Sunday, 1 September 2013

August 2013 Notes: Can USVs and UUVs be the future of Task Group operational security?

Reason for writing:

The issues of hull numbers, but more importantly Eddie B had a great idea and we decided to work together to produce something.

Key Words/Phrases:

·         VSTOL: Vertical/Short Take Off and Landing, the cheapest system of carrier flight deck, but requires the most expensive aircraft… the Royal Navy (RN) was the first navy to employ this to provide its fixed wing airpower, but that was out of necessity when the first Queen Elizabeth class was cancelled (CVA-01 was due to have been called after the Queen) and all it managed to get built were the ‘Through-Deck Cruisers’ of the Invincible class.

·         F-35 Lightning II (Joint Strike Fighter): produced in multiple variants, B for VSTOL and C for CATOBAR, this is the new stealth jet strike/fighter (what used to be called a Fighter Bomber…i.e. could fight its way to the target, drop its bombs and fight its way back) coming into service with the RN for the Fleet Air Arm to fly of the carriers.

·         Eurofighter Typhoon: Principle aircraft belonging to the Royal Air Force at the moment, a Cold War inspired Dog-Fighter that was used in conjunction with Tornadoes over Libya to do some limited bombing… although it was the much more venerable Tornadoes which had to aim the weapons.

·         NATO: North Atlantic Treaty Organisation – Britain’s principle strategic alliance,

·         Type 26 Global Combat Ship: no not a British version of the USN’s Littoral Combat Ship, but a Frigate successor to the Type 22 class

·         Type 45 Daring class, the RN’s proposed fleet of 12 Area Air Defence (AAD)/General Purpose Destroyers, of which only 6 were built and in their in service condition (only 4 have harpoon, no strategic length VLS cells were fitted limiting them to SAMs only) they are AAD vessels


Based on current projections the RN will have just 19 surface combatants, and 7 attack submarines; these vessels will be required to provide escorts for a carrier battle group, an amphibious task group, guard ships, strategic deterrent security and intelligence missions – all whilst possibly as many as 7 surface ships and 3 attack submarines will be undergoing maintenance/refit. There is of course no question that these ships are more powerful than their predecessors, but they can only be in one place at a time – whether on the globe or in relation to a Task Group. A practical example of this would be Cougar 11, 12 & 13; major RN deployment exercises that have included major capital ships but have only had two Type 23 frigates for their escort…no Type 45 destroyer for air defence (something which considering the cuts of the Harriers which would have provided Area Air Defence would be really sensible) and no submarine since Cougar 11. These are major exercises, which are very important and highly visible statements of British expeditionary capability, upon which rests the Government’s ability to deter conflicts; and yet those same deployments are critically weak if properly examined. Therefore the questions comes as to how to solve this problem, one option put forward would be to change the RN to destroyer/corvette navy[1] & SSKs[2] to complement the SSNs; the other, and it’s not an either/or option, they are complementary - would be to use larger USVs and UUVs to support Air Defence, Anti-Surface and Anti-submarine missions. Like UAV’s, USVs offer sever advantages in comparison to manned vessels; although of course they are limited by not being able to board other ships (counter piracy), host diplomatic events (naval diplomacy/conventional deterrence), exercise local command & control (it requires hosting personnel) and self-maintain (requires a crew) – but there are advantages.

Warship design has always represent a compromise between a wide number of factors, principally hull shape for seaworthiness, and the spaces given over to such things as crew space, facilities and provisions; engines, fuel and steering; and finally weapon systems and munitions. In particular crew space is complicated by the needs to support the crew for potentially very long periods at sea, and that the entire crew cannot perform 24/7, but needs to operate in shifts or ‘watches’. Crew space is minimised in boats that operate close to base, and in extreme cases, such vessels may not carry provisions more sophisticated than drinking water and no bunks, or just one crew. The advantages of an unmanned vessel must include even further reduction (to zero) of crew space and facilities.

The picture below shows a sketch of a large USV. Diesel Electric propulsion has been chosen for reasons of fuel economy, design spacing/weight distribution and the fact that with sufficiently large batteries the vessel would be capable of going silent; plus solar panels could be fitted should it be found to increase range/reduce fuel consumption sufficiently. The engine mass and fuel tanks would be below the water line, as would vulnerable computer systems. Exhausts would be sprayed with sea water to minimise any heat signature. In the sketch, the upper works have the wedge shapes and surface treatments that would give such a vehicle stealth characteristics, and moreover, the boat could be given the self-righting behaviour of an RNLI lifeboat by appropriate disposition of buoyancy and weight. As for dimensions, this is assumed to be the size of a Landing Craft Utility; i.e. about 25-30m in length, 7-8m in beam and a displacement of 230-250tons[3].

