The Type 950 Vanguard was a British short/medium-range turboprop airliner introduced in 1959 by Vickers-Armstrongs, a development of their successful Viscount design with considerably more internal room. The Vanguard was introduced just before the first of the large jet-powered airliners, and was largely ignored by the market. Only 43 were built, ordered by Trans-Canada Airlines (TCA) and British European Airways (BEA). After only about 10 years service TCA experimentally converted one of theirs to a freighter configuration, calling it the Cargoliner. This was considered successful, and in the early 1970s most were converted to freighters, those from BEA becoming the Merchantman. These freighters remained in service for many years, with the last one (G-APEP) only retiring in 1996.
The aircraft was designed to a BEA requirement for a 100-seat aircraft to replace their Viscounts. The original Type 870 design was then modified when TCA expressed their interest in the design as well, and Vickers returned the updated Type 950 that filled both requirements.
The main difference between the Viscount and Vanguard was the construction of the fuselage. The Vanguard started with the original Viscount fuselage, but cut it off about half of the way up from the bottom, and replaced the top section with a larger-diameter fuselage to give it a double bubble cross-section (similar to the Boeing Stratocruiser). The result of the larger upper portion was a roomier interior, with increased cargo capacity below the floor.
With this larger, and heavier, fuselage came the need for a new engine to lift it. Rolls-Royce delivered their new Tyne design with a nominal 4,000 hp (3,000 kW) (as compared to the Viscount's Dart of about 1,700 hp (1,300 kW)).
This allowed for a much higher service ceiling and cruise speed, the Vanguard had a service ceiling almost twice that of the Viscount. The Vanguard was one of the fastest turboprops ever and was faster than the present day Saab 2000 or de Havilland Canada Dash 8.
The first Type 950 prototype flew on 20 January 1959, entering service in 1961. The last Merchantman (Vanguard) was retired by Hunting Cargo Airlines on 30 September 1996 and donated to Brooklands Museum on 17 October.