they were substantially enhanced with improved damage control equipment, a main gun and defensive and offensive missile armament, thus becoming a truly general-purpose combatant that the UK continued to operate in the frigate role. Type 23 was quiet, efficient, well-armed and flexible – a model we should, really, have espoused for its replacement. To repeat my assessment regarding frigates, such a vessel has to be able to survive and offer some sort of high-end military capability, otherwise it is just a patrol vessel in someone else’s back yard and carries no diplomatic weight.

If Type 31 is going to pick up the globally deployed singleton role, then it’s capabilities, more than ever, cannot be skimped on.

The Type 26

As you will (hopefully) have read, Type 31 was born out of the 2015 SDSR after it became apparent that Type 26 was going to be too expensive. This fact is one that has me baffled, because throughout the concept and assessment phases of Type 26 development, one of the key underlying factors was cost efficiency. The hull might be new, but the weapons, sensors and combat systems were all going to be pulled through from the Type 23. Machinery was going to be COTS/MOTS where possible, and there was nothing, repeat nothing revolutionary about the design.

Let us compare the two for a moment. Leaving aside the fact that the Type 23 definitely had some shortfalls in its design, partly due to the low price of the hull, the two sport virtually identical capabilities:

Acoustically quiet platform.

Long range, efficient hybrid (CODLAG/CODLOG) propulsion system.

VLF active/passive Critical-angle Towed Array Sonar System (CATASS)(Sonar 2087).

Hull-mounted short-ranged sonar (Sonar 2050).

Medium range surveillance radar (Type 997).

Point defence missile system (Sea Ceptor).

Medium calibre gun (T26 will have the slightly more capable 5″ gun).

Anti-ship missiles (Harpoon, and its eventual replacement).

Capacity for a boarding team and boats.

Capacity for a large helicopter (Merlin).

As it stands, Type 26 will not have an organic ASW weapons system beyond the helicopter – this sounds like a problem, but really short-ranged ASW torpedoes are not much use in the North Atlantic given the standoff ranges you (should) be operating at. However, it does mean the type is dependent on an MPA or quick-reacting helo to engage – which in North Atlantic weather is far from a given.

Type 26 will, however, sport a reasonably impressive Mk41 battery. I say reasonably impressive, but we have no weapons system in inventory to fill it. That is the biggest unanswered question surrounding this platform, and it’s a big problem for me. A new weapon to fill those silos is not going to be cheap, nor is it going to be British or European. If ASROC became an option I’d be very happy, but I suspect that’s unlikely – since these things are going to spend their lives welded to the side of a carrier, the weapon of choice is probably going to be TLAM.

The T26 will also have its vaunted ‘mission bay’. Personally I think this is a gimmick – aside from some extra boats, there is nothing that the ship can sensibly load in container form that will make a blind bit of difference to current operations. It is NOT going to do MCM, it is NOT going to load shipping containers of relief supplies and it is not going to have any form of weapons system in there. Loading up a container that you need in a hurry will mean you either have to launch a boat (to get it out of the way), or you restrict yourself to boat ops on one side only. I cannot see anything revolutionary coming out of a ‘mission bay’ – call it what it is, a boat bay, stick some unmanned surface vessels in there, and you have a capability worth discussing. But like the Mk41, the ‘mission bay’ is basically underused.

So, to sum up, Type 26 – it’s a big Type 23, and it costs about four to six times as much (depending on what cost estimate you use). So far, conservative estimates are going at about £750M-£1BN per hull. Add to that the recent news that the build is going to be stretched over eight years (about the same as QNLZ), and the first of class will not be in service before 2027. The early Type 23s are going to be very tired by the time Type 26 arrives.

One billion pounds.

Another ten years away.

If cost efficiency was ever a key requirement, then Type 26 has failed already.

Why has Type 26 failed?

I’m going to go out on a limb here and be controversial. Unless there is a better explanation out there, this is what I think has happened.

