Some Thoughts on the Batch 2 River Class



Since the first information was published about the second batch of the River-class patrol ships, officially referred to as Offshore Patrol Vessels (OPVs), I have felt that they have been widely misunderstood. I believe they could be a much more significant development than is generally believed.

The origin of the R2s is, as is well known, the BAE Systems 90 m OPVs that have been sold to Brazil (three, originally built for Trinidad and Tobago) and Thailand (one, with a second now on order and perhaps more to come). I shall refer to this design as the BAES OPV. It is well known that the first three R2s will cost much more than the three BAES OPVs that ended up with Brazil (which is using them intensively, by the way, often on international missions).

The figure for the R2s has been given as £348-million, while the three BAES OPVs that Brazil bought cost £155-million.

Now, the first key point to note is that both the Ministry of Defence (MoD) and BAES have stated that the design of the R2s is “based on” that of the 90 m OPV. “Engineers at BAE Systems have modified the design to meet the requirements of the Royal Navy,” said BAES in a press release dated 8 June 2015. This means that the R2s are not the same design as the BAES OPVs. They may look the same externally, but internally they are going to be different.

The question is: how different?

Let us look at the list of changes again:-

  • Watertight integrity modifications (also described as improved watertight integrity)
  • Fire safety modifications
  • Enhanced firefighting facilities
  • Automatic emergency lights
  • Flight Deck Officer position
  • Domestic refrigeration modifications
  • Sewage treatment plant modifications
  • Ballast water modifications
  • Merlin helicopter operation (ie strengthening the flight deck to be able to land a Merlin helicopter on it)
  • Helicopter in-flight refuelling
  • Helicopter refuelling modifications
  • Changes to ship’s minimum operating temperature
  • Davit modifications
  • Force protection weapons modifications (replacing 2×25 mm with 2×7.62 mm Mk 44 Gatling guns)
  • Installation of WECDIS/WAIS (WECDIS stands for Warship Electronic Chart Display and Information System; WAIS might stand for Wide Area Information System. This seems to be an improved version of the system fitted to HMS Clyde.)
  • Install Combat Management System (CMS), and the new RN standard BAES “Shared Infrastructure” which will equip the RN’s entire surface fleet over the next nine/ten years (this integrates ship sensor, weapons and management systems using a common console system).
  • Military communications modifications
  • Magazine protection (if my memory serves me correctly, this involves the fitting of Kevlar armour)
  • Radio equipment room modifications
  • Change lighting and domestic power voltage from 115 v to 230 v
  • Codification of equipment
  • Provision of life saving equipment
  • Replace navigation radars (fit the Kelvin Hughes Sharpeye)
  • Install military GPS
  • Install flight deck landing grid
  • Fuel efficiency monitoring
  • Provide emergency communication equipment
  • Machinery space walkway

The Ministry of Defence and BAES also report that the R2s will have increased stowage space.

Finally, originally it was proposed that the exhaust system be modified, but reportedly that has been determined to be no longer required.

Before going further, this list bears examining in terms of what it tells us about the BAES OPV design, or more precisely, their reduced operational capabilities. Most notably, their reduced watertight integrity, basic fire fighting facilities and the lack of protection for the magazines. This emphasizes that standard OPVs, like the BAES 90 m, are not designed for combat. They are naval vessels, but definitely not warships. They can handle smugglers, pirates and small-scale terrorist groups, but nothing greater than that (including major terrorist movements). It’s not about armament, it’s about their inability to absorb battle damage.

Enthusiasts for upgunning OPVs tend to forget this.

A 76 mm gun system with an unprotected magazine could turn an OPV into a death trap if it got caught up in a real shoot out, even if the opponent had lighter calibre weapons. A 76 mm gun is useful for intimidating modern large, ocean-going fishing vessels that may be bent on poaching, and so is a valid option for, example, the Irish Naval Service (which has no corvettes, let alone frigates) but it carries the risk that politicians will see the OPV as more powerful than it really is and order deployments in areas where it should not go.

Generally, many online commentators have dismissed the modifications to the BAES OPV design to convert it into the R2 design as being secondary or not important enough to justify the greatly increased price tag.

I believe they are wrong.

First, let us consider the watertight integrity improvements. How do you improve watertight integrity? I would argue that this would require additional watertight bulkheads and/or the fitting of shock-proof water inlet and outlet valves, pumps and pipes. With watertight bulkheads, one wants them to have as few points of penetration (for cables, pipes, etc.) as possible, and these to be as high up on the bulkhead as possible. So fitting even one new such bulkhead would require a noticeable redesign of internal hull systems. Improving existing watertight bulkheads (by, for example, reducing, or changing the location, of the points of penetration) would also involve internal redesign. Shock-proof pumps, valves, etc., will be significantly more expensive than their non-shock counterparts. They may also take up more volume, again requiring internal redesign. And improving watertight integrity also probably has consequences for the air conditioning system.

