The Bombing War: Europe 1939-1945

British industry and commerce was an easy target. Concentrated in major industrial regions in the centre, north-west and north-east, and in the large port cities from London in the south to Glasgow in the north, industry and commerce lay open to attack once German air forces had secured bases in France and Belgium. Britain was also exceptionally urbanized, with the majority of the population crowded into cities and towns, most of which had swollen in the nineteenth and early twentieth centuries with low-rise, poorly built terraced housing or tenement blocks to house a large industrial and commercial workforce. No planning had ever anticipated heavy bombing attack; cities grew haphazardly, the working classes concentrated in the centres around the docks or industries they worked in, the better off moving to larger, sturdier and more spacious suburban houses. This pattern of growth made individual industrial or port targets difficult to find and hit, but it also maximized the prospect of widespread physical damage to the urban infrastructure and residential housing. The exception was the expansion of new technology manufacture – aircraft, radios, electrical goods, scientific instruments – which developed in southern Britain and London during the interwar years. These new factories were often sited on the outskirts of smaller towns and cities; they were easier to locate from the air than factories in crowded urban areas, but also more dispersed.

Protection for industry and the industrial workforce followed standard civil defence procedure. Shelters were constructed in many key industrial and commercial undertakings (though less effectively in dock areas); the blackout was closely observed, with exceptions for undertakings that could not black out all their operations entirely; many firms ran their own ARP branch, while key equipment and machinery were protected by sandbags and blast walls.¹²¹ These provisions gave limited protection during a raid but in the early attacks did little to protect workers from falling glass from roofs and windows, which accounted for up to 80 per cent of the casualties in the aircraft industry. Instead glass was replaced with solid material, which eliminated all daylight and left workers labouring in artificial light by day and by night.¹²² The necessity for keeping production going for as long as possible, even during red alerts, led to the introduction in the autumn of 1940 of roof-spotters whose role was to watch for local gunfire and approaching aircraft before alerting the rest of the workforce to take shelter. The initial loss of production time was substantial. The steel industry calculated that up to the end of August bomb damage to plant had caused a loss of only 1,000 tons of steel products, but alerts had cost 147,000 tons. This was more than was lost when heavy attacks were eventually made on the steel industry in December.¹²³ The spotter scheme was approved by the War Cabinet in September. It was provoked initially during the months of the Battle of Britain by the need to keep aircraft production going at all costs, which was the responsibility of Lord Beaverbrook, the first Minister of Aircraft Production. Beaverbrook favoured conscripting all workers to stand to their duties ‘as soldiers and sailors are required to conform to the orders of the Commanding Officer’, but discussions between employers and unions led to the adoption of the look-out scheme.¹²⁴

The necessity for the system was demonstrated on the day agreement was reached. At the Vickers aircraft plant in Weybridge, south of London, a surprise attack by a handful of dive-bombers on 3 September 1940 killed 89 workers and resulted in the disappearance of a further 3,000 and a cut in production by two-thirds.¹²⁵ Roof-spotting had the advantage that it gave more precise warning of impending attack than reliance on official alerts, and it cut to a fraction the amount of time lost by needlessly sending the workforce to shelter. In early November 1940 the Minister of Labour, Ernest Bevin, forwarded to Churchill statistics from one firm which had instituted ‘Air Watching’ to show what it could achieve. Between 24 August and 19 October there had been 124 air-raid alerts, lasting a little over 233 hours; instead of losing the equivalent of ten working days, the roof-spotting had resulted in a loss of just one hour twenty minutes.¹²⁶ Calculations made over the war in industrial localities suggest gains of 60–70 per cent in work-time by carrying on after the siren. In total, an estimated 11 million man-hours were saved.