Tracklink article - The FV 721 Fox & Variants

(This was first published in issue 106 (Summer 2020) of Tracklink, the magazine of the Tank Museum.  The photos used in the original article are Tank Museum copyright, so I have used public domain ones here instead)

British reconnaissance followed two tracks during the Second World War, using both “Scout cars” (very light machine gun armed vehicles exemplified by the Daimler Dingo which relied on speed and low profile to avoid trouble) and heavier “Armoured cars”. The latter were larger, more capable vehicles such as the 2-pdr armed Daimler armoured car or the 6-pdr / 75mm armed AEC, intended to be capable of driving off enemy recce vehicles and providing light fire support.

This pattern continued in the immediate post war period, with the trusty 4 ton Ferret taking over the scout car role from the Dingo while the 76mm-armed 6x6 Saladin was adopted as the heavier armoured car in 1958. The Saladin was a successful design which was widely exported. However, in the late 1960s British policy shifted away from permanent overseas garrisons outside Germany, preferring to deploy UK-based light units to emerging trouble spots quickly by air. Unfortunately, the 12-ton Saladin was too heavy to be air-portable, and was therefore replaced in the early 1970s by the 8-ton CVR(T) Scorpion and Scimitar.

However, the army had also issued a 1965 requirement for a “Combat Vehicle Reconnaissance (Wheeled), intended to be capable of performing some roles at lower cost than its tracked equivalents and reducing the overall cost of the CVR programme. This led ultimately to the FV 721 Fox. 15 prototype vehicles were built in 1967-69, and it was adopted in 1970, with full scale production beginning in 1973 and the first vehicles arriving in operational units in 1975.

Despite being designed by Daimler, in concert with the Military Vehicle Experimental Establishment (MVEE) at Chertsey, the production contract actually went to Royal Ordnance Factory Leeds, with turrets produced by Alvis.

The hull of the Fox strongly resembled an up-scaled version of the Ferret, though the vehicle was much heavier at around 7 tons. It was protected by aluminium armour intended to stop 14.5mm rounds at 200m over the frontal arc, and to stop .30 AP over the rest of the vehicle.

The Fox was a 4x4 vehicle, fitted with run-flat tires. These could be driven on despite multiple punctures, and no spare was carried. It was .powered by the same militarised version of the 4.2 litre Jaguar engine as the Scorpion and Scimitar. This gave it an impressive road speed - officially 65 MPH / 105 KMH, though the author has predictably heard tales of this being exceeded and Foxes breaking the speed limit on motorways. At these speeds, however, the driver's vision port acted like an air scoop, resulting in a strong, cold wind blowing right through the fighting compartment.

Cross country speed obviously depended on terrain, but wasn't necessarily better than the CVR(T) series, and in some cases poorer. Gap crossing was a particular problem compared to the fully tracked designs. It could wade 3 feet / 1 metre without preparation, and could swim using a DD-style flotation screen similar to that used by the Ferret. As with many cold war British vehicles, the flotation screens were often removed in the 1980s when the British Army apparently decided that it wouldn't need to cross rivers without bridges.

Foxes were air-portable; each C-130 Hercules transport could carry three, or two if they were rigged for parachute drop. Although an NBC system had been identified as desirable in the specification, none was fitted as a cost saving measure.

The Fox was fitted with a flat two-man turret with gunner/ radio operator and commander / loader, which accounted for much of the increase in vehicle weight. The turret mounted a 30mm Rarden cannon and coaxial 7.62mm GPMG. Despite some visual similarity, it was a completely different design from the Rarden turret fitted to CVR(T) Scimitar.

Ammunition stowage was 99 rounds of 30mm plus 2,600 rds of 7.62mm, and a four-barrel smoke discharger was mounted on each side of the turret.

The Rarden was a somewhat odd choice for a recce vehicle. It was not stabilised for fire on the move, and was designed to engage Soviet light armour and APCs at long (1,000m+) range. As barrel vibration produced by automatic fire undermined the accuracy required for this, it was a semi-automatic design fed from three-round clips, two of which could be loaded at any one time. As a result, the Rarden had neither the suppressive effect of a fully automatic cannon nor the decent sized high explosive rounds required to successfully engage infantry positions.

In fairness, while a 20-25mm full automatic cannon of the sort used on equivalent German or US recce vehicles and IFVs might have been a better choice for Fox, there was no such weapon in British service and introducing a new calibre into the supply chain would not have been worthwhile for the relatively small number of Foxes in service.

A more realistic option would have been to design Fox to use the same turret as the CVR(T) series, giving the option of either a 30mm turret with the advantage of commonality with Scimitar, or a Scorpion turret with its general purpose 76mm. However, though a common turret with CVR(T) was seen as desirable in the initial specification, the Fox was actually designed with a smaller diameter turret ring, preventing interchangeability.

