It was impossible for these facilities to be secret, though they were camouflaged after hostilities began. They were war
materiel production facilities built in "the shadow" of motor industry plants to facilitate technology transfer to aircraft construction and run, for a substantial management fee, in parallel under direct control of the motor industry business along with distributed facilities. General
Erhard Milch, chief administrator of the
Luftwaffe, was in Britain in the autumn of 1937 inspecting new shadow factories in
Birmingham and
Coventry, RAF aeroplanes and airfields.
Background Up until the middle of 1938, the Air Ministry had been headed by Lord Swinton. He had been forced by Prime Minister
Neville Chamberlain to resign his position due to a lack of progress in re-arming the
Royal Air Force, the result of obstruction by
William Morris, Lord Nuffield. Swinton's civil servants approached their new boss, Sir Kingsley Wood, and showed him a series of informal questions that they had asked since 1935 on the subject, such as those posed to
Morris Motors with regard to aircraft engine production capability at its
Cowley plant in
Oxford. As it turned out, the specialised high-output engines required by the RAF were made by
Armstrong Siddeley,
Bristol Aeroplane,
Napier & Son and
Rolls-Royce, all of which employed a high number of sub-contractors. Despite their new factories, protestations by
Wolseley Aero Engines (Nuffield) and
Alvis were ignored. Their products were not required. Engines were specified primarily by the designers of aircraft though the Air Ministry did sometimes specify the engine to be used. Nuffield did participate after Wood's appointment, providing the
Castle Bromwich Factory and promising a thousand Spitfires by June 1940 but, after two years, management was so poor that when June 1940 arrived not one Spitfire had been produced there. Castle Bromwich was withdrawn from Nuffield by
Lord Beaverbrook. the
Minister of Aircraft Production, and placed under the wing of
Vickers-Supermarine.
Implementation The plan had two parts: • Development of nine new factories. The government would build and equip the factories. Motor car companies would be asked to gain experience in the making of engine parts so, if war broke out, the new factories could immediately go into full production. • Extensions to existing factory complexes to allow either easier switching to aircraft industry capability, or production capacity expansion. bombers was Standard Motor Co, Canley (Coventry) and de Havilland's own sites in Hertfordshire. Under the plan, there was government funding for the building of these new production facilities, in the form of grants and loans. Key to the plan were the products and plans of Rolls-Royce, whose
Merlin engine powered many of the key aircraft being developed by the Air Ministry, as well as
Bristol Hercules radial engine. Bristol Aeroplane would not allow shadow factories to build complete engines, only components. The exception was
Austin. The first motor manufacturers chosen for engine shadows were: Austin,
Daimler,
Humber (Rootes Securities),
Singer,
Standard,
Rover and
Wolseley. In the event Lord Nuffield took Wolseley out of the arrangement and Singer proved to be in serious financial difficulty. The buildings were sheds up to long lit either by glazed roofs or "
north-lit". Office accommodation was brick, and wherever possible faced a main road. These buildings were extremely adaptable and would remain part of the British industrial landscape for more than 50 years. One of the largest was Austin's Cofton Hackett, beside their
Longbridge plant, started in August 1936. long and wide, the structure covered . Later a airframe factory was added, then a flight shed by was attached to the airframe factory. light bombers were built at Rootes Blythe Bridge and Speke. The new factory buildings were models of efficient factory layout. They had wide, clear gangways and good lighting, and they were free of shafting and belt drives. The five shadow factories in Coventry were all in production by the end of October 1937 and they were all making parts of the
Bristol Mercury engine. By January 1938 two of those shadow factories were producing complete airframes. In July 1938 the first bomber completely built in a shadow factory (Austin's) was flown in front of Sir Kingsley Wood, Secretary of State for Air. It was said eight shadow factories constructing aircraft components were in production in or near
Coventry in February 1940. As the scheme progressed, and after the death of Austin in 1941, the Directorate of Air Ministry Factories, under the auspices of the
Ministry of Aircraft Production (MAP), gradually took charge of the construction of the buildings required for aircraft production. In early 1943 the functions of the directorate of Air Ministry Factories were transferred to the
Ministry of Works. ;Scotland There were three waves of construction of shadow factories and only the third and smallest reached Scotland in the shape of the factory at
Hillington producing Rolls-Royce's Merlin engines. Ferranti's factory in Crewe Toll, Edinburgh will have been secret. ;Empire Similar plans were introduced in Canada, Australia, New Zealand and South Africa. ==List of shadow factories ==