 Figure 1: a rough sketch of the USV, source: Eddie

Whilst for self-righting a mono hull design would be better (with possibly a Polyurethane inflatable collar like that fitted to a Rigid-Hulled-Inflatable-Boat (RHIB) to improve buoyancy and sea keeping in rough waters[4]); although a catamaran would offer better stability and more space for weapons plus a shallower water profile. For steerage and propulsion there are more options with the larger sized USVs compared to the smaller ones; it could be done by either a conventional rudder or through a ‘podded’ system[5], and indeed of such refinements as deployable deep keels and stabilising “wings” could be fitted to improve handling.

Apart from a wake, such a vehicle could be made virtually undetectable from a satellite or high altitude reconnaissance system, especially in comparison to a destroyer size ship. With a certain amount of ingenuity, the already stealthy shape and composition of the upper-works could be helped by pumping seawater over them, or indeed, by changing their shape as the vehicle is not so constrained by aerodynamics as one that flies. For Britain with experience gained producing the Hunt class minesweepers[6], there is also the option of using Glass Reinforced Plastic; which would make them even less visible to electronic detection methods, and give them an advantage against magnetic mine’s in littoral operations.

As illustrated, the USV is armed with a concealed Close-In-Weapon-System (CIWS) and a Vertical-Launch-Systems (VLS), also concealed. The shape of the upper-works makes it difficult to board the vessel, and indeed, it could protect itself with high pressure water cannons. While concealed weaponry improves stealth characteristics, such a vessel would need to “uncloak” before opening fire; but then so does a B2 Spirit, F-22 Raptor, F-35 lighting and J-20 when they open their bomb bay doors, so it’s a calculated necessary risk.

Should an effective laser CIWS be developed, then this could prove the ideal protection for it, as it is the Phalanx system would be too tall, whereas the Oerlikon Millennium 35 mm Naval Revolver Gun System[7] which is a capable system would fit more within the profile of the design[8]. Missiles would be limited, a strategic length VLS would most likely be out of the question, but a 16 cell Sylver A43 VLS could be housed, capable of taking aboard 64 CAMM/Sea Ceptor, 16 Aster 15 or a combination thereof. In theory a well-designed ship might even have side ports for the launching of helicopter torpedoes like the Sting ray. Now whilst primarily it would be designed to give these weapons a target solution based upon second hand data from the mother ship or nearby warships, fitting of at least a passive sonar system would be sensible. Furthermore if a radar was fitted on top of a hydraulically raised mast so it could be positioned at a suitable height should the situation require (either lack of options or a desire to confuse the enemy as to the position of the manned escorts); similar masts could be used for the communications array and an ECM system. This would represent a very useful system.

Take for example a carrier battle group. Conventional thinking would be to deploy an aircraft carrier surrounded by a group of variously configured manned vessels that provide Area Air Defence and ASW capabilities some distance from the capital ship & auxiliaries. However, there are always two layers an inner as well as an outer layer. The inner layer is there to provide ‘point’ coverage for the high value units, and traditionally under armed auxiliaries. Now could not this role be provided by USVs discussed? The answer is almost certainly yes, given today’s mastery of computers, weaponry and most importantly digital communications.

Provided that USVs do not operate over the horizon from a mother ship it is in line of sight at all times, and tight-beam microwave radio links operating in burst mode provide inter-vessel communications or alternatively a laser based communication. Should over the horizon communication be required then a UAV could be used as relay[9]. While satellite communication would be possible (and wise precautionary back up[10]), it could be operationally problematic as it would be tempting for command to be taken away from local commanders by commanders at ‘home’ – leaving the local commanders unsure of what their systems would do.  Such communication could contain multibit encryption that would defy enemy attempts to spoof signals or read them even if they did manage to find them (they great advantage of laser line of sight communications is that they are virtually undectable[11]); important in today’s world where enemies are getting increasingly technologically capable, for example the alleged spoofing of GPS signals by Iranians that allowed them to ‘capture’ an American UAV.

One could envisage a Carrier Battle Group (CBG) operating with perhaps 6  Large USVs operating at a distance of 8-10 nautical miles from the mother ship, carrier and the rest of the vessels composing thee group core, in a broadly hexagonal array.  These would then provide an inner screen protecting an area of over 300nm2, through which anything that tries to get through will be intercepted. Allowing the manned escorts, the Destroyers and Frigates, to concentrate on providing the up threat AAD & ASW pickets; the later at about 30nautical miles and the former at about 100 nautical miles (or 77s at Mach 7[12]) from the group core. Should the task group move inshore or be operating at a slower speed, then smaller USVs could be deployed to provide a more comprehensive web; an Amphibious Task Group (ATG) which would proceed at a slower pace anyway (~20kts) would be more likely to deploy these than the CBG (25-30+kts), especially during the phases of operations taking place within the littorals.

