Tracklink Article - The Swingfire guided missile and its launch vehicles
(This article originally appeared in Issue 103 (Summer 2019) of Tracklink, the magazine of the Tank Museum. The photos which originally accompanied it belong to the Tank Museum, so I've used equivalents from the public domain)
Thinking about the firepower deployed by British armoured regiments during the latter half of the cold war generally conjures images of the 120mm guns mounted on the regiments' 50+ tanks. However, for much of the period these were significantly augmented by Swingfire missile systems.
Swingfire was not the first wire guided missile system used by the Royal Armoured Corps. Limited numbers of Malkara missiles were mounted on specialist Humber Hornet launch vehicles (based on heavily modified Humber Pigs) from 1958, and were used by the RAC (1) from 1962.
The Hornet's main role within the RAC was to provide anti-tank support for the RAC parachute squadron, which was initially provided by 2 RTR (2) and then manned on a rotating basis by all RAC regiments.
However, while the Malkara missiles were capable of killing any contemporary tank, they were so large (94kg / 206lb) that even the dedicated launch vehicles could only carry two missiles plus two reloads, and they were difficult to guide to the target.
Malkara was replaced in the early 1960s by Vigilant, a significantly lighter missile with a much easier to use guidance system. Vigilant was mounted on Mk 2/6 Ferrets, which were little modified apart from having a vigilant missile container mounted on either side of the standard turret, outside the armour. The majority served with the Independent Armoured Reconnaissance Squadrons, on the basis of one missile vehicle per troop.
Though lightweight, Vigilant's key problem was its short range of 1,375m and it began to be replaced by Swingfire from 1966.
Individual Swingfire missiles weighed 27 kg, and with a 170mm HEAT (3) warhead, it was able to seriously inconvenience any Soviet tank of the period, though as with any shaped charge warhead its effectiveness was reduced by spaced armour, explosive reactive armour or modern composites.
The original Swingfire missiles used the same “Manual Command to Line of sight” (MCLOS) guidance system as the Vigilant, with the controller using a thumb joystick to steer the missile to the target centred in the sight. This was later upgraded to an improved “Semi-Automatic Command to Line of Sight” (SACLOS) system, which automatically flew the missile into the target centred in the sight. Anecdotally, Swingfire was one of the easiest guided missiles to use for its period.
A key advantage was that the controller could dismount the portable sight unit and carry it up to 100m from the launch vehicle, connected by cable. Combined with the missile's ability to make a rapid turn of up to 90 degrees into the line of the sight after launch, this meant the launch vehicle could fire while completely concealed behind cover, and the operator would be hard to spot since he would be well away from the launch signature.
This avoided a drawback identified with the Soviet-made “Sagger” missile in the Vietnam and the Arab-Israeli wars – tank crews quickly learned to spot the launch signature and pour fire onto it. Even if the missile controller survived, the incoming fire usually made him flinch or drop fully into cover, causing the missile to go uncontrolled and crash into the ground before it reached the target.
Swingfire had a stated maximum effective range of 4,000m, which allowed it to engage targets beyond the 2,000 – 2,500m effective range of most tank guns at the time. However, under adverse conditions such as strong headwinds, the missile might exhaust its fuel by 3,600 metres. The operator needed to acquire the missile after launch before starting to guide it, and the system had an effective minimum range of around 5-600m.
This made it very difficult to use effectively in close terrain such as woodland, made worse by the possibility of the command wire snagging on obstacles. More importantly, even with the missile travelling at 650 KPH (400 MPH), it still took 12 seconds to reach 2,000m and 26 seconds to reach the 4,000m maximum distance, and targets might not remain visible for that long.
The army quoted an accuracy of 85% under range conditions, though this was an average of numerous tests with scores of 72-92%, influenced heavily by wind conditions, operator experience and so forth.
