Roof-spotting nevertheless placed a severe strain on those workers who were sent on rotas to sit for hours on the roof in all weathers when for most of the time there was no direct threat, and from 1941 onwards almost none. The first cohorts were trained by the RAF and then sent back to their localities to train a wider circle of recruits, approximately 4,000 each week. The scheme was not legally binding, and most industries began negotiating with the unions on how to cope with raiding in order to avoid industrial unrest. Schemes of compensation were worked out for the time when air raids really did compel workers to shelter: full pay for up to eight hours a week and half-pay thereafter.127
Workers who found themselves temporarily unemployed as a result of raids, or who suffered injury, could apply to local Assistance Boards and 100,000 payments were made over the course of the Blitz to the injured, in addition to temporary cash payments and clothing coupons for post-raid homeless. Many firms working on war contracts collaborated in Local Production Defence Committees to pool spotter information and provide adequate shelter for the labour force. One set up in Birmingham in March 1941 eventually covered 800,000 workers. To try to limit the time lost in reconstructing damaged premises the government insisted that Reconstruction Panels and Emergency Repair Committees be set up by local firms working with the civil defence authorities and local trade unions. By summer 1941, 120 Panels were in operation and had organized the repair of around 4,000 damaged plants.128The easiest way to limit damage was to disperse production into a larger number of smaller premises or to duplicate vital production in two or more places. Much armaments production lent itself to dispersed production of components, particularly the aircraft industry, so that some degree of decentralization was already in place by the time war broke out. There were also thousands of small engineering and manufacturing firms which could be mobilized to meet the expected production crisis. The dispersal of the aircraft industry became policy at the Ministry of Aircraft Production several months before the bombing began and it continued on a wide scale throughout the Blitz.129
The object was to split up major production units so that there would be at least two and sometimes three production lines for individual components and for finished aircraft; small components or sub-assemblies were to have emergency sites on stand-by in case of air-raid damage; small hangers (‘Hangerettes’) were to be constructed some distance from aircraft plants so that finished planes would not be destroyed before they had been delivered.130 This pattern was followed successfully by most firms. The Castle Bromwich Spitfire plant in Birmingham was split into 23 premises spread over eight towns, each component manufactured in at least three places. The Vickers Weybridge plant bombed in September dispersed to 42 sites within a radius of 20 miles, employing 10,000 workers but no more than 500 on each site. In some cases the firm shared premises: a film studio was used to assemble Wellington bomber wings while films were still being made; a coffin-maker, keen no doubt to profit from the coming business boom, refused to evacuate his premises until compelled to do so and left his tools and equipment for Vickers to use. The Bristol Aeroplane Company dispersed its aero-engine production into the local Corporation Electricity Department, the bus garage and a cigarette factory.131 A more serious problem was dispersing labour to follow the machines. The government set up a scheme to build hostels for 200,000 workers engaged on war orders, but this did little for labour that dispersed itself after a raid. The search for nearby sites for dispersal had the advantage that a firm might miss the bombs but still hold its workforce together. The Bristol Company observed the sensible rule of finding ‘premises not near, and yet not too far’.132