Both the new aircraft and the new bombs were slow to join Bomber Command in any significant numbers. Only 41 heavy bombers were produced in 1940 and 498 in 1941, compared with an output of 4,703 medium bombers.140 These were modest figures against the plans drawn up in spring 1941 to create a force of 4,000 heavy bombers by the spring of 1943. Bomber production had taken a back seat during the summer and autumn of 1940 when priority went to fighter aircraft for defence against German raids. The Minister of Aircraft Production, Lord Beaverbrook, was later blamed by the Air Ministry for trying to kill off ‘the Big Bomber programme’, but this ignored the serious technical problems encountered in trying to develop and get into service large and complex aircraft in a matter of months.141 In May 1941 Portal informed Beaverbrook’s successor, John Moore-Brabazon, that he did not want any further heavy bombers developed during the war because of the long lead time between designing a bomber and seeing it into service.142 The ‘4,000 Plan’ was always unrealistic. It called for production of at least 1,000 bombers a month over a two-year period, more than twice the number produced during 1941 and 1942. It was already evident by the summer of 1941 that bomber production had hit a serious bottleneck. The RAF pinned its hopes on being able to persuade the United States to make up the shortfall.
The efforts to get America to solve Britain’s bomber crisis went back to the early spring of 1941, when Lend-Lease was finally approved. The RAF delegation in Washington had the challenging task of persuading the American service chiefs to accept the transfer of substantial quantities of modern aircraft, and in particular heavy bombers, from their own rearmament programme. Air Vice Marshal Slessor negotiated the aircraft requirements with the Army Air Corps, commanded by General Henry ‘Hap’ Arnold (‘Hap’ for ‘Happy’). The American offers were enshrined in what became known as the ‘Slessor-Arnold Agreement’, a generous commitment, subject to circumstances, to supply Britain on a 50–50 basis from all American aircraft production.143 The agreement failed, however, to address the problem of the heavy bomber, where Britain’s deficiency was most marked and American output still in its infancy. Arnold visited Britain in April 1941 and was told that the British aircraft industry could not produce more than 500 of the 1,000 heavy bombers needed each month. The United States was asked to fill the gap. Arnold agreed that up to four-fifths of American heavy-bomber output could go to Bomber Command by summer 1942, but this would consist of fewer than 800 aircraft. By then it was evident that the American Air Force would renege on the original agreement as relations with Japan deteriorated. At the staff discussions at the Churchill-Roosevelt Argentia summit at Placentia Bay in August 1941, Arnold refused to confirm the American offer. In his diary he noted: ‘What the British want – my God what a list and what things – no promises.’144 During September the full extent of American withdrawal from the initial Slessor agreement became clear. The bombers destined for Britain had been fitted with the Norden bombsight, which was still embargoed for British use, and ensured that the bombers could not be released to the RAF. Instead of the 800 bombers expected, the British were granted 238 with no promise of any further deliveries beyond July 1942. It marked the end of the Slessor agreement and the end of any prospect of developing a force of 4,000 bombers.
The most urgent problem facing Bomber Command was the search for some form of electronic aid for navigation without which even larger numbers of bombers would still have restricted striking power. In the summer of 1941 the problem was not simply the failure to hit a precise industrial or railway target, but the inability, under conditions of night, poor weather and German defences, to find an entire city. Given that these failures almost nullified what Bomber Command was trying to do, the long period that elapsed in trying to find appropriate tactics or technology is difficult to explain. The technology itself was not exotic, and the capacity to interfere with German electronic navigation in the winter of 1940–41 made evident that British science was capable of replicating German practice. The Telecommunications Research Establishment had begun work on a system using radio pulse transmitters in 1938, known as ‘G’ (for Grid), but usually described as ‘Gee’. The system worked by sending pulses from three ground stations which could be measured on a cathode-ray tube carried in the receiving aircraft; where the coordinates intersected it was possible to estimate between a mile and six miles the aircraft’s position. Like the German system, it had limited range and was less accurate the further away from the ground stations the aircraft was. It worked generally no further than western Germany. The system was shown to Bomber Command in October 1940 and service trials began in May 1941. The first experimental operation using ‘Gee’ was conducted by two Wellington bombers on 11 August 1941, but one crashed on German soil. The delay in introducing ‘Gee’ was partly a result of delays in the production of one of its valves, but the main problem was the argument between those who favoured putting ‘Gee’ in a small number of target-finding aircraft, which would lead in the rest of the force, and those who argued that it was something which should be made widely available for the benefit of all. This was to become a central conflict in deciding the best tactics for attacking German cities and it undermined efforts to develop a more appropriate operational system more rapidly. The use of ‘Gee’ was postponed until enough sets were available to supply much of the Command; its first operational use was not until 8 March 1942.145