Ballast water modifications would also, I suggest, involve a degree of internal redesign. It may be possible to fit the new sewage treatment system in straight swap for the existing system, provided it has the same dimensions and weight. If not — then some redesign would be needed. Fire safety modifications may also involve some internal redesign or the fitting of better, but more expensive, fire resistant materials, or both. Regarding magazine protection, Kevlar is not cheap and we do not know how much is needed.

I won’t go through everything: some new systems will indeed involve simple swaps for existing systems. However, the new, strengthened, flight deck will be heavier than the existing flight deck. You just can’t drop a heavier flight deck on the existing structure, I would argue. It would increase the stress on the hull. So I believe that the fitting of the new flight deck must involve a strengthening of the hull, either by having stronger hull frames or more hull frames, or a mixture of the two. That, too, would involve redesign. Also, while the fitting of the machinery space walkway may have been a simple affair, it might not have been: it might have involved some redesign of the machinery space. After all, if a machinery space walkway was not part of the original BAES OPV design requirement, would any provision have been made for it in the original design?

The Flight Deck Officer position had to be designed and integrated into the Ship’s superstructure in such a way as not to interfere with the crane, or other fittings and equipment, and integrated into the various ship systems, including power, communications and air conditioning. This might have been straightforward, but then again it might have involved some delicate redesign. Increased stowage space also suggests some internal redesign.

In addition, don’t forget, all these internal changes cannot be made in isolation. They have to be coordinated and made compatible with each other and with the rest of the ship and its systems. That involves design work. And, of course, the time of designers (naval architects) is expensive.

But why these changes? To me, improved watertight integrity, fire safety modifications, enhanced firefighting facilities, automatic emergency lights, magazine protection and the installation of a machinery space walkway (which will clearly give easier access to machinery at sea, allowing emergency repairs) suggest that the R2s, unlike the BAES OPVs, are designed to engage in battle and sustain damage. Or, in other words, they are real, if lightly armed, warships.

Also very suggestive in this regard is the unprecedented top speed of the R2s, in comparison to the RN’s previous OPVs — 24 knots. The RN’s original OPVs, the Island-class, could manage 16.5 kts. The larger Castle-class could reach 19.5 kts. The current R1s have a maximum speed of 20 kts and HMS Clyde, 21 kts. The R2 maximum speed is more than needed by a standard OPV and just, I would argue, inside the warship range.

And if the R2s are real warships, in terms of the hull structure and systems, then it makes enormous sense to use them to replace the current River-class Batch 1 (R1) vessels, which are standard OPVs, and of no use in conflict scenarios at all, and thus provide no flexibility in deployment. (And, if the R1s have no magazine protection, then it is hardly surprising that the RN restricts their main armament to a single 20 mm gun.) The R1s can be sold or transferred to small navies or coast guards for which a seagoing OPV would represent a major increase in patrol capability, such as a number of Caribbean or African countries. They might also make useful secondary-level patrol ships for navies like Uruguay’s or Bangladesh’s. They could even conceivably end up with the UK Border Force. While it might make sense to keep the one “R1.5” ship, the helicopter-deck fitted HMS Clyde, in service (in home waters) after the five R2s are all commissioned, it must not be forgotten that she is not fitted with the new “Shared Infrastructure” system and I doubt it would make sense to refit her with it, so she would probably have to be retired in a decade or so, anyway.

Now, of course, if the R2s are real warships, why are they so lightly armed? I would argue that their armament is perfectly adequate for their intended peacetime roles. The main armament is reported to be a single DS30M 30 mm cannon, a remotely-operated gyro-stabilised electricity-powered system. This has a reported maximum range (in a naval role such as this) of 5 100 m. This is greater that the range to the visual horizon at sea level, which is about 4.7 km. It has a rate of fire 100/200 rounds per minute and uses armour-piercing incendiary (API) and high explosive incendiary (HEI) ammunition. It can also use armour-piercing fin-stabilised discarding sabot tracer ammunition, although whether such rounds would be used in a naval context is unclear. I would argue that this weapon is capable of doing a lot of damage even to larger targets, and certainly to the kind of target an R2 would be most likely to meet in the real world.