When a navy such as the Royal Navy builds groups of as little as 6 ships[13] then each is for all intents and purposes a hand-built example. With varying levels of difference as they come into operation one by one, and the manufacturers learn from experience: and possibly are forced to make economies or changes due to design faults in later ships of the class. Therefore Britain can never get the economies of mass production[14], and rarely gets the opportunity to replace a whole class of such ships on a one to one basis due to changes in the project emphasis or costs during procurement & build. The much smaller USVs provide both, as orders could be given for the construction of dozens at the same time; and most importantly due to their size could be constructed by a far larger number of yards.

The reality is though that with no crew aboard to maintain them, they will need some sort of mother ship to be deployed alongside them when operating away from the home bases. This vessel would provide with servicing, refuelling, maintenance and repair, and also carriage to areas where they would be deployed. A suitably modified Bay class[15], with hangar space for the Lynx & UAVs as well as the addition of a crane in the well deck, alongside the retention of the one on deck would be a very suitable design to follow; as there are plenty of spaces that can be used for personnel and stores, as well as to put the Command & Control facilities. The Lynx would be used to support maintenance teams, should a USV get into trouble, whether one that belongs to the mother ship or escorts, it could fly them out and deposit them aboard the ship. The UAVs it would carry to provide over watch for the USVs, allowing them to operate in unmanned aerial/surface ‘tag teams’; more importantly they would facilitate over the horizon communications and perhaps even AEW for the group.

Figure 2: RFA Cardigan Bay, undergoing maintenance in Falmouth. Source: Alexander (Author)

UUVs were mentioned in the title but have not really been discussed to the same level since, and there is a reason. Whilst they are developing, have been in service for decades[16] and in future they could well take on the role of task group protection, so must be born in mind, but there are problems. Therefore whereas the USV could be ordered tomorrow, and definitely in operation within 18 months; as of yet communications with underwater craft have not reached the point to facilitate the constant feedback necessary to make a UUV capable in the ASW tasking. As has been said though they are in use, although not called UUVs, they are called AUVs or Autonomous Undersea Vehicles. The difference is because with the lack of two way communication they have to be virtually independent of instruction while doing much of their work. These systems are used for mine warfare, for monitoring areas for activity whether geological or biological and also for Hydrographic Surveys. They are excellent, but their very autonomy which makes them so useful for these roles, and is necessitated by the medium in which the work is what makes them currently unable to be used for task group protection – what happens if a permission to fire signal is sent and it gets mucked up by the water and it doesn’t fire, or worse fires at its own side? The USN predicted that they would solve the communication problems within 20 years in 2007, and it hasn’t happened – at least not on a level that has produced numerous support USVs; we cannot be 100% sure about what’s capable in the experimental units or special operations teams where cost is less of a restrictive factor. Beneficially though, the experience with AUVs will enable USVs to be made that much better, their software, the operational experience gained in their use and their sensors will all be of great value in making the USVs as strong, as self-reliant and as autonomous as possible whilst still remaining the level of communication that enables them to be a fully active protector of their Task Group.

Key Points:

·         Force Outline

o   6 x Bay Class UV Mother Ships for USVs & Rotary UAVs (3 Mother Ships will be Regular, 3 will be Reserve[17])

o   76 x USV Large = 36 (6 USV large for each mother ship) + 16 for UK Patrol + 8 for Falklands Patrol + 8 for Gibraltar Patrol + 8 for reserve/deep maintenance

o   74 x USV Small = 19 (1 each for the Destroyers & Frigates) + 24 (2 each for Amphibs & Mother Ships) + 8 for UK Patrol + 4 for Falklands Patrol + 4 for Gibraltar Patrol + 11 for reserve/deep maintenance

o   6 x Lynx Wildcat (1 for each UV Mother Ship)

o   36 x MQ-8 Fire Scout (6 for each UV Mother Ship)[18]

·         Therefore a UV Mother Ship group would be (per ship):

o   1 x Lynx Wildcat for supporting operations, mainly dropping off & picking up deployed maintenance teams when they need to visit the USVs…a dedicated aircraft is required because it will be needed to be maintained at alert level due to the importance of keeping the systems going.

o   6 x MQ-8 Fire Scout

o   6 X USV Large

o   2 x USV Small

·         A Task Group with a carrier and four escorts in addition to the UV Mother Ship would be able to count on 6 large and 6 small USVs to supplement their escorts. Furthermore in times of war, with up to 6 vessels available then the government could choose to reinforce guarded points, Task Groups or replenishment groups.

