The Lighter Frigate Debate: A Look "Under the Hood"

"Was I to die this moment, 'Want of Frigates' would be found stamped on my heart. No words of mine can express what I have, and am suffering for want of them."

-Horatio Nelson, August 1798

As those who have read my musings on the "lighter frigate" in the past may already know my views on the British government's plan, laid down in the 2015 strategic defence and security review, have been mixed. To some extent I continue to blow hot and cold on the issue. It is now apparent, to me at least, that there is risk inherent in all courses of action when it comes to replacing the Royal Navy's thirteen aging Type 23 frigates. The earlier plan, to build thirteen Type 26 frigates, appears to have fallen afoul of cost and potentially timescale issues. We can criticise the decision to cap the Type 26 build run at the eight anti-submarine configured hulls all we like, but the reality appears to be that BAE's construction yards on the Clyde could not deliver Type 26 at the required tempo without very significant investment (the "frigate factory"). One shipbuild per year was needed to replace the Type 23s as they leave service, without a significant decline in RN escort numbers, whereas the yard currently appears to be scaled for one Type 26 scale shipbuild per 1.5 years.

Presuming that BAE could have delivered at the specified rate of one Type 26 build every 1.5 years it would have resulted in a dramatic decline in the RN's number of escorts, with no realistic chance of recovery until the early 2040s. It would also have likely resulted in a concurrent construction programme, using the same yards, with the Type 45's replacement in the mid-late 2030s. This would have required the Clyde yards to at least double their output of complex warships, a hard ask indeed.

The 13 Type 26 option clearly had some significant problems of its own. It was by no means an "easy" option, requiring a 33% higher build rate than BAE were required to provide under their Terms of Business Agreement with the government, significant investment in new facilities to achieve that higher build rate. Coupled with a higher rate of orders than the MoD was likely capable of funding, without compromising other programmes and we've probably explained the majority of the "witches' brew" that produced the 2015 decision to cap Type 26 at eight hulls and build five or more "lighter frigates".

It's fair to say that this decision has caused more than its fair share of controversy amongst defence commentators. During these early stages hard facts have been very thin on the ground. Most of what we have to go on is based on a few "powerpoint" design concepts put out by BAE, BMT Defence Services and Stellar Systems and Sir John Parker's recommendations for reforming the UK military shipbuilding sector. Bluntly, it isn't a lot and until the government releases its "National Shipbuilding Strategy" at some point soon(ish) we will continue to speculate about the "Lighter Frigate/General Purpose Frigate/Type 31/Type 31e", mostly in the dark. 

It's been suggested that the Lighter Frigate essentially amounts to the "anyone but BAE" option and is a means of undermining their near-monopolistic position in UK military shipbuilding. For some commentators this prospect is deeply worrying, having the potential to fatally undermine the two remaining complex military shipbuilding sites in the country by starving them of orders. For others BAE's monopoly is painted as "the problem" and one of the key reasons why UK-built warships are more expensive than their overseas equivalents. I'm, personally, more inclined to agree with the former position. However, I also see the need for the Lighter Frigate and recognise that it isn't an entirely bad idea from several standpoints.

Firstly, even with a 25% slower build tempo, one Lighter Frigate every two years, escort numbers remain relatively stable; dipping to lows of only 18. 

Secondly, 8 Type 26 at 1.5 year intervals dovetail neatly with the projected start of the Type 45 replacement programme without the need for concurrency. This indicates to me that the "Lighter Frigate undermines BAE" argument may be too harsh. There is a steady stream of the sort of high-end complex warship building work that BAE provides on the Clyde available for those yards well into the future. 

Thirdly, one of the most astute criticisms is that bringing the Lighter Frigate from the concept stage, where we are at present, to a full-fledged design able to be built is going to take time and cost money. This is absolutely the case and where much of the risk lies. However, it is not impossible to design and develop a surface escort to a constrained timescale. Doing so may actually help avoid the problems which emerge when a steady stream of additions and amendemnts are made to a design specification the longer it takes to bring it to fruition. A process that, as Type 26 demonstrates, can add significantly to development costs. It may also limit the scope for bespoke or "revolutionary" components, with designers forced to turn to off the shelf equipment and machinery. A more constrained timescale for designing the Lighter Frigate may actually prove beneficial if it produces a well-executed, but conservative, design.

An earlier and much more modest iteration of Type 26

Fourth, there is justified concern about the viability of the proposed "block build" approach that is intended to spread work to other, smaller, yards around the UK. There are evidently issues with this approach related to the shortage of yards with the necessary skilled workforce, equipment and facilities to efficiently build blocks for a complex surface combatant. While work on blocks for the carriers appears to be a positive indication of their skills and capacity to deliver, it remains to be seen if a similar model can be made to work for the Lighter Frigate. The other issue with this approach is the apparent lack of a suitable "integration yard" (where the blocks are assembled into a functioning warship).

"The vessel should be assembled in a shipyard, backed by a company or alliance with sufficient financial and industrial capacity and capability to construct and commission and enter into the key sub-contracts."

-Parker Report, 2016

There are a very limited set of options on this front. While Sir John Parker's report suggests that BAE should concentrate their efforts on Type 26 their yards on the Clyde would be an obvious option, provided that the risk of concurrently building Type 26 and integrating blocks for the Lighter Frigate could be mitigated. Unfortunately viable alternatives are very thin on the ground. Babcock international's Appledore yard is too small and their Rosyth yard, where the carriers have been constructed, is soon to become the hub for UK nuclear submarine decommissioning. Cammel Laird on Merseyside have the facilities but likely lack the skilled workforce necessary to integrate a complex warship. Their performance constructing the UK polar research ship RRS David Attenborough may give some indication of just how capable they are in this regard. Harland and Wolff's yard in Belfast is large enough, but the company hasn't built ships (let alone anything as complex as a warship) for years, having diversified heavily into the offshore wind sector. Other "options", such as re-opening the Portsmouth construction yard, are little more than fantasy.

The options for the integration yard are extremely limited, realistically boiling down to BAE on the Clyde and Cammel Laird. The latter being a much more risky option that would almost certainly require a consortium that included BAE, to bring their skills and experience to bear, in order to make it work. It would also likely require an expansion and upskilling of Cammel Laird's modestly-sized workforce. Ultimately it might be better to focus efforts on a single complex builder, BAE on the Clyde. However, this could introduce risks to the Type 26 programme. The optimal means of mitigating those risks might be to use BAE as an assembly yard only for the Lighter Frigate, keeping all fabrication activities seperate by farming them out to the smaller yards.

Cammel Laird's yard in Merseyside

If the UK government is serious about building up a second complex military shipbuilder, it needs to consider the implications on continued investment in the Royal Navy and Fleet Auxiliary that will be necessary to sustain two yards. In shipbuilding consistent investment and orders are critical. It will be no different in this case than it is with BAE.

Overall, the Lighter Frigate is simultaneously necessary and difficult to realise. Contrary to some commentators' views, I'm firm in my belief that 13 Type 26 isn't the "magic wand" answer to this problem. A long-term failure to invest in military shipbuilding has led us to a place where there are no easy options. Blaming all of our woes on BAE's monopoly is unhelpful and disguises systematic failures in the government's military industrial strategy. "Competition" isn't a magic wand either, undermining BAE with no real alternative would be the height of irresponsibility. The only way to make a semi-competitive military shipbuilding system work would be to build a significantly larger Royal Navy, able to naturally support more than one major yard. In the author's opinion, the optimum solution would be to use BAE's Clyde yards as the integrator for the Lighter Frigate. Accepting the risk to Type 26 by giving BAE the confidence to invest seriously in their yards and expand the workforce to cope with concurrent builds. The alternative, Cammel Laird, is probably just too much of a leap in the dark at this stage. 

