Munitions handling on the Royal Navy’s aircraft carriers
In a previous article, we looked at the new jetty being constructed in Scotland for transferring munitions to and from Queen Elizabeth Class aircraft carriers. It is a complex subject but here we make a cursory examination of some of the weapons and their handling arrangements onboard the ships themselves.
The QEC were designed from the outset to take advantage of modern logistics technology to ease the movement of munitions and stores onto and around the ships. The drive to adopt automation wherever possible was part of a major design effort to reduce personnel numbers, the biggest single through-life cost of a warship. This design goal has been successfully achieved, reducing the manning requirement by about 65% compared with conventional designs. In theory, the weapons handers and the facilities onboard should be able to meet the demands of a maximum-sized ‘CV wing’ of up to 36 F-35 jets and around 24 helicopters flying around 110 sorties per day. (It will probably be a long time time, if ever, before 60 aircraft are embarked). There are four main elements needed to safely store, transport and prepare potentially high volumes of munitions. The magazines, the Highly Mechanised Weapons Handling System, (HMWHS), the weapons preparation areas and interconnecting weapon lifts.
In the first half of the 20th Century, the RN acquired much painful experience, both in peacetime and in action, of what happens when ammunition is either mishandled or magazines and access routes are poorly designed. Despite the advent of modern insensitive munitions that are vastly safer to handle, the highest standards of blast mitigation and fire suppression have been specified for the QEC weapon areas.
The positioning of the weapons magazines and their lifts are one of the first considerations when designing an aircraft carrier. The four main magazines are located below the waterline in the central third of the ship. A series of lifts bring munitions up to the preparation areas, the hangar or onto the flight deck. When the QEC embark their initial weapons outfit at the Northern Ammunition Jetty, the munitions will be craned off lorries in their containers onto the lowered aircraft lifts, taken through the hangar, strapped to pallets and then struck down into the magazines via the lifts. During replenishment at sea, munitions supplied by the RFA Solid Stores Support ship will be embarked using the movable highpoint heavy RAS rigs in the hangar, before being taken below. To mitigate the effects of blast, fire or flood, there are a total of 19 heavy mechanised doors fitted to the magazines and lifts. There are six different types of doors and hatches which vary in size, the largest being 6 x 3m, weighing around 6 tonnes.
It is interesting to note that weapon elevator design is not straight forward. The latest US aircraft carrier, USS Ford has 11 electromagnetic lifts designed deliver munitions at double the speed of conventional design. Amongst the many show-stopping technical problems with this innovative ship, only two of the munition elevators are working at the time of writing. HMS Queen Elizabeth is also highly innovative but has encountered far fewer problems than the Ford.
The robot railway
The HMWHS that has been developed for the QEC is the first naval application of land-based automated systems used in commercial warehouses. Babcock was engaged by the ACA to begin the HMWHS design in 2003 and was awarded the manufacturing contract in 2008. Thales was employed to integrate the system on the ships but Babcock remains the design authority and have been contracted to provide on-going support through the life of the system. Not only does the remotely-controlled system vastly reduce the number of sailors needed to handle weapons, but can also deliver weapons faster and in a safer working environment than using conventional man-handling. It is also well suited to transport expensive, sophisticated, relatively delicate missiles.
The HMWS is made up of 56 ‘moles’ which are electrically-propelled units that lift and carry pallets bearing the payload. Moles are carried on a network of straight tracks that run fore and aft and athwartships. There are two types of mole, one for athwartship movements and one for longitudinal movements. Overlapping transfer positions allow moles to move payloads between each other, so it is possible to transport the loads anywhere within the magazines and to and from the lifts. There are multiple stowage locations offering flexibility in loading. There is a measure of redundancy in the system to allow for action damage. A weapon can be selected from the deep magazine and brought up to the preparation area at a push of a button. Air-weapons are kept permanently in their specialised containers strapped to pallets on shock-proof mountings in the magazine until needed and are not unboxed until they arrive in the preparation areas, prior to being loaded onto the aircraft. The pallets that are moved by the moles are more than 5m in length, allowing them to handle the largest air-launched weapons available today or likely to be developed in future and can comfortably move 4 boxed ASRAMM missiles at a time.