Figure 3: A Rafael Protector Patrol USV[19]

Points of Interest:

·         USVs once in service could well produce technology that would ‘spin off’ into manned vessels, reducing the level of crew required by those ships (although of course some extra crew would be required to control the USVs, UAVs and someday UUVs) – perhaps reducing manning or alternatively providing more space for Royal Marines or Mission Specialists.

·         Technology will get better, but in a counter argument until machines gain the ability to learn, improvise and make it up as they go along when necessary the naval personnel are always going to be a resource that can be overvalued nor under appreciated.

·         Officers are not the only solution; recently a lot of moves have been made to make control/piloting of unmanned systems officer controlled and an officer specialisation – whilst to an extent it should be, the questions should be asked do we need personnel with such a career trajectory to do the role? There are arguments for and against an all officer flying force, let alone unmanned systems; surely therefore whilst a ship might have a UAV officer and USV officer (probably senior Lt’s reporting to the Warfare Officer), it would also have a Warrant Officers and a Couple of Chief Petty officers assigned to each section who would do the actually ‘controlling’ with some leading seamen & seamen to do the maintaining. Such a system would allow for personnel to have a career progression, and also provide plenty of officers with familiarity with the systems. The ‘command’ would of course be held by the captain, but would also most likely be exercised by the offer in charge of the branch the assets were assigned to, i.e. if a UAV was being operated in ASW mode it would work under the charge of the Anti-Submarine Warfare officer, if it was providing AEW then it might be under the charge of the Warfare or Air Warfare officer – a USV would be similarly assigned.


As was said at the beginning the Royal Navy no longer has the ships it once had, and it needs them, it’s escorts are stretched doing so many missions for the government it’s a surprise there are not more accidents & break downs. It’s testimony to the training, the talent and the commitment of the RN’s engineers that there aren’t. The fact is though that none of that, no matter how great can give the RN the greater number of ships it needs. Leaving aside the requirements of naval diplomacy and other similar missions which require personnel, the USVs are very sensible option; they would not be expensive to produce as they would leverage mostly off-the-shelf technologies, or technologies which are almost at that point. The combined tonnage of the large USVs (at 76x 250tons = 19,000tons) is less than 40% of the combined tonnage of the 6 Type 45 Destroyers and less than 28% of the combined tonnage of the proposed 13 Type 26 frigates; for this relatively small amount therefore the RN would gain massively in terms of force protection and operational security. It would be able to let its manned escorts vigorously defend the task groups knowing that there was a strong defence line behind them: giving commanders the freedom to act more aggressively and take more risks…allowing them more opportunity therefore to set the pace of confrontation and as consequence being enabled to take more control of it.

Further Reading: - definitely worth a read


[3] A smaller vessel would also be good for deployment with individual escorts, this would be about 24tons (Landing Craft Vehicle Personnel (LCVP) sized), a length of 15-16m, a beam of 4-5m; it would be fitted with something like the 30mm DS30M Mark 2 Automated Small Calibre Gun, and possibly some 4 silos of Common Air Modular Missile/Sea Ceptor, alternatively it might be able to fit an 81mm mortar or anti-tank missile launcher so as to be able to provide support for landing forces.
[5] With the advantages of course that such a system could be easily slotted in & out to save on maintenance time, plus such a system has the advantage of only electric cables running through the ship, rather than propeller shafts.
[8] A gun-based CIWS needs of course to point towards its target, and this is facilitated by it both being raised up when activated and the ability of a USV to turn rapidly to make sure it’s weapons are orientated on the threat. The range of a CIWS means that it could fire at a sea-skimming missile both as it approaches the screen and also when it has penetrated the screen as the CIWS can fire towards the mother ship without a chance of hitting it.
[9] UAV’s for communication has been discussed in another set of notes August/September 2013.
[10] This would be especially useful when it comes to monitoring maintenance issues on the larger USVs, whilst the local mother ship would be responsible for replenishing, conducting maintenance, re-arming them; the fact is that a pool of experienced engineers at home monitoring the systems would be a useful resource pool, and would be able to keep track of issues across all the vessels in service.
[12] The speed of the Brahmos II missile, which is shaping up to be the most dangerous possible threat, (27/08/2013)
[13] As was the case with the Type 45 Daring class destroyers
[18] This number would be in addition to any bought as suggested in the notes published this month in Notes on AEW and UAVs & Cruise Missiles (August/September 2013)

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