In the end this is about providing the navy with the number of ships it needs to carry out its duties while maintaining a sustainable military shipbuilding sector. 

Oh, and the idea that the UK will export loads of these things is probably bollocks.

Size Matters: Britain's Aircraft Carriers

"The aircraft carrier is truly amazing. I am amazed at the concept of the carrier, and the fact that it works. And it doesn't just work, it kicks butt.

-Lt. Barry W. Hull, VFA-81 Squadron, USS Saratoga, 1991

Why build big? It's a simple question asked frequently about the UK's two new Queen Elizabeth class aircraft carriers. Weighing in at just over 70,000 tonnes they are, by quite a long way, "the largest ships ever built for the Royal Navy". Many have leveled criticisms against them because of their size, claiming they are little more than a vast vanity project, that their size makes them unsuitable for a "medium power" such as Britain and that they reflect a yearning for a status on the world stage that is undeserved. What these criticisms ignore is that there are serious practical reasons why larger carriers are, in most circumstances, a significantly better investment when compared with smaller "pocket carriers" such as the Invincible class ships the UK operated from the late 70s through to 2014; when HMS Illustrious was decommissioned.

Efficiency:
Probably the key reason why larger carriers are significantly better than their smaller cousins is that they are a more efficient way of sustaining air operations from the sea. Generating the same effect with numerous smaller carriers, as some have suggested as a better course for the UK to follow, simply costs much more. The obvious consequence of this is that you get a force of smaller carriers that cannot deliver the same effect as fewer, larger, ships. The reason why this is the case can be neatly summed up with a single word: duplication. This is especially true of the manpower required to run two equivalent carrier forces, equal in "striking power", where the only difference is the size of the ships.  While the individual light carrier will undoubtedly have a smaller crew than an individual large carrier, you might need two or three smaller carriers to achieve the same number of sorties as a single, larger, ship and each still requires a range of highly trained crew members. To draw upon a real-world example: HMS Queen Elizabeth has a core crew of ~679, will carry and operate a tailored air group of 40 aircraft and can surge 110+ sorties a day. In comparison the 25,000t ITS Cavour has a core crew of ~451, an air group of around 20 aircraft and can surge approximately ~40 sorties a day. This means that, broadly speaking, in order to achieve the same effect as a single Queen Elizabeth you need approximately three Cavour-style light carriers on station, with manpower equivalent to double that of the larger ship. When considering the force structure necessary to ensure there are three small carriers available at all times for operations, taking the Royal Navy's current ratio of around 2 ships in maintenance for every 3 ships operationally available, you're looking at a fleet of five light carriers to achieve the same notional operational effect as a pair of Queen Elizabeths. Overall the model of smaller, more numerous, ships would require between 20 and 35% more manpower across the entire carrier force. At a time when the Royal Navy is hard-pressed to man its existing fleet a solution that involves adding up to a third more ship-side manpower to the carrier force is simply impractical and would add substantially to the force's through-life running cost.

As the ships get smaller their efficiency decreases markedly. Concepts for extremely small VTOL carriers, such as the one illustrated below, essentially amount to a reductio ad absurdum but nevertheless prove the point that greater numbers of smaller carriers become exponentially more expensive to produce the same effect in terms of available aircraft and sortie generation. Furthermore, there is also needless duplication in terms of aircraft maintainers with small carriers. It takes a similar number of trained engineers to maintain a small number of aircraft operated from a small carrier as it does to maintain a larger number on a larger carrier, once again duplication of functions across multiple platforms leads to greater manpower needs, reduced efficiency and increased costs across the entire fleet. The cost of the ship per aircraft carried also increases significantly as the platform becomes smaller. Taking into account that the RN, when presented with the opportunity to replace their old carriers, was instructed by the government that no more than two new ships would be procured it then becomes clear that two larger ships were the clear and preferable choice.

Concepts were produced for very small carriers, this modification of the "Type 43" destroyer examined the possibility of operating a pair of STOVL Sea Harriers from escorts. Image courtesy of D.K Brown & Moore's "Rebuilding the Royal Navy"

Sustained Operations:
The next major limitation on many smaller carrier designs is their capacity to conduct sustained air operations. This is due to a number of factors, but principally comes down to aircrew endurance, aircraft maintenance and supply limitations. As you can well imagine it is easier for a carrier with a larger air wing to conduct more sorties in a short-term high-intensity surge effort, however, their advantage becomes even more obvious when looking at sustaining a more modest number of sorties over a longer period of time. Facilities for planning and briefing multiple air operations are also more limited aboard smaller ships. Light carriers with smaller air groups place greater demands on a smaller pool of pilots and other air crew when sustaining operations over time, or compromise by reducing the number of sorties flown. Similarly, working a smaller number of aircraft harder to sustain operations leads to greater wear on individual aircraft, increasing the risk that they end up out of action without an available replacement. For example, during NATO bombing operations in 1995 Britain's "pocket carrier" HMS Invincible was struggling to sustain eight sorties a day with her eight embarked Sea Harrier FA.2s (and both Sea Harrier models had a reputation for being robust and reliable aircraft). A larger carrier with more aircraft embarked can better afford technical problems which prevent some aircraft from operating, because each individual aircraft's availability is less important when a large pool is available to draw from.

Logistics are also another crucial advantage of larger carriers, as greater space for fuel and stores makes them less reliant on frequent resupply operations which take time and prevent flying operations. The Invincible class were (despite some mid-life improvements to the quantity of ammunition they could store in their magazines) always tied very closely to their attendant fuel and stores ships. By comparison the Queen Elizabeth design can hold fuel and stores for around ~400 "strike" sorties, sufficient for five days of very high-intensity operations (defined as a first-day Surge of 110 sorties, followed by 72 sorties a day for four days) before needing to come "off station" in order to resupply fuel and ammunition. Alternatively, a more relaxed tempo could obviously be sustained over a longer period of time. Considering that the Libya air policing mission only required 36 sorties per day to enforce, after the first 11 days spent degrading Libya's air defences, QE could sustain a similar lower tempo operation without resupply for 11 days.

The Invincible class light carriers struggled to sustain air operations for an extended duration without reduced sortie rates and heavy dependence on attendant logistics ships.

Eggs and Baskets:

There is a superficially appealing argument that reliance on a smaller number of larger ships amounts to "placing all of one's eggs into a few very expensive baskets". While this may sound like an enlightened nugget of wisdom on the surface, dig a little deeper and you find that it's a flawed argument. Firstly, "hardening" a carrier force by using a greater number of smaller platforms only works if you have the escort warships to form multiple carrier groups. Without a sufficient number of these ships, which form a vital part of the carrier's layered defences, the available escorts will either be too thinly spread to be effective, or the carriers will have to be concentrated within the protected zone afforded by the available escorts. The first approach risks spreading available forces too thinly, dispersing them into vulnerable "penny packets", while the second only provides marginal benefits over having a single larger ship at the centre of the carrier group. Effective dispersal of the carrier force would multiply the number of effective escort groups required, something that is beyond the current capabilities of the Royal Navy. Secondly, a more dispersed carrier force would also require the dispersal of logistics support ships. As presently planned the UK carrier group will be supported by a large fleet tanker and solid stores ship, in comparison multiple smaller carriers would each require a roughly equivalent number of support ships (and would be more dependent on them, as their own fuel and magazine space would be more limited). If, broadly speaking, three smaller carriers are necessary to replicate the capability of a single larger carrier then the overall force will require something like triple the number of logistics ships and escorts; if the carriers are operated separately in order to take advantage of the dispersed approach. Even then, each group centered on a light carrier will have fewer aircraft available to contribute to the outer ring of its layered defense. This means that Combat Air Patrol (CAP) operations, designed to keep hostile aircraft away from the carrier group, would require a greater portion of the air group's effort and leave fewer aircraft available for offensive operations. What this means in practice is that the smaller carrier would be expending so much effort protecting itself and its escort group that its "punch" would end up being anemic.