The rather over-specialised armament was undoubtedly a major factor in Fox' inability to match the export success of Saladin. Most potential customers in the developing world chose to purchase the French AML instead, which was not only cheaper but had a more generally useful armament of either a 60mm gun/mortar or 90mm gun.

321 Foxes were built, but the anticipated foreign sales failed to materialise, with just over 100 being sold abroad, mostly to Malawi (70) and Nigeria (55), with a few to Saudi Arabia and Kenya.

Of the 215 built for the UK, the Armoured Reconnaissance Regiments received 30 each. Two of the recently formed Territorial Army Yeomanry regiments (the Royal Yeomanry and the Queen's Own Yeomanry) received 40 and 30 respectively.

Divisional Armoured Recce squadrons, air-portable battalions and the armoured recce squadrons assigned to Cyprus, Hong Kong and the brigade-sized NATO AMF (L) Quick Reaction Force received 8 each.

The Fox had a poor reputation for overturning; by 1989 nine soldiers and a boy had been killed and 23 injured in 16 separate roll-over incidents, most of which did not involve another vehicle. Trials at MVEE in 1976 indicated these incidents occurred if the driver decelerated while cornering. This caused an oversteer, which if uncorrected caused the rear wheels to break away from the road surface and overturning.

Both this trial and another in 1989 looked at possible modifications such as reducing ride height to make the vehicle more stable. However, they found that these modifications would offer only modest improvement

Fox never saw use in action, and indeed, never fully replaced the Ferret as a light liaison vehicle. With the “Options for Change” review in the early 1990s, which reduced the army by 18%, it was possible to replace the Foxes still in service by reallocating the existing CVR(T) vehicles, and the last examples left service in 1993/4

A number of variants on the Fox were proposed and reached at least the prototype stage. The most important was the FV722 Vixen. This was planned by the army as a companion command & liaison vehicle, based on Fox mechanicals but with a one-man GPMG turret and enlarged hull to accommodate an additional radio operator and equipment. The vehicle was cancelled in 1975 before entering production, but one of the prototypes survives in the Vehicle Conservation Centre at the Tank Museum.

Mounting the GPMG turret used on some FV432s onto a mating collar fitted to a standard Fox hull was proposed as “Polecat”, for use as a less aggressive looking patrol vehicle in Northern Ireland. The idea was dropped, as it had little obvious advantage over the Ferret, which was still in service.

Several prototypes were created by Vickers Defence Systems, who had taken over ROF Leeds, in the hope of generating export sales. All were fitted with smaller one man turrets, presumably to address the roll-over problems but at the possible cost of overloading the commander, who also had to act as the vehicle gunner.

“Panga” was a variant developed for sale to Malaysia with a self-recovery winch, modified hull and stowage and a new turret. It was initially fitted with a one-man Peak Engineering turret mounting a .50 calibre machine gun, and later with a Helio FVT-800 turret mounting the same .50 calibre machine gun plus a 7.62mm coaxial machine gun. Though this offered a useful compromise for those who really wanted an up-gunned Ferret, it failed to sell.

The “Fox 25” mounted the US M242 25mm chaingun and coaxial 7.62mm chaingun with optional stabilisation in a one man turret with 250rds of 25mm and 1,500rds of 7.62mm, but also failed to achieve the hoped-for export sales.

Finally, the “Fox MILAN” was fitted with a new turret mounting either a 7.62mm chain gun or 7.62mm GPMG and twin MILAN launcher, with 8 spare missiles and 2,600rds of 7.62rds carried internally. A variant of this dubbed “Fox Scout” was offered which was simply Fox MILAN with the launcher removed.

Some FV432 APCs were fitted with 30mm Fox turrets on a three-inch spacer ring on the rear deck, replacing the mortar hatches. As this removed most of the troop capacity, they were intended to act as fire support vehicles attached to platoons of regular FV432s, rather than as troop carrying IFVs. Only 13 vehicles were converted, which were assigned to the Berlin Brigade.

Finally, when the Fox went out of service in 1993/4, a significant number were stripped of their turrets, which were fitted into spacer rings on the hulls of FV101 Scorpions, to replace their original 76mm turrets. These conversions were designated as “Sabre”, and also included replacing the coaxial GPMG with a 7.62mm chaingun, replacing the original turret hatches with domed versions for more crew headroom and fitting new smoke dischargers. The vehicle had a larger ammunition capacity than Fox, roughly in line with the Scimitar, carrying 160rds of 30mm and 3,000rds of 7.62mm. 136 Sabres were converted, with no 76mm Scorpions remaining in service. Sabres served from 1995 until withdrawn from 2004.

The FV721 Fox

The Tank Museum's Vixen prototype