Missiles could be fired within 2 minutes of the launch vehicle halting, though setting up the separate launch control unit for detached use away from the vehicle took another 3-4 minutes. The guidance wire unspooled as the missile travelled, and the launch vehicle could not fire on the move even if the missile controller had not dismounted with the sight unit.
Missiles were issued in sealed cannisters to protect the sensitive electronics inside, and the entire cannister was loaded into the launcher bin unopened. The system never quite attained the 95% reliability required by the original specification; it actually averaged around 87% in tests, though this fell to as low as 80% in some “bad batches” or missiles which had been shaken around by prolonged cross country travel.
Swingfire was mounted on three types of armoured vehicle in RAC service.
FV438 Swingfire
The FV438 Swingfire was the most common launch vehicle for the system. It was based on the FV432 armoured personnel carrier, but instead of carrying an infantry squad it had two elevating launch bins, each holding one missile. Fourteen missiles were carried in total, and the crew could reload each launch bin in 20-30 seconds from inside the vehicle. Combined with missile flight time, this gave an effective rate of fire of around one missile per minute.
The fixed launcher bins could not be traversed, but the ability to steer the missile after launch allowed each vehicle to cover a 180 degree fire arc. Each vehicle had a crew of three – driver, commander / missile operator and loader / alternate missile operator. However, this was a poor set-up, as it was very hard for the vehicle commander to maintain situational awareness while guiding missiles and his visibility was poor from the launch control position.
When the FV438s initially entered service in the 1970s they were operated as integral anti-tank components of infantry battalions and RAC regiments. However, from 1977 the specialised anti-tank role transferred to the Royal Artillery, which concentrated the FV438 vehicles into four independent RHA (4) batteries, one for each armoured division in BAOR (5).
Each divisional RHA Anti-tank battery had 30 launch vehicles forming 6 troops, plus a Light Aid Detachment. These were made up of 1 x troop of 6 FV102 Strikers which supported the Divisional Reconnaissance Regiment, 2 x troops of 6 FV438 Swingfire each, which supported the two armoured regiments, and 3 x troops of 4 FV438 Swingfire each, which supported the divisions' three infantry battlegroups
This situation remained until 1984, when the Royal Artillery relinquished the anti-tank role. The FV438 vehicles then returned to the RAC, formed into a single nine vehicle Guided Weapons troop for each armoured regiment.
Given how quickly a launch vehicle could expend its missile load, 10 spare missiles per launch vehicle were held as a first line resupply within the battle groups.
FV102 Striker
The FV102 Striker was developed as a lightweight air portable launch vehicle to support reconnaissance units. It was based on the CVR (T) (6) chassis used by the Scorpion family, and strongly resembled the the FV103 Spartan APC version of the family. Whereas Spartan could carry 4 infantrymen (usually specialists such as fire controllers and AA or ATGM missile teams) the Striker carried five Swingfire missiles in a single elevating bin at the rear of the vehicle.
Five reloads were carried inside the vehicle (i.e. 10 missiles total) but the crew had to dismount and potentially expose themselves to fire to reload the external launcher bin. This took around four minutes normally, passing the rounds through the rear door, or at least five minutes in NBC protective suits and passing missiles up through the commander's hatch to avoid contact with contaminated ground.
The ability to fire five missiles without reloading meant the loader role could be deleted, so while Striker still only had three crew, they could split the jobs far more effectively into driver, missile operator and vehicle commander, allowing the latter to maintain situational awareness and spot targets far more effectively.
When Striker was introduced in 1975 it used a 4.2 litre Jaguar petrol engine, but this was later replaced under the 1988 CVR (T) life extension programme with a 5.9 litre Cummins diesel.
It entered operational service in 1976 with the Royal Artillery of BAOR, but as with FV438 they transferred to the Royal Armoured Corps in 1984 where they served in Armoured Reconnaissance Regiments.
