The Vickers Wellington was a twin-engine, medium bomber designed in the mid-1930s at Brooklands in Weybridge, by Vickers-Armstrongs' Chief Designer, R.K. Pierson. It was widely used in the first two years of World War II, before being replaced as a bomber by much larger four-engine designs like the Avro Lancaster. The first main production variant was the Mk IC, The next significant variant was the Mk III which featured the 1,375 hp (1,205 kW) Bristol Hercules III or XI engine and a four-gun tail turret, instead of two-gun. A total of 1,519 Mk IIIs were built and became mainstays of Bomber Command through 1941. Length: 64ft 7in Wingspan: 86ft 2in Height: 17ft 6in Empty: 18,556 lb Maximum takeoff: 34,500 lb Speed: 261 mph Ceiling: 22,700 ft Range: 2,040 mi Armament: Eight 7.7mm machine gun; 2,014 kg bombs.