We know the RN is under huge pressures in manning, and the retention of suitably qualified and experienced personnel, especially in the naval design area, is a huge challenge. And although the design is largely undertaken by the contractor, the RN still has a key input for standards and requirements to set the overall capability required from the ship. Since the experience already exists, can it be that the shortfall in SQEP design personnel, coupled with the RN’s continued manpower challenges and frequent rotation of personnel, has led to changing requirements that, in turn, have driven major (and thus costly) design revisions? Or worst case, have we lost the SQEP altogether, both in the Service and in industry, and are the changes and costs being driven by elementary mistakes in design?

I do not doubt for a moment that Type 26 will be exceptionally capable in its primary role of North Atlantic ASW, if it turns out to be quiet enough. The 2087 active/passive towed array system and the Merlin Mk2 helicopter, coupled with the P-8A Poseidon (and the tantalising possibility of ASROC), will make for a formidable SSN hunter and deterrent capability. But it is excruciatingly expensive, does not represent a generational leap beyond Type 23, and set against the backdrop of hard cuts in escort numbers in the last twenty years we have effectively inflicted a further cut on ourselves by failing to control the programme. I also think it is over specialised for the North Atlantic, which (like it or not) is still the highest priority for the RN over and above Carrier Strike.

What might have been – Type 23+

The failure of Type 26 to meet its cost target has, in my view, undone both the SDSR 2010 decision to merge the Future Surface Combatant (FSC) C1 and C2 designs, and the earlier Sustained Surface Combatant Capability (S2C2) design studies that proposed the C1 and C2 should share a common hull (make sure you have read Think Defence’s piece on Type 26 here – it is excellent). Moreover, it has effectively wasted all of that effort poured into those studies since the 1990’s, and the only design we have is a large Type 23. So why didn’t we just build more Type 23s?

I am a huge fan of this idea and I’m tired of engineers telling me it’s not possible or feasible. It is perfectly possible – so long as you understand and accept the inherent limitations of this design. Unfortunately the engineers won out and a new platform was much too attractive, both for industry and, probably, for ambitious RN officers.

The Type 23 has been, in my view, the most successful warship design in our recent history. It was low-cost, yet has evolved brilliantly in its 30+ year history. The last hull was HMS ST ALBANS commissioned in 2002, so our design and build experience with the type is very recent. And we have those decades of experience and a massive stack of lessons identified in the class, almost defect and design flaw identified, mitigated and managed. Engineers will tell you that the class cannot evolve further due to reduced growth margins, power generation limitations, structural shortfalls and evolving standards. Rubbish.

A new-build design would not be saddled with the inevitable weight growth that comes with years of paint and minor modifications – it’s a clean hull, so you start again. Structural defects can be addressed because we know where they are. Spaces can be changed, and have – the opening up of the Sea Wolf tracker offices and Ops Room Annex (thanks to Sea Ceptor and improving computer technology) are just two examples. Lightweight materials can be introduced into the design to reduce topweight – a small but incremental gain that opens up your design margins. If the current design can work for 30 years or more, so can the new one – and that’s good enough.

Because the design already works for the RN, it does not need to have complex or weighty additional capabilities grafted on. The weapons and sensor fit is sufficient – point defence, medium ranged surveillance, medium calibre gun and so on – basically what Type 26 offers barring the Mk41 and the mission bay. The propulsion plant doubtless needs to be upgraded, but that’s still within the bounds of feasibility – we are not trying to make the platform capable of 45kts, but to achieve the current design speed more efficiently and more reliably. New generators and, perhaps, a redesigned boost capability based on a single MT30 vice twin Speys, plus a refreshed electrical distribution system, are well within the scope of feasibility without complexity. You might even consider reverting to a diesel-only CODAD/CODOD arrangement – which would eliminate the upper diesel spaces and generate even more capacity. I can also conceive of a rearrangement of the design, moving part or all of the Sea Ceptor silo aft and opening up the forward silo to a small Mk41 or ExLS that could deploy ASROC or a future ASM. And if you move the 30mm cannons aft to the hangar, you can achieve additional boat carriage capacity amidships. Minor, but useful changes.