The alternative approach to effective dispersal is concentrating multiple smaller carriers within the same group. This does have the clear benefits of not requiring nearly as many additional escorts and also limits the need to duplicate replenishment ships. The group's "punch" is also greater, due to the larger number of available aircraft for all duties, albeit spread between a number of ships rather than concentrated on one. Indeed, the concentrated approach was taken by the commander of the British naval task force that fought the 1982 Falklands War; with HMS Hermes and HMS Invincible operating together throughout most of the conflict. However, it is important to note that this means of employing smaller carriers sacrifices the key benefits of effective dispersal: the increased difficulty of locating the entire carrier force for the enemy, the ability to deploy the dispersed groups to different areas and the increased "coverage" this can provide (especially for anti-submarine operations). It is a fundamental principle of military operations that force be concentrated in order to achieve decisive effects, while a dispersed force may allow individual platforms to survive it is far less useful for striking hard blows against an adversary.

Operating a dispersed force of smaller carriers requires significantly more escorts and logistics ships and must still be concentrated in order to achieve decisive military effects in most circumstances.

Conclusions:
I began this piece with a simple question: "why build big?" and the answer is now clear. When discussing aircraft carriers, from a purely functional perspective, size matters. Setting aside the soft power and symbolic implications of operating large carriers entirely, they're simply better from a pragmatic position. Smaller numbers of larger carriers are more efficient in terms of manpower, cost per aircraft carried and supporting ships than larger numbers of smaller carriers. For the Royal Navy, told that they would only get two ships to replace the remaining Invincible class carriers, the decision was clear and they chose to build two large, efficient and effective ships. This was, for all of the reasons discussed, absolutely the right decision for the UK. The new Queen Elizabeth class, once fully worked up, will be capable of conducting extremely intensive "short and sharp" air operations before exhausting her own supplies of fuel and ammunition or sustaining a lower tempo of operation for a significant time. They will be able to bring a decisive level of force to most engagements, instead of the small "penny packets" of aircraft aboard light carriers. Along with a properly constituted escort group the larger carrier is also capable of simultaneously defending itself and conducting meaningful strike operations when necessary. For those who claim that the UK's large carriers are simple a vanity project I would respond by stating that deliberately pursuing a more expensive and less effective solution, in the form of smaller carriers, because of a perception that they "better suit Britain's position in the world" is not only vain but unnecessarily introspective and downright foolish. When it comes to carriers, the UK has absolutely made the right choice. Bigger is better.

MACs and Jeep Carriers: A Useful Lesson From History

"We must assume that the battle of the Atlantic has begun... Extreme priority must be given to fitting out ships to catapult or otherwise launch fighter aircraft against bombers attacking our shipping. Proposals should be made within a week."

-Winston Churchill, March 6th 1941

At the height of the Second World War Britain, under immense pressure from Germany's U-Boat campaign, converted sixty one merchant vessels into auxiliary aircraft carrying ships. While thirty five were "CAM" ships (Catapult Aircraft Merchantman) equipped with a single last-ditch catapult launched Hurricane fighter, nineteen were fully-fledged flat topped "MAC" ships (Merchant Aircraft Carrier) capable of launching and recovering aircraft. Over the course of the War the Royal Navy also operated a total of forty four light "escort carriers". These ships were made necessary because of a number of factors but, fundamentally, they were built because the RN needed to close the "black gap" (the area in the mid-Atlantic beyond the range of land based anti-submarine aircraft where U-Boats concentrated their efforts). The presence of MACs and escort carriers helped to finally turn the tide in 1943 and ensured that Germany's 1944/45 commerce raiding campaigns would fail.

It's certainly worth asking why these ships were successful in their de-facto service with the Royal Navy, to the extent that it is claimed not a single merchant ship was lost from a convoy defended by a MAC. They certainly weren't very good aircraft carriers, even the largest couldn't operate more than four Fairey Swordfish biplanes and the aviation facilities were quite rudimentary. While escort carriers were certainly better than MACs as aviation ships, some were able to carry up to 24 aircraft and all had superior purpose-built aviation facilities, they achieved substantial tactical and operational effect for the same reason as the smaller civilian conversions. The reason for their success can be summed up in a single word: presence. While the air groups were small, especially when compared with the RN's fleet carriers, the MACs and escort carriers were comparatively cheap and available in large numbers. This meant that they could be used for convoy protection, as well as many other duties that the handful of hard-pressed large fleet carriers were too busy to perform. While around three quarters of the Royal Navy's escort carriers were built in the United States and loaned to Britain under the terms of the Lend Lease act, most were extensively modified by the RN, with all having their provisions for damage control improved and brought up to the RN's higher standards before entry into service.

So, what is the modern relevance of Britain's Second World War experience with MACs and escort carriers? Now we are, of course, no longer facing the threat of hordes of rudimentary diesel-electric submarines attempting to strangle our maritime communications. However, the fundamental lesson learned from that wartime experience was that inexpensive merchant-conversions, and aviation ships that exist below the capability of a fleet carrier, can enhance their larger cousins' availability by covering a wide range of low-end activities. In the Pacific the US Navy used its "Jeep" carriers (escort carriers) for a wide range of support and front-line activities, from transporting aircraft to launching strikes against Japanese forces in support of amphibious operations. While the ships themselves were generally unimpressive this was largely irrelevant, as their fighting power came from the aircraft they carried rather than the ships themselves. What we might now refer to as providing combat capability through "off-board systems".

Skip forward to the twenty first century and we find that aviation ships, below the level of a fleet carrier, continue to be valuable additions to many navies around the world. They come in a vast variety of shapes and sizes and, with modern helicopters, almost any large merchant ship can be converted into a somewhat capable aviation platform "on the cheap". RFA Argus, the UK's floating military hospital, was originally taken up from trade by the MoD in 1982 as the Contender Brezant before being purchased outright in 1984 and into an aviation training ship. She entered service in 1988. In this role she could carry and operate around six RN, Army Air Corps or RAF helicopters up to and including the largest rotary wing aircraft in UK service, the CH47 Chinook. Alternatively she could transport, although not operate, up to twelve Harrier-type VTOL aircraft. In a very real sense Argus, in her "aviation training" configuration, was the modern embodiment of the MAC ships of the Second World War. Her initial conversion proved extremely cost effective, costing only £45mn (~£120mn in 2016 prices). She also had the added benefit of only requiring a fifth the manpower of an Invincible class light carrier, just over half of which were actually Royal Navy personnel; with the rest being made up of RFA merchant sailors.

RFA Argus, the "modern MAC", has proved to be an incredibly valuable asset 
over nearly three decades of hard service.

Since her formal entry into service with the RFA in 1988 Argus has consistently been a busy ship. During the 1990-91 Gulf War she received her second major conversion, adding extensive medical facilities to enable her to act as the UK "Primary Casualty Receiving Ship" (or PCRS). She sailed or the Gulf with four Sea-King helicopters embarked, which aided in mine-clearance operations once she arrived in theater. In 1992 she deployed to the Adriatic, again with Sea Kings embarked, in support of the UK's contribution to the UN Protection Force in Yugoslavia. In 1997 she deployed to the West coast of Africa to evacuate UK nationals from the Congo. She was part of the UK's national amphibious task group that deployed to both Sierra Leone in 2000 and Iraq in 2003. She underwent a major life extension in 2009 before being deployed to the Mediterranean, ready to evacuate UK nationals from Libya in 2011. Later that year she was assigned to the counter-piracy effort in the Gulf of Aden. Her most recent activities have included support for UK overseas territories in the Caribbean and aiding in the fight against Ebola in Sierra Leone.

