First published: 19th May 2011 | Dr. Alexander Clarke
The recent Libyan crisis has highlighted the potency of modern cruise missiles, whilst of course not being the first time they have been used. However, their key role in not just attacking targets but in neutralisation of enemy air defences is something which has grown with experience and is something which they are proving better and better at. There is though a problem. To be utilised properly they require a level of saturation. Whilst 112 Tomahawks were enough for Libya, to deal with problems in nations with more capable/more aggressive air defences, more are needed. This is a guiding light for this work. There are also other problems which come with these weapons. Cells taken up by Tomahawks cannot accommodate anything else, so a Tomahawk might be one less air defence missile. Now even in the Arleigh Burkeclass which does carry them and which has 96 MK 41 Vertical Launching System (VLS) cells. There is a limit to the number it can take before other areas of capability suffer. The Type 45 Daring class cannot even carry them due to the decision to fit them for, but not with, the MK 41. Instead the MOD selected the A50 Sylver VLS, which is too short to even take Storm Shadow, a shorter range cruise missile. The other problem is that quite a big ship is needed for these systems to work. Whilst in theory a distributed network of ships works very well, small ships are ships which are difficult to evolve…i.e. find the space to upgrade and modify them without overloading or ruining their lines, and if the network is distributed and communications go down the fleet would be rendered useless. Whereas ships with significant amount of inbuilt redundancy and self-sufficiency can still be capable of providing a useful service. There is of course also the expense, fitting MK41 VLS cells in every ship and auxiliary of the fleet would be brilliant and would disperse the capability, but it would also be expensive, require command and control systems to be fitted in every ship and would probably, like the idea of the fighters borne on cruisers and battleships prior to the 2nd World War, prove exceedingly difficult to integrate into the whole package almost certainly leading to problems.
Furthermore, Britain is facing a problem in the coming years. It is reducing from 3 aircraft carriers to 2, and whilst the Queen Elizabeth’s are certainly bigger, more capable, and more adaptable platforms than those vessels which they replace; and whilst British Forces may well be acting in concert with allies, the fact remains that even if they are, should there be just one carrier available then our forces might not have enough strike potential for the initial operations.
Furthermore, it will most likely be that the RN will not have enough escorts to provide the full level of support suitable for an amphibious operation of the type which may have to be conducted independently even if it is part of a coalition or allied operation. By this it is meant a reinforcement of Norway under the auspices of NATO, a reinforcement of Singapore, or any of the countless possible conflicts which may arise in the next 40 years, or two fleet cycles.
Above all these tactical considerations there is the strategic argument, deterrence. Being able to prevent wars from starting is the ultimate goal of any government, and the ultimate purpose to which all navies are best utilised. Whether the government subscribes to the view of being “A Medium Power with Global Interests”, “a Regional Power affected by the actions of the world through the interconnection of globalisation” or are following Lord Palmerston’s views about “Britain doing what is best for Britain”. In all these scenarios Britain needs a capable navy to ensure the independence of its action.
An arsenal ship will be explained further on, and is explained in far greater detail in reports. However, it is important to first discuss why this work is not recommending SSGNs or the building of more Carriers to cover this role.
SSGNs or ‘Submersible, Ship, Guided, Nuclear’ – a submarine dedicated to the carrying of cruise missiles
An SSGN does have benefits which attract nations to it. It is able to hide, can be deployed without the opposite nation knowing and without the security of covering Combat Air Patrol ‘CAP’ (which may be needed in certain operational circumstances). However, in comparison to the Arsenal Ship it is more expensive, far more difficult to resupply and rearm, will put a strain on British submarine building capacity which in the author’s personal view should be focused on SSNs, SSKs and the Strategic Deterrent. Furthermore, whilst the ‘invisibility’ of the Strategic Deterrent is a benefit for its capability and deterrence factor, the reverse is true for an SSGN as the government has to either tell the opposition it is there (which undermines the point of its ability to hide) or they will not realise it is there(which would mean it would have no effect). Finally there is the flexibility issue, as many authors have expanded upon it is quite possible for an Arsenal ship to deploy more than just land attack weapon systems, thereby allowing such a vessel to provide defensive as well as offensive support to any operation and, perhaps, to deploy weapons other than just missiles. It might act as a platform for helicopters, perhaps even a limited transport capacity, all of which an SSGN cannot do. Finally, there is the issue of expense, whilst the Russians built specific classes in the Cold War, even the Americans have gone down the route of converting SSBNs for the role, something which Britain does not have the luxury of doing as 4 such vessels are required for maintaining the guaranteed deterrent.