So, neither free nor cheap, nor an Arleigh Burke substitute. But, and this is central to my argument, it would be considerably less than the Type 26 design, could have maintained RN corporate design experience, and ultimately would have delivered a significantly less risky platform that would have served very well for another 30-40 years. And with such experience behind it, the design would be attractive for export. If the US can do this with the Arleigh Burke, and Blohm+Voss with the MEKO design, we should have been able to do likewise.

Type 31

Type 23+ was never meant to be – a pity we couldn’t stand back from the problem set and take a measured long view. What we are left with is a now desperate need to arrest the rapid decline in hull numbers with a new design, and from this sense of urgency and an overdrawn bank account is born the Type 31.

In my previous post on frigates I outlined what I considered to be the minimum requirements for an effective combatant – endurance and survivability. To that we now have to add further financial rigour, to make sure we do not cross the line again. I’ve also made it clear, I hope, that the non-tail fitted Type 23 is a very good baseline for what I consider our replacement capability to be, especially in the ‘survivability’ bracket. And I hopefully have highlighted already that Type 31 cannot just be a patrol boat – this thing will be out on its own for a long time.

By opting for an all-new hull, we have effectively gone back over forty years to the early 1970’s and the decision to acquire the Type 21 frigate. So be it. Unlike in the early ‘70s, however, the manner in which the RN now develops its weapons and sensors has made them platform-agnostic, with a common PDMS, close range guns, sensors, ESM suites, combat system, etc, so all we have to do is design the platform. This, then, is my take on Type 31.

Designing a platform with endurance is simple. Large fuel tanks, efficient engines, seaboats, RAS gear, cold rooms and fridges and adequate accommodation are obvious examples. Maintenance is a major limiting factor, but technology has evolved and gas turbines and diesels are as low-maintenance now as ever before. The complexity of some systems does demand more in the way of contractual support overseas, but so long as any design avoids exotic engineering solutions (Type 45) this requirement is technically simple. We know how to divide ships to enhance their survivability, thus enabling them to operate with damage (whether natural or from enemy action). The RN has the long deployment coded deep in its DNA; it is in the way we train and fight that allows us to operate so far from home for so long, and so long as we continue that ethos we can retain our global range and endurance. The remaining factor is crew – and the RN standard of being able to sustain the Defence Watch (24/7 heightened readiness) has to be the baseline.

In terms of survivability, the platform must be able to defend itself (and others to a limited extent), and in this I will consider above-water and under-water warfare in turn. Above water the threat is the proliferation of anti-ship missile types. Large and small, subsonic and hypersonic, old and new, these threats are considerable and long-ranged. A frigate cannot deal with them at long-range and equally cannot defend a large number of units – this is why we have AAW destroyers (and Type 45 is one of, if not the best in class). But on isolated patrol and for small escort tasks, the Type 31 needs to be able to counter a moderately determined attack. This demands a radar, ESM surveillance and a weapon system – and the RN already has Radar Type 997, UAT (and evolving variants) and the SeaCeptor missile, all state-of-the-art, capable and with their own development spirals, plus the systems already exist or are planned to exist on the non-tail Type 23’s.

Underwater, the best defence is definitely a strong offence. The decision to split the frigate force into two types eliminates, in my opinion, the acoustic stealth requirement (which may, or may not have been one of the cost drivers in Type 26). Type 31 will not be required to trawl a towed array and sit quietly in the Atlantic – that is now the preserve of the Type 26. The primary underwater threat the Type 31 will deal with is not the speedy SSN in deep water but the slow, silent SSK in the cluttered and deafening littoral environment, where passive ASW is nearly useless. Active sonars, either hull mounted or variable depth, ASW helicopters, radar and ESM, visual detection and speed/manoeuvre are more critical against the SSK. There are growth options here as well, already covered in my article on USVs. In this environment frigates will most likely be transmitting on active sonar, both to detect and to deter. Countering the SSK is like driving through a lawless city – most of the time speed and manoeuvre will keep you safe, but when the attack comes it’s a knife-fight in a phone box.

