Alvis produced a variety of armored vehicles for the British Army during the Cold War decades including several car and light tank types built upon a common chassis to fulfill a variety of battlefield roles. In 1973, the British Army began taking a stock of the Alvis FV721 "Fox" armored cars - a three-man, 4x4 wheeled armored system primarily for the for the mechanized scouting role. The vehicles replaced the aged inventory of "Ferret" light-class and the 6x6 wheeled "Saladin" armored cars then in service. The Fox line served British Army forces until their eventual retirement in 1994.
The finalized end-product became a 7.4 ton vehicle with a lightly armored hull superstructure sat upon a two-axle chassis featuring four large road wheels in a conventional configuration. The crew of three included the driver at front-center in the hull with the command and gunner in the hull superstructure/turret proper. Power was served through a Jaguar J.60 No.1 100B gasoline-fueled engine developing 190 horsepower. Operational ranges reached 270 miles with road speeds nearing 65 miles per hour. There was an amphibious capability by way of a flotation screen being arranged. Armor protection was of all-welded aluminum which provided only basic service against battlefield dangers including small arms fire and artillery spray. Unlike other Cold War vehicles, the Fox lacked any NBC (Nuclear, Biological, Chemical) protection for its crew.
Armament was rather strong for a vehicle of this type - a 30mm L21 RARDEN (Royal Armament, Research and Development establishment ENfield) autocannon fitted to the 360-degree traversing turret. The cannon was of a British design and also featured in the tracked Warrior IFV series. The weapon fired a 30x170mm shell of either HE (High-Explosive), APSE (Armor-Piercing, Secondary Effect), or APDS (Armor-Piercing, Discarding Sabot) type with a muzzle velocity nearing 1,175 meters per second out to ranges of 4,400 yards. The cannon was fed by way of three-round cassettes and a total of 99 projectiles were carried on the vehicle. The weapon was coupled to a coaxial 7.62mm L37A2 machine gun in the turret's frontal facing providing a limited anti-infantry measure. The weapon was fed from a supply of 2,600 x 7.62mm ammunition. The turret also carried eight smoke grenade dischargers in two banks of four grenades each straddling the main gun and coaxial armament.
The Fox was a tactically-minded vehicle through-and-through. Its relatively compact size and controlled weight allowed it to be air-transportable to any front in the world - capable of fitting within the belly of a Lockheed C-130 "Hercules" transport or similar. Speed was essential to the survival of the vehicle and crew and the Fox held inherently strong running capabilities. The 30mm cannon gave it good firepower against like-minded vehicles and other soft targets but was limited against the armor showcased by frontline combat tanks. The enemy of the day would have been the Soviet Union and its vast collection of armored vehicles in light, medium, and heavy weight classes - some of which the Fox crew could counter and others that the Fox would have been highly vulnerable against.
The Fox was not heavily produced nor widely exported. Beyond the British Army, usage centered on the armies of Malawi and Nigeria with about 325 total vehicles manufactured by Alvis. Several prototype and developmental variants emerged that went nowhere including a 25-mm turreted form, a machine-gun-only form with a one-man turret, and an Anti-Tank Guided Missile (ATGM) carrier vehicle. Some Fox turrets were reconstituted for use in the "Sabre" tracked vehicle, the work producing 136 models of this form.
Fewer than 100 Foxes are still in use with Malawian and Nigerian forces today though British Army use ended in the mid-1990s.