It is notable that Argus, like the Second World War MAC, has filled the gap that exists below the space occupied by high-end aviation platforms designed for intensive war fighting. Indeed, the only time that Argus was trialed in such a role (she was used as a makeshift helicopter carrier during the international intervention in Yugoslavia) she did not perform well. However, as an auxiliary aviation support platform, used initially for training and later for a range of defence and security activities below the level of war, she has proved herself invaluable. Indeed, it's possible that the lessons learned from RFA Argus contributed to the development of the Bay class auxiliary landing ships, with their distinctive flat aviation decks aft of the main superstructure.

When her procurement, conversion and operational costs are tallied and compared to her service record it becomes quite clear that Argus has been, and continues to be, excellent value for money. She is the ultimate vindication of the relevance of the MAC concept for the 21st century. Considering this, it is concerning that the UK government has refused to specifically state whether she will be replaced with a similar platform after she leaves service in 2024. The loss of Argus without replacement in order to save money would, in the author's view, be a profoundly short-sighted decision. Considering how relatively cheap such a platform would be to purchase, convert and run, as well as the enduring utility of aviation platforms that can fill the sub-war fighting niche, the prudent choice would be to opt for a replacement with similar capabilities.

If RFA Argus has epitomised the enduring viability of the MAC concept for the RN in the twenty first century, then HMS Ocean has demonstrated that the fundamental guiding design principles of the WWII escort carrier still also hold relevance. Built for only £154mn in 1993 (£280mn in 2016) her construction costs were about the same as a Type 23 frigate, or less than a tenth the cost of a Queen Elizabeth class strike carrier. In order to achieve the low-cost she was built to reduced part-commercial standards and sacrificed other in other areas compared to a "full fat" fleet unit. She is limited by her inability to achieve high sprint and cruise speeds, has a relatively minimal self-defence armament and a noticeably shorter lifespan than ships built to full military standards. In exchange for these trade-offs the UK received a capital-size ship at a very low cost that was rapidly built and commissioned in four years.

While originally conceived of and built as a Landing Platform Helicopter (LPH) to support Royal Marine amphibious operations she, like Argus, has proved useful for a wide variety of rotary-wing aviation tasks. From her support of the UK intervention in Sierra Leone in 2000 and the RM invasion of the Al Faw peninsula during the 2003 Iraq War in her intended LPH role to acting as a makeshift "strike carrier" with Army Apache helicopters embarked during the 2011 Libya intervention. Since 2010 she has repeatedly led the UK high-readiness Response Force Task Group on its annual "COUGAR" deployment and acted as an auxiliary heliport, moored at Greenwich, during the 2012 London Olympics. As of June 2015 she is currently serving as the RN's flagship. It is expected that she will decommission in 2018, nominally replaced in the LPH role by HMS Prince of Wales.

HMS Ocean in the light strike role, with Army WAH-64 Apache attack helicopters
embarked.

Ocean, like Argus, the Second World War MAC and the escort carrier continues to demonstrate that "second rate" aviation ships are not only a viable concept, but continue to fill essential niches that large strike carriers do not sit comfortably in. Ultimately the use of a 70,000 ton supercarrier to conduct HADR operations with its aviation assets will, in most circumstances, be a waste of one of the RN's most potent war-fighting assets. Similarly, placing a Queen Elizabeth class close enough to shore to act in the LPH role places an extremely high value asset at heightened risk of attack. In both circumstances a simple and cheap aviation platform is a far more appealing prospect, leaving the "proper" carriers available to deploy at short notice to do what they're best at: deterring and defeating serious threats to national interests.

Over the last two decades Ocean and Argus have acted as an effective adjunct to the UK's front line carrier fleet, made up of two Invincible class light ASW/strike carriers for most of these ships lives, they have performed essential auxiliary and supporting roles that freed up the fixed-wing carriers for other, more important, duties. It is a great shame that Ocean will not be replaced with another cheap LPH, she has added great value to the Royal Navy over her relatively short life. However, there remains hope Argus may yet be replaced with a similar auxiliary aviation platform. Failure to do so would almost certainly heap additional burdens onto the strike carriers and waste some of their awesome capability. Just like our predecessors concluded during the Second World War, if we are to make the most of our fleet carriers we need to invest in the auxiliary aviation platforms necessary to support them, allowing them to go where they need to be; rather than tied up with duties for which they are poorly suited.

Trident, Vanguard and Successor: A Guide to the British Deterrent

As the date of the main gate decision on "Trident" edges ever closer the debate on the UK's nuclear deterrent has intensified. Heated arguments have flown back and forth between those who see renewal as necessary and those who disagree strongly with it on ethical, financial and practical grounds. While it's a positive sign that the debate has been conducted in the public sphere, to a much greater extent than most defence issues, there remains a great deal of misinformation and confusion surrounding the specifics and the terminology of "Trident" renewal. Unfortunately, while there are a few exceptions, the reporting of defence issues by the major public outlets is often patchy, biased and sometimes downright inaccurate. In this piece I hope to address the specifics of the system colloquially known as "Trident" and provide the facts (along with some context) on renewal, along with some of my own views on the key issues and misconceptions that surround the nuclear deterrent. Rather than engaging in the moral arguments surrounding nuclear weapons this piece is purely designed to address the technical issues, as well as some of the less than accurate public and media perceptions of the deterrent.

The Vanguard Class:

Britain's nuclear weapons are currently carried aboard the four submarines of the Vanguard class, operated by the Royal Navy. The entered service between 1993 and 1996 and are the largest submarines operated by the UK. At just under 16,000 tons submerged they're roughly twice the size of the Astute class nuclear powered attack boats and three times the size of the older Trafalgar class submarines. Each boat has a compliment of ~135 Officers and Ratings, but has twice that number assigned to it, forming two full ships companies referred to as the "port" and "starboard" crews. This ensures that the deterrent boat will never be prevented from sailing due to illness or injury amongst critical members of the team needed to run the boat, as there are always spares available. While one crew is deployed the other will either be on leave or in training. In order to provide "Continuous At Sea Deterrence" or CASD the four submarines rotate, with one armed and deployed in an undisclosed location, one in training and preparing to deploy, one undergoing short term repairs and one in deep refit. In this way there has always been one nuclear-armed British submarine at sea at all times since patrols began in April 1969. Following on from their predecessors the Vanguard class operate from HM Naval Base Clyde, sometimes referred to as Faslane.

The Vanguard Class are officially referred to as SSBNs (which stands for Ship, Submersible, Ballistic, Nuclear) meaning that they are not only powered by a nuclear reactor but also carry nuclear-armed ballistic missiles. The class are powered by the Rolls Royce PWR2 nuclear reactor, enabling the submarines to remain underwater for months on end, limited only by food supplies for the crew. Each Vanguard class submarine can carry up to sixteen Trident II D5 ballistic missiles. However, due to the UK's participation in multilateral arms reduction since the end of the Cold War they're now believed to routinely sail with only eight. The Vanguard class also carry conventional torpedoes for self-defence against other submarines and surface ships. Construction of the four Vanguard class submarines cost the UK around £15 billion, just over £1 billion a year spread over twelve years from the keel of the first boat being laid in 1986 to the completion of the fourth and final boat in 1998. Although the boats have an expected lifespan of twenty five years, a substantial life-extension programme will enable them to serve an additional ten to ensure a seamless transition from the Vanguard class to the "Successor" submarine class.