Flight in Air Material (FIAM)
The composition of the QEC embarked air group will vary considerably and have a very diverse range of munition requirements. The Merlin Mk2 is equipped with the Sting Ray Torpedo and occasionally carries depth charges. Wildcat helicopters may be embarked for force protection and will mount the Sea Venom/ANL and the Martlet lightweight Multi-Role Missile (LMM). The Army Apaches are armed with CRV7 Rockets, 30mm chain gun, Hellfire missiles and will eventually have Brimstone 2 missiles.
When the QEC are operating in the Littoral Manoeuvre role and embarking Royal Marines they will have a variety of automatic weapons and ammunition carried by each man. On occasions, they may also carry heavy weapons into battle including 60mm & 81mm Mortars, Javelin and the Light Anti-tank Weapon (NLAW). (To maximize troop numbers carried by helicopter from the carrier, heavier weapons may need to be taken ashore from other ships by landing craft). There are also magazines for the ship’s self-defence weapon ammunition which includes 30mm cannons, 20mm Phalanx CIWS, a variety of machine guns and decoys and pyrotechnics.
By far the greatest volume of munitions normally embarked on the carrier will be to arm the F-35. In time we can hope that a broader variety will be integrated with the aircraft but initially it will carry four main weapons; ASRAAM, (Advanced Short Range Air-to-Air Missile) SPEAR 3 (Select Precision Effects At Range – Capability 3), Meteor (Beyond Visual Range Air-to-Air missile) and Paveway IV laser-guided bombs (LGB).
ASRAAM has been in service with the RAF for some time and was first test-fired by an F-35 in 2017, achieving initial operational capability for land-based operations in December 2018. The current version of ASRAAM will be used until 2022 when it is due to be replaced with an improved version which will be compatible with the F-35 Block 4 software upgrade. The upgraded ASRAMM has a better seeker head and has shares components with the Sea Ceptor (CAAM) missile. Each ASRAMM costs around £200k.
The F-35B can carry two Meteor missiles in their internal weapons bay for missions requiring stealth capabilities or a total of six, if the external underwing hardpoints are also used. Unlike conventional rocket-propelled air-air missiles, Meteor is akin an air-launched cruise missile, using a ramjet that allows it to vary speed and maximise its range. Detailed comment on the role and performance of each weapon is beyond the scope of this article, but Meteor, when mated to the very stealthy F-35B will provide a very powerful capability. Able to knock out aircraft far beyond visual range, it is particularly relevant if confronting an adversary using an area access deal strategy. The 3.7-metre Meteor only just fits inside the F-35B internal weapons bay and MBDA is having to modify the tail fins to fit by reducing their height and increasing their length, to retain the same wing area. Stored in specialised protective containers which include self-test equipment, if a fault is detected, operators are alerted and the sealed container is returned to MBDA for repair. Once unboxed, Meteor has an airborne carriage life of 1,000 hours before any maintenance is required. Estimated to cost around £2 million per missile, Meteor is around ten times the price of ASRAMM which has been produced at scale for many years. Integration and testing of the Meteor on F-35 is due to be completed by the end of 2024.
SPEAR 3 is a stand-off weapon designed to attack small targets from distance. A small turbojet and folding wings give it a range of at least 130Km. Designed with the ground attack role in mind, for now it also offers the only credible means for the F-35 to attack shipping. Despite its subsonic speed, a saturation attack of 8 missiles could be used to attack small-medium size warships from beyond the range of their surface to air missiles. SPEAR 3 integration with F-35 is due to be completed in 2025.
To date, the RN has limited experience in using the QEC weapon handling system but early signs are good that the HMWHS and access routes will be fast, efficient and safe, once it has to cope with heavy operational demands. Over the 50 year lives of the QEC, aircraft and their weapons will continue to evolve. The large size of the ships and their magazine capacity means they are well placed to accommodate these developments.