The arguments over the introduction of ‘Gee’ also involved the best tactics to adopt to achieve Bomber Command’s new objectives and to counter the threat posed by German anti-aircraft defences. Since the summer of 1940, when the German Air Force had relied principally on anti-aircraft fire, a more sophisticated defensive system had been constructed combining anti-aircraft fire, night-fighters, searchlights and radar. The original air defence system, like that of the British, had been based on the assumption that attacks would come by day. The German defenders soon realized that the pattern of British bombing was difficult to predict. A few daylight raids were made, but most raids were small night attacks defined because of their modest scale as nuisance raids (Störangriffe), whose object, it was assumed, was to intimidate the population and disturb the rhythm of industrial labour. Then came heavier raids in spring 1941, again scattered and unpredictable but deliberately directed, so the German authorities believed, against ‘open cities and residential areas’ as simple terror attacks.146 Night attacks meant that anti-aircraft fire, without radar assistance, was effectively blind. The decentralized pattern of British raiding made it difficult to know what to protect. German air observation posts were set up around 15–20 kilometres from predicted target areas, but night-time conditions reduced the prospect of accurate information. The numerous sound detectors used in conjunction with searchlights were found to be vulnerable to the British tactic of throttling back the engines to dampen the noise as aircraft approached a potential danger zone. (British crews also believed that throwing empty milk bottles or beer bottles out of their aircraft confused enemy equipment. The ‘whistling bottle’ was said to interfere with sound location and triggered the searchlights to switch off.)147 For the German side a concerted defence was difficult to mount because RAF bombers failed to damage essential war-economic targets, which were guarded by ‘air defence strongpoints’, and instead scattered and their loads over an extended area with few evident objectives. The Butt Report could essentially have been written by the Germans months before.148
On 3 March 1941 the German Air Force established a new command system to cope with the British offensive. General Hubert Weise was appointed Luftwaffenbefehlshaber Mitte (Air Force Commander, Centre) with the task of constructing an effective air defence wall around northern Germany. He centralized air defence by taking over the defensive functions of the Luftgaue (Air Regions) in northern, western and central Germany. On 1 May 1941 he set up the first dedicated night-fighter organization under General Josef Kammhuber as Jagdführer Mitte (Fighter Leader, Centre) and integrated it with the searchlight and anti-aircra
ft artillery batteries deployed in northern Germany and the Low Countries. A ‘Kammhuber Line’ – generally known in German as Himmelbett (heavenly bed) – was constructed from the Swiss border, through the Belgian city of Liège to the German-Danish border, consisting of a series of map ‘boxes’ in each of which a small number of fighters were controlled by a new and improved radar, codenamed Würzburg.149 Only one fighter could be controlled at a time, but once a bomber had been identified it became with practice easier to direct a fighter to combat position. The night-fighters were not yet fitted with AI radar, like British night-fighters. But the German version, codenamed Lichtenstein, was in the process of development and was finally installed in 1942, though it was not popular with pilots, who assumed the large external aerials would reduce performance. The searchlights were numerous and powerful, but it was found they were wrongly positioned. From mid-1941 they were spaced out at least three kilometres apart to ensure a better prospect of trapping a bomber overhead. The anti-aircraft batteries were gradually supplied with the new Würzburg radar, which, like the British experience with anti-aircraft radar, proved difficult to operate with poorly trained personnel and was prone to technical problems. As radar-guided fire improved, the batteries found the supply of radar too slow. By spring 1942 only one-third of anti-aircraft guns had the new apparatus.150
The fighters worked in two distinct ways. The first echelon engaged in what was called ‘dark’ night-fighting, using radar-equipped ground controllers to guide them to their target; behind the night-fighter boxes was a line of searchlights, soon to have their own radar guidance system, which was used by a second echelon of night-fighters for ‘light’ fighting against bombers trapped in a searchlight cone. No dedicated night-fighter had been developed before the start of British bombing, but the Junkers Ju88, the Messerschmitt Me110 and the Dornier Do17 (later Do217) were converted to the role in 1940 and formed the mainstay of the force thereafter. The night-fighter force had expanded by the start of 1942 to four night-fighter groups totalling 265 aircraft, a modest fraction of the total German Air Force establishment. The British tactic of allowing bomber crews to work out their own route to the target meant that the raiding group became spread out in area and time, making it easier for each German night-fighter to locate and destroy them in their individual boxes. By September 1941, night-fighters assisted by searchlights had claimed 325 enemy aircraft, while ‘dark’ night-fighting added a further 50.151 Anti-aircraft fire claimed 439 aircraft shot down between January and September 1941, though many of these, if true, were from daylight operations mounted by other RAF commands.