Key Issues and Misconceptions:

-Although the mainstay of Britain's nuclear deterrent has been provided by "Continuous At Sea Deterrence" for almost a half century now, some believe the operation of the four deterrent submarines imposes a serious burden on the Royal Navy. Of the roughly 4,000 Officers and Ratings of the submarine service around a quarter or more are likely assigned to the deterrent submarines. In addition a frigate, attack submarines and submarine hunting aircraft are needed to protect the deterrent boat as it enters and leaves the Royal Navy's base on the Clyde.

-Some commentators have described the CASD system as a leftover from the Cold War, unsuited to a world where Terrorism and cyber warfare will become the real threats in future. However, with an increasingly aggressive Russia modernising its own nuclear forces, others would suggest that the system still remains relevant to today's problems as well as providing insurance against unexpected future threats. While both arguments have some merit, it is interesting to note that all other nuclear powers either possess, are renewing or are pursuing a submarine-based deterrent. The broad perception abroad seems to be that submarine-launched ballistic missiles are both relevant and a credible means of deterrence.

-While it has been claimed that the boats might be vulnerable to some form of cyber attack it is doubtful that this is actually the case. The deterrent submarines operate a closed computer system, so any would-be attacker would have to actually get on-board and introduce such a computer virus manually. The development of software that could attack the submarine's vital systems would also require in-depth knowledge of the system in the first place, something that a hostile state or terrorist group would find all but impossible to acquire. Even then, as with most RN vessels, the submarine will have manual and analogue back-up systems should the computerised primaries fail. All told it would be almost impossible to conduct a successful cyber attack on the existing nuclear deterrent submarines.

-In the last few years there have also been a spate of articles expressing concern about the safety of the submarines, citing hundreds of accidents as well as tens of fires, equipment failures and "nuclear incidents" on board as evidence of a profoundly unsafe system. However, taken at face value and without any context these figures can be extremely misleading. For example: while it's true that fires occasionally occur on all Royal Navy warships, almost all are extinguished within seconds of breaking out. Even in the event of a serious fire, the Royal Navy rightly maintains some of the highest standards in the world when it comes to firefighting and damage control (having thoroughly learned the lessons of the Falklands War). As for "nuclear incidents", none of the twelve "Category B" events that have occurred since 2009 threatened the release of nuclear material into the environment or atmosphere. Nor did they endanger workers or the public. As it stands, a Category B incident is defined as: "actual or high potential for a contained release [of radiation] within building or submarine or unplanned exposure to radiation". According to the Ministry of Defence, most of these incidents were minor.

-There is also a misconception amongst some less well informed observers that because all UK submarines are "nuclear" they all carry nuclear weapons. This is not the case, Britain currently operates two separate types of submarine: the four nuclear armed SSBNs of the Vanguard class and the seven nuclear powered but conventionally armed SSNs (Ship, Submersible, Nuclear) of the Astute and Trafalgar classes. While all UK submarines are powered by a nuclear reactor, only the four boats of the Vanguard class carry ballistic missiles and nuclear weapons.

The "Successor" Submarines:

The "Successor" submarine is intended as the replacement for the existing Vanguard class, with the first boat expected to enter service in 2028. The class is expected to have a service life of around thirty years, with the fourth boat likely to operate well into the 2060s. Unlike the Vanguard class the Successor will have four fewer ballistic missile tubes, a total of twelve rather than the Vanguards' sixteen. These tubes will be a shared design with the US Navy, who are looking to start replacing their Ohio Class ballistic missile submarines within a similar time frame. Each "Common Missile Compartment" will contain four launch tubes, Successor will have three such compartments, whereas the American SSBN-X (their next generation ballistic missile submarine) will have four or more. This will enable the UK and US to pursue a common replacement for the Trident II D5 missile when it goes out of service in the 2040s. As it stands the government's current intention is to maintain the number of missiles (eight) and warheads (forty) carried by the Vanguard submarines with the transition to Successor. In 2011 it was agreed that the Successor submarines would use the Rolls Royce PWR3 reactor, an "Anglicised" version of the US Navy's latest design. The new reactor is expected to be safer and cheaper to maintain over the boats' thirty year lifespan, when compared with the PWR2 that currently powers the Vanguard and Astute classes.

As it stands, little concrete information exists in the public sphere beyond relatively broad specifications and a few concept images (like the one shown above). However, from historical precedent and educated guesswork we can safely assume that the Successor boats will be significantly quieter than their predecessors, just as the Astute class are markedly quieter than the Trafalgar class that came before them. Like the Vanguard class they will also carry conventional torpedoes for self-defence. It seems unlikely that the relatively successful dual-crew system would not be carried over to the new deterrent submarines.

Key Issues and Misconceptions:

-A few people have also claimed that the ballistic missile submarine will soon be made obsolete by underwater drones, and other unmanned systems, that can listen for and detect submarines and unmanned aircraft that are currently being developed. They argue that the Successor class would be hopelessly vulnerable to such systems, as it would lose its ability to hide. These commentators forget that these technologies are far from new, during the Cold War NATO erected vast arrays of fixed hydrophones to detect Soviet submarines in the North Atlantic, and certainly not foolproof. With every generation submarine detection equipment has become more sensitive, yet the boats continue to get quieter in response. Each measure developed to detect the submarine is met with a countermeasure in response. Not only have the boats changed beyond all recognition since their primitive beginnings at the turn of the twentieth century, but so have the tactics employed to hide them. Examining the lessons of history it seems unlikely that a single innovation in anti-submarine warfare will, at a stroke, render the submarine obsolete.

-There appears to also be a presumption that the Successor submarines are extremely expensive, as they form the biggest chunk of the expenditure necessary for the renewal of the UK's nuclear deterrent. There is also a perception that the programme costs have increased significantly since it was first announced in 2007. However, much of the apparent increase in the cost of replacement has been due to inflation. The 2006 defence white paper on the issue laid down an estimated price of £15-20bn for the whole nuclear renewal programme,most of which would be the cost of the new submarines. When adjusted for GDP inflation to match 2014 prices the "cost" rises to between £17.5 and 23.5bn for the whole programme. While the higher figure closely matches the "between £20 and 30bn" price-tag stated by the government, it may also have been stretched to encompass costs previously not included, such as through-life expenditures, decommissioning and safe disposal of the boats and their nuclear reactors. On top of this the Treasury has added a £10bn contingency fund, the purpose of which is somewhat opaque; but could conceivably be the government hedging against a second Scottish referendum (and the need to reconstruct facilities elsewhere) or simply prudent management to ensure the delivery of a critical defence equipment programme.

-There is also a view that the cost of the Successor submarines, the major expense involved in renewal of the nuclear deterrent, could easily be transferred to bolster the UK's conventional forces that have been run down over a long period of time. However, upon close examination of the issue the issue is far more complex than many realise. Firstly the shortfall in work for the nuclear submarine construction facilities at Barrow in Furness would have to be made up with a substantial order of more Astute class nuclear-powered attack submarines. Likely more than five boats costing £750 million each, so many more conventionally armed submarines would likely impose through-life costs and crew requirements similar to the nuclear deterrent boats that they would replace. It is likely that we would eventually end up having to build two classes of conventionally armed, but nuclear-powered, submarines in order to sustain the design and industrial base necessary to continue producing attack submarines. The cost of safely decommissioning the nuclear weapons facility at Coulport would also be very substantial and eat into any short-term savings made. Also to be considered is that, in the event of Trident cancellation, some or all of the money saved would inevitably be siphoned off by the Treasury and redirected into other areas of government (as many anti-nuclear figures argue should be the case) such as: health, education, welfare etc... It is by no means clear that cancelling the successor submarines would lead to a substantial re-investment in conventional forces and would almost inevitably impose significant second-order costs. While long-term savings would indeed be made, it would not be the panacea for either conventional defence, or other areas of government spending, that some make it out to be.

