Royal Air Force also acquired and maintained smaller Land Rover fleets during the 1960s and 1970s. The RAF used models for communications, liaison, personnel transport and airfield tractor duties. The Royal Navy's fleet was, understandably, small and consisted mainly of GS-spec and Station Wagon versions for personnel and cargo transport. All British military Land Rovers used the 2.25-litre four-cylinder petrol engine, except the forward control 101 which used the 3.5 litre Rover V8 engine . However, some overseas customers (such as The Netherlands) specified the 2.25-litre diesel unit instead. The Land Rover is also the basis for the Shorland Internal Security Patrol Vehicle developed by Short Brothers. Australia The Australian-made series 1, 2, 2A and 3 were widely used by the Australian Army, Royal Australian Navy and Royal Australian Air Force. Most were GS (General Service) mobility vehicles with variants built as Long Range Patrol Vehicles, ambulances, command reconnaissance cars, fire tenders and ceremonial vehicles. The first was delivered to the Army in 1948 and the series 1 gradually replaced the World War II era Austin Champs and Jeeps. The series 2 was introduced in 1958, the 2a in 1963 and series 3 in 1973. 72 of the series 2 were fitted as an anti-tank "gunbuggy" with a 106mm recoilless rifle. The Land Rover Perentie, commonly thought to be a military variant of the Land Rover Defender, was introduced in 1987, 3 years before the Defender was named in 1990. Over 2,500 four wheel drive and 400 six wheel drive remain in service. New Zealand The New Zealand Army purchased 640 of the Australian-made series 1 between 1951-1953. A similar number of series 2 were purchased in 1959-1962 and a small batch of series 2A in 1965-1967. New Zealand purchased a small number of ex-Australian series 2 and 2A vehicles in 1971-72, out of the pool used by the ANZUK force in Singapore, which were typically re-manufactured by BLMC NZ Ltd in Wellington and hence carry New Zealand build plates. These are commonly called a Land Rover "Skippy" and are distinctive with differently cut guards. The New Zealand Army purchased 566 Series 3 109" V8s, entering service over the period 1982 - 1986. The last Land Rover V8s were phased out of New Zealand service in 2006 when they were replaced by 321 Pinzgauer High-Mobility All-Terrain Vehicles. Minerva Minerva of Belgium produced a version of the Standard Vanguard, under licence