These went through several reorganisations during the period. They typically contained three Medium Reconnaissance Squadrons (each containing three sabre troops of 4 Scorpion or Scimitar CVR(T) plus a Guided Weapons troop with 4 Striker and a support troop of 4 Spartan) plus a Close Reconnaissance Squadron with 5 troops of 8 Fox armoured cars.
The Close Reconnaissance Squadron was ultimately replaced with a fourth Medium Reconnaissance Squadron when the Fox was removed from service.
FV712 Ferret Mk 5
Since the Army knew that the FV102 Striker would not be available until the mid-1970s, an interim vehicle was needed to replace the Vigilant-armed Ferret Mk 2/6 in the air droppable role. This stopgap resulted in the FV712 Guided Weapons Ferret. This entered service at the end of the 1960s, and was based on the four wheel Ferret armoured car. It used the hull of the Mk3 Ferret (upgraded from the original Mk 1 & 2 versions with larger wheels, better armour and a more robust suspension) but fitted with a large flat aluminium turret rather than the usual machine gun turret.
The new turret mounted a GPMG in the centre, and four Swingfire missiles in a pair of elevating launch bins, one to either side of the turret. Two spare missiles were carried in stowage boxes on either side of the crew compartment.
Although the turret theoretically had the advantage of 360 degree traverse compared to the 180 degrees covered by the fixed launchers on the other vehicles, it was manually rotated using a geared handwheel, and took between 16 seconds and a minute to complete a rotation, depending on direction and vehicle angle.
The FV712 had a two man crew, consisting of a driver and an overworked missile operator / commander, who would have found it almost impossible to maintain any form of situational awareness while guiding missiles, and suffered from a very poor view when the vehicle was closed down. Space was so limited that even the control cable allowing the sight to be used away from the vehicle was only 50m long, rather than the 100m cable used by the other launch vehicles.
Only 32 were built, and served with the RAC parachute squadron (12 vehicles) and the Hong Kong squadron (6 vehicles). They were withdrawn in 1977, and replaced by FV102 Striker.
Other Swingfire vehicles
Swingfire's light weight and low recoil meant it could be mounted on on a variety of light vehicles, at least experimentally. This included mounts for Lynx helicopters, a tubular steel “pallet mount” holding four missiles ready to fire and two spare rounds beneath which could be used as a ground mount or installed on a ¾ ton Landrover and even a single-round launcher mounted on what was essentially a golf trolley.
The RAC also investigated fitting Chieftain tanks with Swingfire, allowing them to engage targets beyond main gun range. The kit would have featured four launch tubes mounted on the left rear of the turret, and guided by the tank commander. Given the vehicles' role, it would not have featured a dismountable sight unit, and spare rounds would have been carried on the engine deck. Perhaps unsurprisingly, the idea did not proceed.
Finally, concepts were developed for a pair of Swingfire-armed missile tanks. The first would have been a simple conversion of surplus Centurions, fitted with 16 launch tubes attached in rows down both sides of the vehicle and reloaded from a further 16 rounds carrier internally. The second envisaged using a newly constructed Chieftain chassis fitted with a new body mounting an FV438-style twin launcher, which could be reloaded under armour using 30 reloads carried inside. Both versions would have replaced their normal turrets with a small one man turret mounting a 20mm cannon for close defence, but neither left the drawing board.
Replacement
The FV102 Striker was the last Swingfire-equiped vehicle in British service. It saw combat in the Gulf and Iraq wars, and destroyed at least one Iraqi T-55 tank during the latter conflict. It was withdrawn in 2005, when Swingfire was replaced (along with the lighter MILAN used by the infantry) by the US-made FGM-148 Javelin missile in mid-2005.
Although the Javelin has a lighter warhead than Swingfire, it has several advantages over the older missile, including the ability to lock on to a target before being launched as a “fire and forget” weapon rather than needing to be guided to the target, tandem warheads to defeat reactive armour and a top attack mode that allowed it to perform a “pop-up” to hit the thinner top armour of a target regardless of which side of the target was facing the launch vehicle.
Comments
Post a Comment