to MVEE-1318B with strict quality control) was fitted from 1978. To fit inside the transport aircraft of the time, the vehicle's height had to be less than , its width had to be less than . To meet the ground pressure requirement of five psi, the tracks had to be wide. The width also dictated the engine used – it had to fit next to a driver in full winter clothing. Thus the engine compartment could only be wide. No tank engines in production or development at the time were suitable, so the Jaguar 4.2-litre petrol engine was used. This was modified to use military-grade fuel, with a compression ratio lowered from 9:1 to 7.75:1 and a single Solex Marcus carburettor, resulting in a power output reduction from 265 bhp to 195 bhp. The driver position, being located at the front of the vehicle alongside the engine, dictated that the turret would have to be at the rear. The fire support version, armed with a 76 mm gun, was named Scorpion as the rear-mounted turret suggested a sting in the tail. Following the example of Alvis predecessor vehicles Saladin, Stalwart (load carrier) and Saracen (personnel carrier), all CVRTs started with the letter 'S'. The other vehicles were named to reflect their function; Striker anti–tank guided weapons, Spartan armoured personnel carrier; Samaritan ambulance; Sultan command and control and Samson recovery vehicles. In addition, the British General Staff had requested another vehicle armed with a 30 mm cannon, which became Scimitar. In 1967, Alvis was awarded the contract to produce 30 CVR(T) prototypes. Vehicles P1–P17 being the Scorpion prototypes, P18–P30 were prototypes of the other six CVR(T) versions. Having to work under strict cost limitations imposed by the Ministry of Defence, the first prototype was completed on time and within budget on 23 January 1969, after extensive hot and cold weather trials in Norway, Australia, Canada and Abu Dhabi. In May 1970, the CVR(T) was accepted into British Army service; a contract was agreed for 275 Scorpions and 288 Scimitars. The first production Scorpion being completed in 1971, initial delivery to the British Army was in January 1972. By 1986, the United Kingdom had taken delivery of 1,863 CVR(T)s. Total production for the British Army was 313 Scorpions, 89 Strikers, 691 Spartans, 50 Samaritans, 291 Sultans, 95 Samsons and 334 Scimitars. Life Extension Programme In 1988, Alvis plc was awarded a £32