The largest of Vickers’ wartime bomber designs to actually make it to the hardware stage, the Windsor was smaller than the Victory Bomber and other concepts would have been, yet was an impressive aircraft, and one that might have been pursued farther had the war lasted longer.
The original basis for the Windsor was Specification B.5/41, for a heavy bomber with pressurization for high altitude operations. Vickers’ Type 433 design was essentially a stretched Warwick with a larger wing and a Wellington VI style pressure cabin. Two prototypes were ordered, but the program was then revised to meet the evolving Specification B.3/42, and the Windsor design became the Type 447, with Merlin 61s (later 65s) and a substantially higher gross weight.
After investigating a number of defensive armament schemes, and trials on a Warwick testbed to prove out the concept, it was decided to fit the Windsor with a pair of 20mm Hispanos in the rear of each outboard nacelle, these weapons being remotely controlled from a station in the tail.
The prototype Windsor, DW506, flew from Farnborough in October 1943. Intended solely to prove the airworthiness of the design, this aircraft had no operational equipment, and was written off in a forced landing on 2 March 1944. By that time, the second aircraft, the Merlin 65-powered DW512 was flying, followed in July of that year by NK136, with the nacelle barbettes and a revised structure. A fourth prototype, NN670 was started, but cancelled postwar despite nearly being complete.
The Type 483 operational model, had it ever seen the light of day, would have had Merlin 100 engines at the start, although the Rolls-Royce Griffon and even the Clyde turboprop were options. There were several studies for airliner derivatives, including pressurized transatlantic models, but these were not pursued.
Windsor scale 3-view Flieger Revue 1980-08 p.362
Tony Buttler British Experimental Combat Aircraft of World War II includes close-ups of the nose and nacelles of DW506, DW512’s annular radiators, a 3-view of the proposed Clyde-powered variant, and a series of shots showing the wreckage of DW506