The Queen Elizabeth class in Catapult Assisted Take Off & Barrier Assisted Recovery ‘CATOBAR’ form will be excellent ships, but it is unlikely that money will be contemplated to build a third (no matter how good the strategic & operational arguments for it may be), and even with UCAVs embarked they are not arsenal ships – this is not the same as not useful, this just means they are different and should be respected as such. They will be able to provide land forces with on call air support, they will provide fleets with CAP to secure an outer shield against air defence, and they will be the flagships of the fleet as well as the central core of Britain’s maritime strength. Arsenal ships make use of expendable air power, and whilst UCAVs are cheaper than manned aircraft (and don’t cost lives), they are not as cheap as cruise missiles, and they have other uses which means expendability is not a primary asset. With a Queen Elizabeth to provide CAP an Arsenal ship can operate further inshore, they will therefore extend the Arsenal ship’s range by allowing it to close with the enemy – in other words the two will complement each other. The Arsenal ship increasing the fire power potential of the Carrier Battle Group massively whilst the carrier enables the Arsenal Ship to make best use of its weapon. However, it is important to note that a third carrier would provide enough operational capability to maintain 1 in operation and 1 available, and is therefore something which should be seriously considered, or rather re-considered in the light of recent events. An arsenal ship though would be cheaper, and could still be justified even should a third carrier be procured as it is a very good measure to provide a crucial future operational capability for dealing with opposition air defences.
Arsenal ships are not a new concept, the idea of loading a vessel with a small crew and large rocket based fire power has been around since before the time of Nelson, and was used to great effect in World War Two in the form of Landing Craft (Rocket); what is different is the size, scope and capability of the vessel which will embody the concept as it now exists.
Basically it is a vessel with a large number of VLS systems capable of providing massive levels of bombardment through the use of Tactical Low Altitude Missiles (TLAMs) or defensive fire with Surface to Air Missiles (SAMs). By containerising these VLS a nation would enable such a vessel to be restocked at sea, using either helicopters or perhaps a specialist auxiliary vessel. This also offers great flexibility, as to change a vessel from land attack to air defence, or to modify its standard load in anyway would just be a matter of disconnecting, replacing and then connecting in the new containers.
Strategically, whilst not as flexible a platform in the sense of a carrier, its deployment will carry tremendous weight and more often it may well become the centre piece of a force deployed for limited objectives or as the firepower for a littoral operation. Furthermore as a giant floating battery, with certain inclusions it could also be used to provide Ballistic Missile Defence (BMD) for the UK and deployed task groups, or provide a blanket air defence for those operations which should require it.
With the capability of a flexi-deck these vessels would be an enhancement to any amphibious operation through their ability to transport heavy equipment – however, disembarking such equipment through a side door will be possible, but not easy, and so it may be that they actually will focus on carrying equipment which can be transferred by their onboard rotary wing air group.
In the current circumstances a custom build, like that considered by the USN, is out of the question, but in the case of the RN this is a benefit as it will mean that costs will no doubt be reduced, the size of vessel to be procured and therefore its capability will be increased. As can be seen by the diagram to the left, even 20 year old 4th generation vessels can fit (16×10) 160 containers on one level inside its hull. This means there would be plenty of space for a flexi deck for the transport of equipment and personal, command & control facilities as well as self defence weapons, and of course a hangar facility for the maintenance of a number of helicopters. It would to be though a 4th generation vessel or 3000-5000 TEU vessel, a 1st generation or 1000-2000 TEU vessel (as shown on next page). Although it is (7×6) 42 containers per level would consequently produce a less powerful vessel and there would, of course, also be less space as a result.
Recommendation: on ground of cost/capability/modernity a vessel with the capability of around (12×10) 120 containers per level and of the 3rd/4th generation would be best.
* It should also be noted that the space within these vessels is perfect for the fitting of longtitudal bulkheads and subdivision which should provide them with adequate resilience if damaged. Furthermore the containers (see further on) if armoured/strengthened above the level needed for just supporting the missile launches would provide, with the natural compartmentalisation they by their very nature will create, a great deal of protection against the kind of weapons that do a ‘pop-up’ kill manoeuvre.
Most of the ships have a crew of between 20 and 40 personnel, and even with the requirements of manning weapons, providing sufficient automation and redundancy is built into the system then crew numbers would probably not exceed 60 although, this would not include personnel embarked for the purposes of operating the air group or as part of a transport operation.
Recommendation: keep as much merchant manning as possible to lower operating costs and crew requirements – as this will have other benefits which will be considered later
Propulsion would ultimately depend upon the money allocated, but if the government wished to spend as little as possible then the vessels procured might well be left diesel, as most container ships are built, however the more powerful and fuel efficient gas electric drive could be installed, or if the government is really interested in getting a lot out of these vessels nuclear power generation could be installed. Really the method of generating power is something to be considered along with the cost, the method of employing it though is not so questionable, pod propulsion would offer the best capability for the ship in terms of economy, stability, station keeping and utility.