The Trident II D5 Submarine Launched Ballistic Missile:

The UGM-133 Trident II, or Trident II D5, is a Submarine Launched Ballistic Missile (SLBM) with a range of more than 7,500 miles and a payload of up to twelve nuclear-armed Multiple Independently-targetable Re-entry Vehicles (MIRVs). The missile first entered service with the US Navy in 1990 and later with the Royal Navy in 1993 when the first of the Vanguard class submarines entered service. Unlike conventional and cruise missiles the Trident II D5 leaves the earth's atmosphere for part of its trajectory, acting like a multi-stage rocket, before its warheads return to earth and strike their targets. The missile is principally guided by an on-board astro-inertial guidance system, that can be supplemented by GPS to increase its accuracy. From what is publicly available this system takes account of the submarine's relative position to its target and uses a fixed object (in this case a star) as a reference point to guide the missile onto its target. At present the UK leases 58 of these missiles from the United States, which are drawn from a common pool shared by the US Navy's Atlantic SSBN squadron. Unlike its predecessor, Polaris, the missiles are not serviced in the UK but at the Lockheed Martin plant in King's Bay Georgia along with the US Navy's missiles. 

Key Issues and Misconceptions:

-While the recent discussion on the subject of the British nuclear deterrent has been framed as the renewal, or replacement, of Trident; in fact the Trident II D5 missile is set to remain in-service with the Royal Navy and US Navy into the 2040s. It is one of the few components of the overall system that, while it will receive a substantial life extension, will not be replaced for many years to come.

-Often the most contentious arguments over the UK deterrent relate to its independence from the United States, specifically the degree of operational control that the Americans could exert over the British system. Firstly, it is necessary to clearly state that the US do not possess a "kill switch" that would render the UK's missiles inert or would prevent them from being fired. As the US Navy's own missiles are of the exact same design, drawn from the same pool as the UK's, such a safeguard (if it existed) would therefore also render a major component of their own deterrent useless. Nor does the US government possess the ability to remotely destroy the missiles once launched, such a system would open their own deterrent up to being disabled by a potential enemy, should they steal the means of "self-destructing" the missiles. The system is designed so that, short of being actively shot down, once released the missiles cannot be stopped. There is also the suggestion that the US could simply "turn off the GPS", even if it were as simple as those that claim this make out; disabling the GPS would simply make the missiles marginally less accurate. Their primary means of guidance, the astro-inertial star sight system, is designed to function without input from GPS. The retention of this older system is likely deliberate, as it prevents the US/UK deterrent from being disabled by an attack on the American GPS satellite network. While the US could withhold gravitational data and weather reports over the intended target area, this would simply degrade the accuracy of a British nuclear strike and would not be able to prevent it. For all intents and purposes the UK deterrent is Operationally Independent: meaning that the US have no means to stop the UK from conducting a nuclear strike, short of shooting down the British missiles.

-With respect to the independence of the system it is true that should the US decide to withhold access to its missile servicing facilities it could eventually render the UK's Trident II D5 missiles unusable. According to Parliamentary estimates his would likely take many months, if not a year or more, to achieve. However, given the UK's extremely close relationship with the United States and the existing unprecedented level of co-operation in the field of nuclear weapons and delivery systems the chance of this actually happening would best be described as extremely remote. At the least it would require a severe political break between the UK and US, significantly worse than that which occurred during the Suez Crisis. In the author's opinion, this remains extremely unlikely and the US will almost certainly remain a highly dependable partner in this field. This is not least because the joint submarine deterrent using the Trident missile strengthens the American nuclear guarantee of Europe significantly. Fundamentally it ensures that a potential enemy could not tell a British attack from an American one, this means that Britain could force a general nuclear exchange with the United States if the US were to renege on its commitment to the defence of Europe during a crisis. This inextricably ties the American strategic deterrent to the defence of Europe, something the US are very much aware of and value.

-There have been plenty of commentators keen to express the obsolescence of the Trident missile system, describing it as a "Cold War relic" designed to destroy Moscow and St Petersberg. While there is a grain of truth at the heart of this argument, it too is misleading. The British deterrent was, at the time of the Cold War designed around the so-called "Moscow criterion". In short this was the requirement that the British delivery system be able to penetrate the defences around the Soviet capital and conduct a successful nuclear strike against it. Initially this meant that the RAF's V-bomber force was equipped to break through Soviet air defences in order to reach their targets. However, as Soviet defences improved it became clear that air-launched weapons (even primitive cruise missiles like the RAF's Blue Steel) would not be sufficient. So the UK turned to submarine launched ballistic missiles: first Polaris, then an improved version of Polaris codenamed "Chevaline" and later Trident. These improvements all ensured the UK could respond to aggression with an assured response, capable of penetrating even the most sophisticated integrated air and missile defense system in the world. The "Moscow criterion" remains relevant because, if the UK can be sure of its ability to carry out a successful nuclear response against the most heavily defended target in the world, then it can be sure of a successful nuclear response anywhere else. This strengthens the deterrent power of the overall system, because crucially it remains highly credible in all circumstances.

The W76 Nuclear Warhead:

After the retirement of the RAF's remaining WE.117 air-dropped nuclear bombs in 1998 the W76 became the only warhead in service with the UK armed forces. It is believed to be an "Anglicised" copy of an American design, although the details of its internal components are mostly classified. What is known is that the warhead sits within the conical Mk. 4 re-entry vehicle (a mock-up of which is pictured above). With a declared maximum yield of 100 kilotons of TNT the W76 is around seven times more powerful than the Atomic bomb dropped on Hiroshima at the end of the Second World War. However, some sources indicate that the UK's possesses weapons with a variable yield, down to as low as 10 kilotons, in order to provide decision makers with a more flexible and proportionate nuclear response (if such a thing exists). Between one and twelve warheads can be carried by each Trident II D5 missile. It is believed that the 40 deployed warheads are spread unevenly amongst the eight missiles carried aboard the deterrent submarine. These are believed to be mixed with dummy warheads, decoys and penetration aids in order to ensure the success of a UK strike conducted against an area protected by a sophisticated missile-defence system.

The UK's warheads are designed and manufactured at the two Atomic Weapons Establishment (AWE) facilities at Aldermaston and Burghfield. There is a high degree of collaboration with the US' counterpart facilities at the Los Alamos site in New Mexico and the Sandia & Lawrence Livermore laboratories in California. The UK's weapons are also stored at the Royal Naval Armament Depot (RNAD) at Coulport, which is jointly run by a subsidiary of AWE and Lockheed Martin, where they are mated with the Trident II D5 missiles and loaded onto the deterrent submarines. Although the UK continues to refuse to release the exact details of its nuclear arsenal, it is believed to possess a total stockpile of 225 weapons, with around 160 of those being operational at any one time.

Key Issues and Misconceptions:

-Some have questioned the independence of the UK's deterrent on the grounds that the AWE uses a number of "off the shelf" components, procured from the United States, in Britain's nuclear weapons. According to a report submitted to Parliament these include: the firing mechanism, Neutron generator, gas reservoir and Mk. 4 re-entry vehicle. While it is true that Britain would find it difficult to immediately source replacements if the US chose to withhold these components, it would be well within the UK's capacity to manufacture them. As the AWE possesses the full designs for the W76 warhead, creating native versions of certain components wouldn't be prohibitively difficult; if the commitment was made to continue with the deterrent under such circumstances. However, as with the withholding of support for the UK's Trident II missiles, the likelihood of the US actually doing this remains extremely remote.

-There have also been questions raised, notably in Parliament, about the possibility of dangerous nuclear emissions from RNAD Coulport. According to data released by the Ministry of Defence emissions were well within the safety limits set by both the MoD and the Scottish Environment Protection Agency (SEPA) between 2009 and 2012. For comparison, in 2012 the Hunterston B civil nuclear power station discharged around 370 times the Tritium gas of RNAD Coulport, while still being within the safe limits set by SEPA. The emissions from the nuclear storage facility can be considered so small in comparison as to be negligible, posing no health risk to those living on or around the facility.