The most severe likely threat an R2 would face in normal operation would be a swarming attack by terrorists in small boats. Now, to succeed, such attacks must be launched at short range, otherwise the attackers will be cut to pieces by the 30 mm gun: the boats employed in such attacks would be small and fragile and a single 30 mm hit, or even proximity detonation, would disable one. Such early losses would eviscerate an attack. Given the necessity of a short-range attack, the shorter range of the Mk 44 Gatling guns (in comparison to the 25 mm cannons carried in the BAES OPVs now operated by the Brazilian Navy) is, in this scenario, quite irrelevant but their higher rate of fire is very relevant. Also, given the fragility of the attacking boats, the calibre of 7.62 mm would be perfectly adequate. (The have been pictures of pirate and rebel skiffs operating in the Niger River Delta armed with 12.7 mm or even 14.5 mm heavy machine guns, but these are not to be taken seriously; the moment they hit the sea, even on a calm day, their gunnery would be wildly inaccurate and utterly useless, except to intimidate unarmed and defenceless merchantmen.)

Moreover, it is a pretty safe bet that the RN has not only exercised swarm attacks, but that Ministry of Defence scientists, in what used to be (and maybe still is) called Operational Research (OR), have simulated and modeled them. Such research could be carried out by the MoD’s Defence Science and Technology Laboratory, or DSTL (which, according to its 2014-2015 Annual Report, has 3 839 staff, 90% of them permanent, so it is a substantial, heavyweight, research and development organisation) or be contracted out by DSTL to Qinetiq.

OR has a fantastic record of success, because it is applied science, and many of its findings in the past (eg, Second World War) have been in complete contradiction to what was then regarded as common sense, but proven to be true when put into practice. OR was and is also highly secret, so the only results we see are in, for example, apparently strange weapons choices. I would suggest that many of the RN’s seemingly odd weapons and equipment choices for its ships are based on OR. If the OR boffins (to use a good, old-fashioned, term) gave their approval to the Mk 44 Gatling, then it is the right choice. These comments also apply, of course, to the R2s main armament.

The other probable reason for the light R2 armament in peacetime is what political scientists call bureaucratic politics — interdepartmental disputes (over policy, budget and so on). In this case, a more heavily armed R2 could lead the Treasury to argue that it was a corvette (which, at 24 kts, it is not) and could serve as a cheaper substitute for more frigates (specifically, for the planned General Purpose Frigate).

But what about the R2s during a sustained, State-on-State, conflict? What could they do in such a scenario? The key here is the flexibility of the design. The first key point is the fitting of the Shared Infrastructure common control system. This, of course, makes great sense in terms of training and operating experience for the crews. Although the fit is likely to be relatively basic, I would suggest it would still make it easy to upgrade the weapons and sensor systems on an R2, if and when required, because the information technology backbone would already be in place.

The ships will be equipped with the Terma Scanter 4100 radar for surveillance. According to Terma, the Scanter 4100 can provide 2D air surveillance to a range of 90 nm and 35 000 ft in altitude. It can track up to 100 air targets (subsonic and supersonic). In the surface role, its range is out to the radar horizon (ie, depends on high up the antenna is mounted) and can track up to 500 targets. The company affirms in a brochure that the “accurate tracker allows for transmission of target data to the Command Management System or Fire Control System for target designation”. This suggest that the R2s can be up-armed without needing any new radar fit.

Furthermore, the BAES OPV can be fitted with up to six 20 ft ISO containers. There is no indication that this capability has been removed from the R2s. This means that the ships will be able to be fitted with just about any system or equipment that can be containerised or palletised. One can easily imagine the ships being fitted with containerised/palletised mine hunting systems, or mine laying systems (for defensive mine laying, probably in support of allies), or containerised workshops and spares stores to act as command and support ships for minehunters or patrol boats, or a containerised/palletised system carrying unmanned surface vessels and extra rigid hull inflatable boats allowing the ships to serve as forward force protection base ships. One could even image them being fitted with palletised Sea Ceptor missiles (would should be relatively easy to do) — assuming each pallet carried six Sea Ceptors (as would be carried by each vehicle in the land-based version of the missile), an R2 could carry anything from six (one pallet) to 36 (six pallets) missiles, making it a very useful local area air defence escort for amphibious ships and auxiliaries. Likewise, one can easily envisage the ships embarking containerised unmanned air vehicle (UAV) systems. Not very long ago, it was officially stated that it was not envisaged that these ships would carry UAVs, but a lot has happened since then and that position will likely have changed by the time they enter service. (The most likely reason why the R2s might not deploy containerised UAV systems is the apparent success of current experiments with 3D printed tactical UAVs being undertaken by the RN; I would not be surprised if the R2s entered service with 3D printers installed as standard fit.) The fact that none of these proposed containerised/palletised systems currently exists is irrelevant; it is highly likely that, in an emergency, many of them could be developed, tested and deployed in a matter of weeks. Of course, if most or all the container spaces are occupied, the flight deck is likely to be covered and unusable; but the ships will still be able to refuel helicopters using their helicopter in-flight refuelling systems.

Then there is the flexibility made possible by the absence of a helicopter hangar. Yes, you read that right. Flexibility has many dimensions. Not having a helicopter hangar cuts flexibility along one axis but increases it along another. For a start, the R2s would not be able to carry up to six containers if they had a hangar!