Recommendation: Gas Generated Pod Propulsion
If containerisation is based on the MK41 VLS system being inserted into a standard (High Cube) TEU container (6.1m x 2.4m x 2.9m), as can be seen from below this would not be enough to fit in the height of Mk 41 VLS, so the ‘containers’ would need to be specialised, to a little over double the height of a High Cube, to something in the region of 6.5m. This actually makes it easier from a naval perspective, as stacking the containers one above the other is not something that the Arsenal Ship will be called upon to do, and within the auxiliaries this can be done on lines which whilst not being ‘commercial’ are financially and safety sound. With the height sorted the space of 6m x 1.8m (created by including suitable padding for cells 0.6mx0.6m and also space for the Command & Control interface system) provides for 30 full production slots; so it would be capable of taking 30 Tomahawks. The proposal of 120 containers would result in the Arsenal Ship being able to accommodate 3600 missiles. What is most important is such systems are already in development, in use and are well within the technological scope of the British defence industry or available to be bought off the shelf requiring little if any real modification.
If BMD is to be significant role then the vessels will need to have a suitable Radar incorporated within their construction; in Britain’s case R&D would be very low as with the space of such a vessel, and its height, the system as designed for the Type 45 Daring class could simply be transposed.
Self defence systems will need to be incorporated at the beginning, a range of CIWS options could be utilised on such a blank canvass, but at least 4 Phalanx (or suitable equivalents) would be recommended to provide sufficient defensive firepower, supplemented by at least 4 other weapons, such as the BAE MK 110 57mm.
Recent advancements in shell technology, and the continuing development of barrels mean that Naval Gunfire is constantly improving in range, precision, and cost-effectiveness, mounting at least one, if not 2 suitable weapons (Bow and Stern) would provide the vessel, the task force and therefore the government with an increase in scope of options.
If anyone gets a chance after reading this, Lt Dawn Driesback (USN)’s work (http://www.fas.org/man/dod-101/sys/ship/docs/rsnlship.htm) is well worth reading, as it is well researched, and has a lot more space to go into detail on the concept as considered by the USN. Their original consideration of converting a tanker was perhaps understandable considering its timeline, but the options of a container ship are far more suitable for obvious reasons.
Optimum Design Specifications
Power: 4 Rolls-Royce Marine Trent MT30 36 MW gas turbine generator units and 6 Wärtsilä Diesel Generator sets, each an 11MW sets,  supplying power to eight Rolls-Royce Azimuth Thrusters
Range: 12,000nm (20kts)
Speed: 25 kts
Sensors: SAMPSON multi-function air tracking radar, S1850M 3-D air surveillance radar, 2× Raytheon I-band Radar (Type 1047), 1× Raytheon E/F-band Radar (Type 1048), SML Technologies radar tracking system, MFS-7000 sonar (taken from the Type 45 as this will enable the arsenal ship to be seamlessly fitted into air defence role if required)
Weapons: 120 ‘containers’, 2 Medium 4.5in Guns, 4 Phalanx CIWS
Aircraft: 8 EH101 Merlin, 16 A160 Hummingbird UAVs
Flexideck: a space below the ‘weapons’ deck, about 30m x 70m x 7m, or 14,700m3 – which compares favourably with HMS Ocean’s Hangar deck (14,751m3).
The Island/Bridge structure may well be lowered as part of the design as without the requirements of ‘seeing’ over the stacked containers it would be an inefficient addition in its existing form.
Britain is a nation which is more subject to shifts in the world’s global markets and relationships than many others are, as such she does need to be able to ‘flex muscles’ on occasion as part of Britain’s diplomacy. Arsenal ships are a tool for this; they are capable of extending the reach and the security of a Carrier Battle Group ‘CBG’. They could provide an overwhelming ‘first salvo’ at the commencement of operations, whilst not being quite the same style of system as an aircraft carrier they carry such ‘punch’ as to give Britain a real conventional deterrence capability.
The government is currently pursuing a course of decreasing numbers of escorts, but also offering the possibility of more hulls should times get better and the case be well made. Those escorts may well be very flexible frigates – such ships would be excellent vessels for securing Britain’s future  and providing the task forces with the numbers they need. However, if such ships are going to have the range and endurance necessary to operate where Britain will need them to, then they may well not be as powerful as Britain will need them to be for major war fighting roles – which may not be as common, but like riots, when they come along no one professes they were happy they skimped on riot shields and helmets for the police. In such times Britain’s strength will rest on its 2 Queen Elizabeth class Aircraft Carriers, its 6 Daring class Destroyers, its 7 Astute class SSNs and its Amphibious ships (which whilst being crucial to the projection of Britain’s power are not really ‘fighting’ ships). Therefore, a capable Arsenal ship would provide the British government with more capability, with more power and really more deterrence which it would be able to deploy or perhaps activate a reserve as a statement of intent below deploying a CBG – perhaps allowing that to do something even more useful.