-Also of concern to some is the vulnerability of the UK's nuclear weapons to seizure by terrorists, especially considering that they're transported by road between AWE Aldermaston and RNAD Coulport. However, it must first be stated that successfully intercepting and seizing a warhead from one of these convoys would require a level of intelligence gathering and combat capacity beyond any militant group currently operating on the British Isles. Not only are the times and routes of these convoys national secrets of the highest order, revealed only to regional police forces hours before the convoy moves through their jurisdiction, but they are also extremely heavily guarded. Not only does each convoy have a range of civilian emergency teams to deal with any contingency, from safety experts to firefighters, but it is guarded by armed Ministry of Defence Police officers of the Special Escort Group, and likely also special forces personnel. Each convoy is continuously tracked by the police and is in constant radio communication with support forces should an incident occur. Successfully plotting an attack on one would be nearly impossible, something reserved more to the pages of a Tom Clancy novel than reality.

-Some may also worry that the weapons themselves are inherently unstable and dangerous, threatening to trigger a nuclear explosion at any moment should somebody make a mistake. This is categorically not the case, the bomb itself is built to do a very specific thing: evenly compress the core of nuclear material (likely highly enriched Plutonium in the case of the W76) until it reaches the critical point at which a chain reaction occurs and causes a "nuclear explosion" as we know it. In order to achieve this, the device uses explosives precisely placed around the core, and crucially: detonated at the same instant. On two occasions during the early years of the Cold War US aircraft armed with nuclear weapons crashed, unevenly detonating the explosives in their nuclear weapons. Instead of causing a nuclear explosion it merely shattered the core and spread toxic plutonium dust over a small area. Even in the worst-case scenario, a nuclear weapon exposed to the extreme shock of an air crash followed by an explosion, the weapons didn't explode. Unlike some conventional explosives nuclear material will not explode if dropped, burned or exposed to an uneven explosion. Thankfully nuclear weapons are almost impossible to inadvertently detonate.


There you have it, a reasonably examination of the technical details of the UK nuclear deterrent, addressing some of the issues raised in the recent debate and some of the popular misconceptions about the UK's nuclear forces. Hopefully by collecting a broad range of information in one place I can help contribute, in some small way, to improving a debate which is too often mired in inaccurate perceptions.

After Type 26: The Royal Navy's Next Generation Frigate

"We will also launch a concept study and then design and build a new class of lighter, flexible general purpose frigates so that by the 2030s we can further increase the total number of frigates and destroyers. These general purpose frigates are also likely to offer increased export potential."

-SDSR 2015

The UK's 2015 Strategic Defence and Security Review brought a few surprises for those with an interest in the Royal Navy's future equipment programme. The review suggested that the Type 26 programme be capped at 8 hulls, rather than the 13 originally planned, and is to be followed by a class of at least five, but possibly more, lighter general purpose frigates. Commentators have already begun speculating about the meaning of the phrase "lighter, flexible general purpose frigates", with some suggesting that it means the RN will be getting a class of corvettes or lightly armed frigates. In the author's opinion this seems unlikely, for many years the RN's leadership has placed a great amount of stress on the credibility of it's surface escorts as platforms for intensive war fighting first and foremost, with other less demanding tasks coming second. It is difficult to believe that the service has made a radical change in this regard, as First Sea Lord Zambellas has continued to underscore the value of capable and credible warships. That said, it does not take the construction of a platform as comprehensively capable as the 8,000 ton cruiser-like Type 26 to produce a useful first class warship. Indeed, the current 5,000 ton Type 23 frigates have done sterling service, in both high and low threat environments, since HMS Norfolk commissioned in 1990; and were successfully built in very significant numbers: 16 in total.

Before we can begin any discussion about what the next generation frigate could look like, it's role and place within the RN's future fleet needs to be defined. The fleet of the 2030s will look quite different from the one the UK is currently used to: it will be centered on a high-readiness carrier battle group and a lower readiness amphibious group, both supported by escorts as well as other specialist shipping. Alongside the escorts required to support both of these groups, UK frigates and destroyers will almost certainly also have to provide a number of detached vessels to provide presence in areas considered important to national interests. These currently include, but are not limited to: the Falkland Islands, Persian Gulf and West Indies. Of these standing patrol tasks only one, the Persian Gulf, is likely to require the continuous presence of one or more of the UK's most capable warships. This almost certainly means the deployment of either Type 26 or Type 45. The Falklands patrol task would be suitable for the new GP frigate, as it requires presence and some capability to demonstrate the UK's enduring commitment to the Islands but the threat level is relatively low. As for the West Indies, in the author's opinion this tasking would ideally be covered by one or more forward based OPVs and one of the RFA's Bay Class LSDs, for disaster relief in the hurricane season. Occasionally an ASW frigate could be rotated into this region, for counter narcotics and to train submarine hunting in tropical conditions, but this would be when ships are not required for other essential tasking. With this in mind, it seems likely that the lighter frigate would spend most of its time in low to medium threat environments when deployed alone and would likely engage in high-intensity war fighting activities as part of, or supported by assets from, one of the RN's task groups.

The future frigate fleet could easily be compared with the RN's pre-2010 force structure. The large and highly capable Type 26 would act as a direct successor to the general purpose Batch 3 Type 22s, able to embark a command staff in order to act as the lead ship for a task group of British and/or allied escorts. 72 missile tubes, Artisan and Sea Ceptor give it a formidable armament for self protection and localised air defence. Type 26 will also act as the principal ASW escort for the Carrier and Amphibious groups, as it will almost certainly be the only class equipped with the 2087 towed array sonar and it's eventual replacement. With the very high end task group escort roles covered by Type 26 and Type 45 the "lighter frigate" need not require complex air defence or ASW equipment beyond that required for credible self-defence. I would suggest that these ships be specialised to some degree in favour of a certain niche capability, rather than simply being a less well equipped version of the Type 26.

While there are several concepts for differently configured ships I wish to explore later, there are a few common systems that the author considers necessary for the new frigate, if it is to be a credible platform able to operate in both high and low threat environments:

CODLAG/CODLOG propulsion: A proven and reliable system, unlike IEP used in the Type 45, with a good balance between sprint speed, reliability, noise, and fuel efficiency when cruising. The system could be a direct copy of the power plant from either the Type 23 or Type 26 if it would reduce costs.

5" Gun: Generally useful for shore bombardment and a range of low intensity constabulary activities. 5" will be the RN standard once Type 26 enters service, mounting a different calibre gun and introducing a whole new logistical support structure for it would be costly and offer few benefits.

Type 997 Artisan Radar: A modern and capable system which is soon to be the standard across the RN; with sets planned for the Type 23 and 26 frigates, Queen Elizabeth Carriers and Albion LPDs. Fleet wide commonality and a long production run should help keep costs down.

Sea Ceptor: In order to be able to operate alone the frigate needs, as a bare minimum, the ability to defend itself against attack by aircraft and anti-ship missiles. Sea Ceptor offers this minimum credible self defence capability and will be a common and proven system throughout the escort fleet once the Type 26 programme is complete.

Seaboats: facilities for operating two of the RN's existing Arctic 28 or Pacific 22/24 RIBs.

Countermeasures: A carbon copy of the RN standard, currently Seagnat, to exploit the benefits and cost savings of fleet wide commonality.

All the concepts below are envisioned to be in the 5,000-7000t range. Although much of what follows is speculative and oversimplified I intend it more as the beginning of a conversation on some of the options the RN has for it's post-Type 26 frigate.

