Task: Question Answering
Input (English): Passage: Trafford Park was largely turned over to the production of war materiel during the Second World War, such as the Avro Manchester and Avro Lancaster heavy bombers, and the Rolls-Royce Merlin engines used to power the Spitfire, Hurricane, Mosquito and the Lancaster. The engines were made by Ford, under licence. The 17,316 workers employed in Ford's purpose-built factory had produced 34,000 engines by the war's end. The facility was designed in two separate sections to minimise the impact of bomb damage on production. The wood-working factory of F. Hills & Sons built more than 800 Percival Proctor aircraft for the RAF between 1940 and 1945, which were flight tested at the nearby Barton Aerodrome. Other companies produced gun bearings, steel tracks for Churchill tanks, munitions, Bailey bridges, and much else. ICI built and operated the first facility in the UK able to produce penicillin in quantity.As an important industrial area, the park suffered from extensive bombing, particularly during the Manchester Blitz of December 1940. On the night of 23 December 1940, the Metropolitan-Vickers aircraft factory in Mosley Road was badly damaged, with the loss of the first 13 MV-built Avro Manchester bombers in final assembly. The new Ford factory producing aircraft engines was bombed only a few days after its opening in May 1941. Trafford Hall was severely damaged by bombing, and was demolished shortly after the war ended.In the December 1940 air raids, stray bombs aiming for Trafford Park landed on Old Trafford football stadium, the nearby home of Manchester United, but this air raid only resulted in minor damage and matches were soon being played at the stadium again. On 11 March 1941, however, stray bombs aimed at Trafford Park fell onto Old Trafford for a second time, causing serious damage to the stadium. It was comprehensively rebuilt after the war and re-opened in 1949, until which time Manchester United played their home games at Maine Road, the stadium of Manchester City in Moss Side.At the outbreak of war in 1939 there were an estimated 50,000 workers employed in the park. By the end of the war in 1945 that number had risen to 75,000, probably the peak size of the park's workforce; Metropolitan-Vickers alone employed 26,000. 
Question: The 17,316 workers employed in Ford's purpose-built factory had produced 34,000 engines by which war's end?
Output (English): the Second World War.