What a frigate (or any warship, really) needs is the ability to react quickly to a submarine detection. Again, speed and manoeuvre figure prominently here as does the ability to get weapons onto a datum. Against a concerted SSK attack we are likely to take hits, but submariners are not suicidal and if they are located, they can be driven off or sunk in short order – there is nowhere to hide once a Merlin starts dumping active sonobuoys around you. Active multistatic sonars extend this advantage further. If funding exists for the installation of the Mk41 VLS system and the acquisition of a weapon system for it, then the ASROC is a more effective alternative to shipborne torpedo tubes.

Secondary considerations

I believe these to be the baseline, but other factors exist which bear merit. The RN still maintains an amphibious capability, and experience suggests that a large calibre main gun is worth having for the NGS role, especially if guided ammunition is available (in an age of political demand for precision). But the Type 26 and Type 45 both have large guns already, so could the Type 31 dispense with a large gun (as the Type 22 did)? Or could the 76mm gun make a reappearance to counter the FAC/FIAC threat, noting that the Wildcat carries both Sea Venom and Martlet? A Type 31 with Sea Ceptor and Phalanx 1B (or a future laser weapon) could potentially sit much closer inshore than a Type 45, providing an air-defence umbrella to the raiding forces, although not at insignificant risk and requiring early warning from the Type 45 and any AEW asset that might be operating.

In our current operational environment, the need for an anti-shipping cruise missile is currently depressed by some margin. I think it is necessary to have such a system, but I place the ASW capabilities ahead of this requirement – I don’t see our frigates hunting enemy surface combatants alone. However, it should be a consideration nonetheless. The RN continues to rely upon the venerable Harpoon for its anti-surface weapon, but wheels are in motion in the US to replace it and a new system may yet be selected. If nothing else, whatever the RN selects as its future anti shipping weapon, we should make sure the Type 31 is at the least fitted ‘for, but not with’.

UAVs are becoming cheaper and simpler to operate. However, as yet I see no justification for major warship design compromise to accommodate any such system. The launch and recovery equipment for ScanEagle represents the likely top-end of assisted launching, and this fitted comfortably on a Type 23 without compromising helicopter operations. VTOL UAVs require only the hangar and deck. Whilst more might be argued if we embarked a Predator-sized UAV, the cost and risk is not justified at this stage. Personally I have a lot of time for the ScanEagle and Blackjack and their ability to extend the surveillance horizon at minimal cost and risk, especially their launch and recovery systems and the endurance of the ScanEagle.

Above all else, this is a warship. Headline-grabbing disaster relief missions do not justify compromise in the warfighting design nor expensive additional capabilities – whatever they might be. At best, space to secure a couple of ISO containers containing relief supplies might be considered, but we have storage space belowdecks already. Counter-piracy is a potential task, but again the existing combat capabilities of the vessel should be more than adequate, demanding only additional accommodation for Royal Marine boarding teams. We should continue to invest in our RFAs and capital ships to hold the meaningful disaster relief capability – by all means have a read of my views here. The one capability I would consider is a bow thruster. Warships tend not to have these (the OHP frigate was a notable exception), but the advantage of such a thruster is that the ship becomes less reliant on host nation support for berthing and unberthing – in a devastated port or deprived area, the ability to dispense with tugs could be invaluable.

What Type 31 cannot be

Anything less capable than the primary considerations outlined above is, in my view, a waste of money. At the first sign of an airborne threat, it becomes a liability. Equally a warship without at least some ASW capability is at risk the second an SSK puts to sea (the reverse of the CONQUEROR/BELGRANO case study). There is a clear minimum baseline capability to meet the criteria for an effective, globally-deployable independent warship. Type 31 cannot be an up-gunned OPV.