Before going any further, it is necessary to highlight that the fact that one of the modifications to the BAES OPV design to create the R2s is the addition of a flight deck officer position. In addition, a press release by Kelvin Hughes states that the R2s will each be fitted with two types of SharpEye radar — the E/F band navigation and collision avoidance radar and the I-band Doppler helicopter control and navigation radar. These two facts clearly show that the RN fully intends to carry out extensive helicopter operations with the R2s.

Do not forget that the RN has decades of experience in operating ships with flight decks but no hangars. During the Second World War, the RN operated a number of Merchant Aircraft Carriers (merchant ships fitted with flight decks but which continued to carry cargo — grain or oil, which were loaded and unloaded using hoses) that had no hangars: their air groups of three to five Swordfish were lashed down and maintained on the flight deck when not flying. These were used for convoy escort in the North Atlantic. Then, in the mid-1960s, the converted tank landing ship HMS Lofoten, serving as the RN’s first helicopter support ship, successfully operated Wessex anti-submarine warfare (ASW) helicopters on a sustained basis over several days during RN and NATO exercises in the North Sea and (I think) Norwegian waters, despite having no hangar. (My father was one of the Fleet Air Arm maintainers embarked during these exercises, which served to test the Wessex in the ASW role.) Another example is provided by HMS Fearless, which, during the Falklands War in 1982 embarked and operated three Sea King assault and three Scout helicopters despite having no hangar. (Sister ship HMS Intrepid likewise embarked and operated Sea Kings.)

So, contrary to opinions often found on the web, ships with flight decks but no hangars can operate helicopters, not just refuel them. Of course, the length of time they can do this depends on the size of the ship and the weather. And the fact that the R2s are also to be fitted with flight deck landing grids shows that the RN is determined to push the weather/sea condition limits on helicopters operations with the R2s.
Of course, the period that smaller ships without hangars can operate helicopters is likely to be measured in days, whereas a ship with a hangar can operate a helicopter for months. But it does mean that the helicopter operating capabilities of the R2s are much greater than they are usually given credit for.

The other source of flexibility for the R2s resulting from their lack of a hangar is that fact that this allows them to have a larger flight deck, capable of taking the Merlin. As the RN is standardizing on the Lynx/Wildcat and the Merlin, and these will carry out all helicopter roles and missions within the Fleet Air Arm, this means that the R2s will be able to support all these roles and missions: anti-surface vessel warfare, ASW, airborne early warning, assault, and so on. I was going to suggest a number of possible scenarios, but that would only make this piece even longer than it already is! Suffice to say that the R2s will be able to act as floating, moving, forward operating bases for helicopters detached from larger units (frigates, destroyers, aircraft carriers) or from shore bases, for one, two or a few days, depending on the mission, type of helicopter and weather conditions. I will give one scenario: a Type 45 could detach a Wildcat to an R2 operating in coastal and/or inshore waters, for anti-ship reconnaissance and attack missions. The much smaller R2 would have greater freedom of manoeuvre in such waters & if, the worst came to the worst, would be expendable. Also, in many parts of the world, such waters are sheltered and an R2 might very well be able to operate a Wildcat for a week or more (it would be perfectly capable of embarking the necessary maintainers, spares and tools for routine support of the aircraft). In other situations, an R2 might be able to embark and operate an ASW or AEW Merlin for a couple of days.

To sum up, first, I believe that the modifications to the BAES OPV design to create the R2 are — or at least some of them are — extensive and important and justify the significantly increased price. (Of course, I might be wrong, but I do not think I am.) Second, these changes convert the ships from standard OPVs to real, if lightly armed, warships, with significant flexibility designed into them. Indeed, I cannot help wonder if — although the RN will never so describe them, for reasons of bureaucratic politics — they are really sloops. But not, I hasten to add, the much talked about “Black Swan” concept. The Second World War “Black Swans” were, for their size, heavily armed (main armament: 6×4″ dual purpose guns) and specialised (anti-aircraft) escorts. Clearly, the R2s bear no resemblance to such ships. No, the sloops I am thinking about are the First World War Flower-class (not to be confused with the Second World War Flower-class corvettes). These were highly successful, very seaworthy, multipurpose vessels, but were never heavily armed. The first 24 examples had a main armament of just two 12 pounder guns (and a secondary, anti-aircraft armament of two quick-firing 3 pounders). Later examples had a main armament of two 4″ or even two 4.7″ guns (plus the 3 pounders) — still on the light side, by the standards of the day.

Of course, we won’t know for certain until the ships are built, commissioned and in service.

But, while the RN may not have originally desired the R2s, they do seem to have made a virtue out of a necessity.


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