The Type 81 "Tribal Class" General Purpose frigate HMS Eskimo

Type 83:
Drawing upon the legacy of the Tribal and Duke class general purpose frigates "Type 83" would be a frigate in the 4-5000 ton range with a broad, but shallow, general purpose equipment fit. These ships would be well suited to constabulary tasks where long range endurance, or increased threat, is a factor and OPVs would therefore be unsuitable. A modern armament would also allow them to operate in areas where the threat of attack from state actors or modern weapons systems is also present. In areas where the threat of such an attack is high these vessels could be deployed in pairs, to provide similar AAW and ASuW capabilities to a single Type 26, or as escorts for a carrier or amphibious task group.

As for the armament, twenty four Sea Ceptor and eight strike length Mk. 41 Cells would be a good place to start. As previously discussed Sea Ceptor is a highly credible system ideal for self and point defence, that will come with the major benefit of fleet wide commonality. It will also have been proven on the Type 26. The strike length Mk.41 cells would offer flexibility and access to the next generation of anti-surface and cruise missiles, ASROC could be used but the other options would probably be better suited to the ship's intended role. As a truly general purpose vessel the class would need ASW fit beyond the bare minimum torpedo defence system mentioned earlier. Therefore "Type 83" would include a bow-dome mounted 2050 sonar set, five of which could be salvaged from the last Type 23s in order to equip the new frigate class, assuming that the Type 26 will take the first eight sets. If this is not feasible then an alternative system with similar capabilities would need to be procured.

Aviation facilities would be a hangar and landing pad, able to accommodate a single Wildcat helicopter or smaller rotary wing UAVs. For a general purpose frigate a utility helicopter, such as Wildcat, is invaluable for surveillance, constabulary duties, ASW and surface strike.

The Type 23 frigate HMS Northumberland

Type 27:
Inspired by the excellent think defence article that can be found here, as well as the original concept for the Type 23, "Type 27" would be a dedicated task group towed array ship. The proliferation of quiet diesel electric submarines looks set to be a major impediment to the UK's ability to project power into the littoral in the coming years. Protecting the UK carrier and amphibious task groups against this threat will require more than a single Type 26 defending the group's capital ships. "Type 27" is conceived with area anti-submarine operations in mind. Its purpose would be to operate at some distance from the task group, screening it from underwater threats. Such a class, being more expendable than Type 26, would also be better suited to operating up-threat in the littoral against hostile submarines. Such operations may become an increasingly necessary preceding step before other activity can be conducted in the littoral zone. The weaknesses of the concept lie in the specialist nature of such a design, admittedly it would mainly exist to free up Type 26: the ship best suited to general purpose and lone cruiser operations.

Once again twenty four Sea Ceptor cells should be sufficient to provide adequate self defence capability against air attack and anti-ship missiles. These ships, as dedicated ASW platforms, would need to be equipped with both 2050 (or equivalent) bow dome and 2087 towed array sonars. Accepting that Mk.41 and ASROC would be prohibitively expensive, offensive action against underwater threats would have to be performed by the embarked helicopter. While Stingray torpedo launchers would be a useful addition for last ditch self-defence they are not a necessity, and could easily be omitted in order to reduce costs. Aviation facilities would have to be suitable for a single embarked helicopter. The hangar and landing pad would have to accommodate an aircraft up to the size of a Merlin.

A Japanese Shirane class helicopter destroyer

Type 63
The Royal Navy has a wealth of practical experience which demonstrates the immense value of rotary wing assets, for all manner of operations at sea. From counter piracy and disaster relief to surface strike and anti-submarine warfare, helicopters are valuable assets with a great deal of utility. To date almost all dedicated helicopter destroyers have been specialist anti-submarine warfare vessels. The RN's only experience with such ships was with the Tiger Class cruisers in the 1970s, after they were converted to carry Sea King helicopters. More recently both the Italian and Japanese navies have operated destroyers and cruisers in the 5-7000t range, optimised for helicopter operations. With the RN's current helicopter carrier, HMS Ocean, is slated for disposal in 2018 the need for a new class of helicopter carrying ship, capable of supporting amphibious operations, is apparent. While one of the intended uses of HMS Prince of Wales may be to act as a very large LPH, supporting amphibious operations, she will remain a very high value asset. There will inevitably be times where the risks inherent in putting her close to shore become unacceptably high. Nor can the UK's single large LPH be in more than one place at a time. The ability to sustain an ensuring presence for counter piracy, disaster relief or maritime interception operations with a light helicopter destroyer would be highly useful. In a high intensity war these ships could take on the more traditional role of supporting anti-submarine helicopters.

The ship wouldn't require more than 24 Sea Ceptor cells for self defence. Underwater protection would be minimal, a tried and tested commercially available military sonar would suffice. A very large portion of the deck space would need to be devoted to a very large hangar and helicopter deck, suitable for operating up to four Merlin or Wildcat aircraft. If the hangar can be made large enough, there would also be the possibility of accommodating a single Chinook with unfolded rotors. If the aim is to increase the utility of the ship by allowing the RN to tailor the air group to the specific task then the widest range of helicopters, and eventually unmanned rotary wing UAVs, need to be operable from the ship. In this case a simpler but larger ship could be justified, as fewer complex systems would hopefully help to keep costs manageable.

The Damen Sea Axe 1800 OPV, with a large multi-mission bay

Type 84
A major development of the Type 26 design is its mission bay, designed to accommodate a range of equipment from additional sea boats to air, surface and sub-surface unmanned vehicles and ISO containers. Depending on how quickly these systems mature they could soon play an increasingly significant role in maritime operations. Type 26 has, rightly, been equipped with the mission bay and space to operate a range of future systems currently under development. The potential of unmanned  systems is already being tapped with the Hazard boats and their mine countermeasures drones. In future these systems are intended to be operable from a range of surface combatants, including frigates. The US Navy is also exploring the potential of sub-surface drones for anti-submarine warfare. It is entirely plausible that some of these systems will have moved out of the development phase and into service by the time the next generation frigate begins construction in the late 2030s. Similar to the helicopter destroyer the ship itself would be able to stand-off outside the littoral, away from certain threats, and use its unmanned systems to greatly extend the area it can influence.

The focus of these ships would be their mission bay and unmanned systems, which could offer a great deal of flexibility. Ships would have a variety of mission packages, similar to the concept for the Type 26. Ideally the mission bay would be a copy of the Type 26's, with both classes able to embark tailored mission packages from a common pool of equipment. Like the other concepts 24 Sea Ceptor cells would provide a basic self-defence capability. Aviation facilities should be sufficient to embark a single Wildcat, or a number of smaller rotary-wing UAVs, with an aviation deck and hangar sized appropriately.

There you have it, some sketched concepts for the next generation of RN frigate. Hopefully this brief foray into the realm of fantasy fleets helps stimulate some thinking about alternatives to the simple resigned view that these ships must be a less capable Type 26. In order to get the most from this class the Royal Navy could opt to take a different approach, by learning the lessons of successful past designs (British or otherwise) or looking to the future of unmanned systems. The RN consistently stresses the importance of credible surface combatants, hopefully I've demonstrated that while "credibility" necessitates a complex baseline equipment fit there is also a great deal of flexibility in the way that future UK surface ships could be equipped to carry out their duties.

Post-script:
This article has come under scrutiny from some who dismiss it as a "fantasy fleet" piece. I fully accept that this is indeed the case, and that I went into writing this with the intention of stimulating thought and discussion about some possibilities outside the "normal" conception of a UK surface combatant. The ideas here were never intended to be serious proposals for future UK warship designs. I am, however, happy to see that there is a lively discussion on the UK's next generation frigate going on at the UK Defence Forum. As ever I'd like to thank you, dear reader, for taking the time to read what I've written.