Vickers Wellington - Design and Development

Design and Development

The Wellington used a geodesic construction method, which had been devised by Barnes Wallis inspired by his work on airships, and had previously been used to build the single-engine Wellesley light bomber. The fuselage was built up from 1650 elements, consisting of aluminium alloy (duralumin) W-beams that were formed into a large framework. Wooden battens were screwed onto the aluminium, and these were covered with Irish linen, which, once treated with many layers of dope, formed the outer skin of the aircraft. The metal lattice gave the structure tremendous strength, because any one of the stringers could support some of the weight from even the opposite side of the aircraft. Blowing out one side's beams would still leave the aircraft as a whole intact; as a result, Wellingtons with huge areas of framework missing continued to return home when other types would not have survived; the dramatic effect was enhanced by the doped fabric skin burning off, leaving the naked frames exposed (see photo).

In one case, a German Bf 110 night-fighter attacked a Wellington returning from an attack on Münster, Germany, causing a fire at the rear of the starboard engine. Co-pilot Sergeant James Allen Ward climbed out of the fuselage in flight, kicked holes in the doped fabric of the wing for foot and hand holds to reach the starboard engine, and physically smothered the burning upper wing covering. He and the aircraft returned home safely, and Ward was awarded the Victoria Cross for his actions.

The geodesic structure also gave a very strong but light structure for its large size, which gave the Wellington a load and range to power ratio advantage over similar aircraft, without sacrificing robustness or protective devices such as armour plate or self-sealing fuel tanks.

However, the construction system also had a distinct disadvantage in that it took considerably longer to build a Wellington than other designs using monocoque construction techniques. Also, it was difficult to cut holes into the fuselage to provide additional access or equipment fixtures. The Leigh light, for instance, was deployed through the mounting for the absent FN9 ventral turret. Nevertheless, in the late 1930s Vickers succeeded in building Wellingtons at a rate of one a day at Weybridge and 50 a month at the Chester factory (located at Broughton in North Wales). Peak wartime production in 1942 saw monthly rates of 70 achieved at Weybridge, 130 at Broughton and 102 at Blackpool.

The Wellington went through a total of 16 variants during its production life plus a further two training conversions after the war. The prototype serial K4049 designed to satisfy Ministry Specification B.9/32, first flew as a Type 271 (and initially named Crecy) from Brooklands on 15 June 1936 with chief test pilot Joseph Summers as pilot. After many changes to the design, it was accepted on 15 August 1936 for production with the name Wellington. The first model was the Wellington Mark I, powered by a pair of 1,050 hp (780 kW) Bristol Pegasus engines, of which 180 were built, 150 for the Royal Air Force and 30 for the Royal New Zealand Air Force (which were transferred to the RAF on the outbreak of war and used by 75 Squadron). The Mark I first entered service with No. 9 Squadron RAF in October 1938. Improvements to the turrets resulted in 183 Mark IA Wellingtons, which equipped the RAF Bomber Command heavy bomber squadrons at the outbreak of war. The Wellington was initially outnumbered by its twin-engine contemporaries, the Handley Page Hampden and the Armstrong Whitworth Whitley, but ultimately outlasted them in productive service. The number of Wellingtons built totalled 11,461 of all versions, the last of which was rolled out on 13 October 1945.