Thursday, 10 December 2015

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.

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.

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