Type 31 is also unlikely to be a suitable platform for an AAW variant. The smaller size of the hull will limit the size and weight of any capable air surveillance radar that could be fitted, reducing the radar horizon and limiting the ability to detect low-flying threats at sufficient range. Weapon capacity is also an issue – Type 45 has 48 cells and is commonly regarded as having too few missiles, especially when compared to the Arleigh Burke’s 96-cell capacity. The Type 26, however, might be a better bet if that requirement ever became an option.

Future Proofing

It is difficult to future-proof any military system because of the long timescales involved in designing and building complex warships. But this is nothing new. By the time the County class destroyer was in service with the Sea Slug missile system, the latter was borderline obsolete already. Other examples exist, so the lesson should be to provide space for change, and influence developmental programmes to remain aligned to naval limitations. Exotic solutions tend towards failure – and here I would cite Type 45 propulsion, the Littoral Combat Ship and the cost of the Zumwalt destroyer as examples.

I believe that few, if any future game-changing capabilities are likely to require large, costly installations or extensive reconstruction at the frigate level. Even railguns, under development now, are unlikely to make a single warship suddenly an order of magnitude more effective – and they are under development, not ready. The best example I can think of is electronic warfare, including cyber capabilities. Such capabilities are only going to increase in importance, yet they require only server space, cooling and transmission systems – all of which exist already in a complex warship. A sufficient growth margin should be factored into power, cooling and aerial capacity.

And as our doctrine develops in response to Russian and Chinese progress in the past decade, technological innovation is now seen as the route to future battlefield success (the US Third Offset Strategy, or at least my understanding of it). I would argue that it is more critical to have a hull in the right place at the right time, otherwise no exotic capability is ever going to deliver an advantage. We cannot deliver effect with our stealth-swarming-self-3D-printing-drone-battleships if we only have one. We need the numbers to ensure that we can achieve a forward presence, and that in itself demands a low cost per unit.

The role of Industry

The cost failings in the Type 26 design should tell us that we cannot approach Type 31 in the same way. If we set out to design a Type 23 replacement and ended up with Type 26, then Type 31 will also have failed in the same way.

What we should trial is passing the design process over to industry, and accepting that there will be compromises in the design that are not the RN way of doing things, but which can prompt adaptation and innovation as well. The National Shipbuilding Strategy outlined the potential for modular construction and assembly, and several promising designs are already on the table.

The best approach would be to select a design and follow the prototyping or batch-building route. By ordering one, two or three initial hulls, we will at least acquire the basic platform and can understand its shortfalls as well as its capabilities. The proposed industry model supports this, as it will not leave yards waiting for work if they are able to return to other complex shipbuilding tasks in the interim.

Equally importantly, the RN as a whole should provide broad consultation on the proposed design to identify any significant shortcomings. This must be done in a controlled manner, by providing one or two contractually agreed input moments as well as a coherent and fixed set of design requirements at the beginning. Vesting this critical input in a handful of personnel (most of whom will not stay in that job long enough to see the final design, let alone the first of class) must not happen unless a long-term, sustainable Naval Design career stream is developed. Once the kinks have been worked out from the first examples, a modified design can be produced for the next batch. This also opens the way for export orders, as the design can be tagged as ‘developed by the Royal Navy’, a powerful export incentive. The early hulls can either be tasked operationally or, if they are deficient in some way, kept back for lower intensity operations or sold to other nations who do not share our high specifications. The concept of Tranche 1, 2, 3, etc works in many other industries, and there is no reason why the Type 31 could not be the basis for RN frigates for decades to come.

By transferring the design risk to industry, following the build-assess-build model, selecting a baseline global warship design that embraces RN experience and equipment, and maintaining key stakeholder engagement at all levels, an affordable, capable, appropriate future frigate is achievable.

Summary

Hopefully I have made a decent case for the minimum requirements of a frigate that meets the RN’s requirement, and proposed a potential route to acquiring this at the right price by transferring design risk to industry but accepting certain compromises in design for the sake of platform development. There is huge potential here – we should seize this, sustain it, and learn the lessons from our past failings.