Finally there is the role of BMD. Just one ‘container’ could take 30 SM-3 (or Aster 45 if that is what is selected). With Pod Propulsion the Arsenal ship would be able to, literally, sit in place providing a shield for Britain, its Allies and its Task Groups – this is important as often Britain uses its military power for diplomatic currency, BMD is a future core area, for America, Europe and the World. For Britain to have such a system for both its own security and for ‘sharing’ would be a diplomatic, as well as a strategic, boon in future years.
In terms of utility an arsenal ship would be of as much use in preventing conflict as it would be in fighting it, mainly because of its visible capability, but also because of its flexibility. It can provide “Overt Strength and Capability” – simply put it is big and has a lot of missiles. It offers “Pre-emption/Reaction”. Thanks to its size relative to crew numbers it can carry enough food so that all it is really restrained by is fuel and under normal RN rules it will have enough of that to cover a fair distance any time it is required. It also offers “Scalability” – it could launch one missile, it could launch one-thousand missiles. Therefore it provides three out of the four criteria needed for conventional deterrence. Whilst it is not an Aircraft Carrier, and therefore would not have the radius of action that that vessel if so equipped can reach, it is still very good, and far more capable than having nothing. It is more than that, though, if used as an ‘enforcer’ to back up Daring class and other escort vessels. It might well mean that the Aircraft Carrier can be deployed elsewhere. For example, if the Aircraft Carrier is providing support for troops in Afghanistan, the Government would be loath to redeploy it to deal with an emerging crisis, and the Treasury would be unhappy about paying to activate the second aircraft carrier every time something came up. This therefore would provide a method of filling the gap, although on occasion that second carrier will have to be activated. The Queen Elizabeth’s and the Arsenal ships would have service lives of 40 or more years, and a lot can happen in that time. The cost will be more than justified. This though is not the only similarity with aircraft carriers. Like those vessels the arsenal ships will be high enough value targets to justify a significant attack, therefore in wartime it will be necessary to provide them with extra protection. As has been pointed out, they will have a mutually beneficial relationship with aircraft carriers and as they will be operating as part of a Task Group/Task Force there should be enough escorts within that to support them. However they will need support on other occasions.
The usage of arsenal ship is something which may be categorised as being almost more a gunboat in terms of diplomacy, but in war fighting terms being altogether more dangerous. Carrying enough missiles one could easily overwhelm the air defences of most 3rd rate powers, 2-3 would make a serious dent in the air defences of most 1st rate powers. Ultimately an arsenal ship is like an aircraft carrier, something of use in any conflict – and able to scale its contribution to that conflict to the level required by it.
Whilst two would be the minimum procurement, 4 would be the best, although no more than 1 would ever be active in ‘normal times’. These ships are not that complicated to operate, as long as Britain maintains them in good enough readiness. Whilst it is necessary to keep at least one at full level in order to provide an ‘on call’ vessel and to make full use of their strategic potential, having 3 hulls + reserve crews, with 1 regular crew gives the ability to guarantee one in operation and to quickly mobilise above that level if necessary. In this case, the low crew levels pay even more dividends as training can be focused on keeping them at the high levels which would facilitate the rapid activation of the reserve vessels.
It would not just be the 4 Arsenal ships which would have to be procured, but also a vessel type capable of resupplying them. These would most likely be container ships with an extendable crane system fitted. Again pod propulsion is of benefit, as with this both ships could get very close together and hold position for hours if necessary – as well as balance the operations of the crane as long as this is tied into the control system. Thus in even moderately difficult sea-states resupply could be carried out. A further point, and the reason so few auxiliaries are outlined is that, if the ‘containers’ were suitably designed, they would be able to be transported to the nearest friendly harbour to be loaded onto the auxiliaries by civilian container ships – this of course increases the flexibility of the system and enhances the operational logistics of it.
Does an Arsenal ship fit the bill required by likely strategic problems and by tactical limitations currently/projected to affect British operational flexibility? Yes, an Arsenal ship provides the capability of a ‘surge’ of firepower on D-Day and D+1 for the support of initial entry. Its firepower can also be used to help defend other ships by being a massive AA battery, or alternatively be used as the perfect platform (thanks to its height and stability) for providing Theatre Ballistic Missile Defence. It provides a platform which is capable of providing the nation on a budget the full benefits of the development of modern missile technology where future cruise missiles look increasingly to be non-reusable UAVs.
Modular Weapon Concept
Other Sources Used
Phoenix Think Tank References
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