The steady increase in losses might well have pushed Bomber Command to adopt new tactics. The decision to focus on incendiary bombing of urban areas ought to have encouraged a tactical shift to larger and more concentrated raids. The advantages were obvious: the concentration of the bomber stream would mean that the individual fighter boxes in the Himmelbett line and the searchlight wall behind them would be swamped; most bombers would be through the line and to relative safety until they reached one of the inland gun belts. Above all, tight formation and a bomber stream would allow a raiding group to drop all its bombs in a short period of time, maximizing their impact and reducing bomber casualties.152 Opinion in the Air Ministry and the Air Staff nevertheless remained divided. Peirse favoured retaining the loose, decentralized formations and encouraging the crews to find the best way to their target and back. A tighter formation, it was claimed, would place a heavier burden on pilots, while it would become easy prey for the ‘dark’ night-fighters waiting in the Kammhuber Line. Bomber Command had reached an impasse, exaggerating the threat from the German defences, yet incapable of responding creatively to the new strategic imperatives.
Peirse’s lacklustre command finally produced a growing chorus of criticism. The Directorate of Bombing Operations insisted that Bomber Command begin serious operational preparations for large-scale incendiary attacks on enemy cities. Assessments were produced by Air Intelligence of the degree of necessary concentration based on German practice. The Air Warfare Analysis Section tested the possible effects of heavy salvos of incendiaries on a large-scale map of the City of Westminster to see what damage might be done. Around 100,000 incendiary bombs were now considered a suitable load to begin a major conflagration. Zone maps of German cities were drawn up showing the most densely populated residential areas (Zones 1 and 2a), the suburban areas (Zones 2b and 3) and the outer industrial area (Zone 4), with recommendations to deliver the maximum bombload on the two central zones where large numbers of workers were packed together and to leave the industrial areas alone. In October Peirse was sent detailed instructions on carrying out an experimental incendiary raid on a German city. The subsequent raid on Nuremberg on the night of 14–15 October proved an inauspicious start: most aircraft bombed a small town outside Nuremberg and only one Stirling hit targets in the city, injuring six people. No major fires were started.153
The most dangerous criticism came from the top. In response to a paper from Portal in late September 1941 spelling out the long-term plan for 4,000 bombers, Churchill replied: ‘It is very disputable whether bombing by itself will be a decisive factor in the present war. On the contrary, all that we have learnt since the war began shows that its effects, both physical and moral, are greatly exaggerated.’154 Portal objected that he saw no reason to regard the bomber ‘as a weapon of declining importance’, but went on to ask Churchill whether the RAF should now be looking for a new strategic concept. Churchill’s reply in early October was equivocal. On the one hand he assured Portal that bombing was still a strategic priority, but on the other he played down the likelihood of a satisfactory strategic outcome:
I deprecate, however, placing unbounded confidence in this means of attack, and still more expressing that confidence in terms of arithmetic … Even if all the towns of Germany were rendered uninhabitable, it does not follow that the military control would be weakened or even that war industry could not be carried on. The Air Staff would make a mistake to put their claim too high.155
This was the start of Churchill’s growing disillusionment with what bombing could deliver. His initial enthusiasm had been based on a very limited understanding of what bombers were currently capable of achieving. As a politician he was interested in the prospect that air attack might provoke a political reaction in Germany, but the erratic intelligence available suggested that bombing had done very little to undermine German war-willingness, while the clearer evidence nearer home showed that the British political system and social structure had survived intact. Morale was now viewed by the RAF less as a means of political pressure, more as a war of economic and social attrition or, as Portal put it, ‘interference with all that goes to make up the general activity of a community’. But to Churchill, who had imagined a more immediate and politically significant effect from bombing, the idea of long-term and unpredictable attrition was an unexciting prospect.
Peirse made one final effort to redeem his reputation and that of his force. On the night of 7–8 November 1941 he marshalled the largest force yet sent out on operations over Germany, some 392 aircraft, including 43 heavy bombers. The weather forecast was poor but he persisted with the operation. The chief target was Berlin but of the 169 bombers sent there, only 73 reached the capital where they distributed their bombloads, with limited effect. Only 14 houses were destroyed, 9 people killed and 32 injured. Other bombers attacked Cologne, which suffered five deaths and two houses destroyed, and Mannheim, where no bombs fell at all. During the night 37 bombers were lost, more than 9 per cent of the force; for the task force sent to Berlin the loss rate was 12.4 per cent. One squadron recorded in its diary that the mission was ‘practically abortive’.156 Berlin was not bombed again until January 1943. Peirse was summoned to see Churchill on the following day and told to suspend the offensive over the winter to conserve his shrinking force. Small raids were carried out when possible, but the assault on morale ordered in the summer of 1941 e
ffectively came to an end with little achieved. The Air Staff investigated the Berlin raid and concluded that Peirse had been negligent in sending out his force in the knowledge that high winds, storms and iceing would be met by the crews. The decision was taken in December to replace him and he was finally removed in early January 1942 after Churchill had been shown the documents on the disastrous Berlin raid. On 8 January Peirse was appointed to command Allied air forces in Asia, facing the Japanese. Air Vice Marshal John Baldwin, commander of 3 Group, became his temporary replacement until a new commander-in-chief was in post.157
The Bombing War: Europe 1939–1945 Page 38