'Shadow factories'silent allies of Britain's Air Force. This series of pictures is the first ever made in Britain's 'shadow factories'the centres organised among motor manufacturers throughout the country to aid the Royal Air Force expansion scheme. Less than a year ago the 'shadow factories'were only an idea, but now high-speed work has established buildings on Marstons and given a valuable ally to the aircraft industry. Photo shows, a general view of the aero engine assembly shop at the standard 'shadow'factory at Coventry. 26 October 1937