Returning to London, the white-haired evangelist now strode through the corridors of ministries proudly clutching a can of 35mm film, showing his weapon skimming the sea. Eagerly, he awaited authorisation to continue with development of both Upkeep – the dam-bursting version – and Highball, the smaller naval bomb. He chafed for a swift commitment, because for optimum effect an attack on the German dams needed to take place in May, when water levels in the reservoirs were at their maximum height after winter rains and snows.
Instead, however, on 12 February 1943 a blow descended. Ben Lockspeiser told Wallis that AVM Linnell had become concerned that the engineer’s labours on his bombs – nobody used the word obsession, but this was obviously in many service minds – was impeding his ‘proper’ work, development of the Windsor bomber. Linnell did not explicitly oppose the bomb scheme – he was too canny a service politician for that. He merely reported on its speculative character to AVM Ralph Sorley, assistant chief of air staff for Technical Requirements, further emphasising the drain that the project was imposing on resources. Once again, it seems worthy of emphasis that Linnell did not thus play the part of a myopic senior officer flying a desk, but was instead assessing Wallis’s project from the viewpoint of a department besieged by competing demands for facilities to develop new aircraft and weapons systems. Meanwhile Syd Bufton, deputy director of bomber operations, told a 13 February meeting at the Air Ministry that he, as an experienced operational pilot, considered it impracticable to drop Wallis’s bombs in darkness, at low level over enemy territory.
Gp. Capt. Sam Elworthy, a Bomber Command staff officer who attended the same meeting, was charged with reporting on its findings to Harris’s headquarters at High Wycombe, which he did on the following day. The consequence was a note on the ‘bouncing bomb’ drafted by AVM Robert ‘Sandy’ Saundby, senior air staff officer to his chieftain. This, in turn, prompted the C-in-C to scribble one of his most famous, or notorious, judgements of the war: ‘This is tripe of the wildest description … There is not the smallest chance of it working.’ And much more of the same.
Wallis now wrote an anguished personal note to Fred Winterbotham, expressing his frustration: ‘We have just worked out some of our results from the last experiment at Chesil Beach, and are getting ranges nearly twice those which would be forecast from the water tank, that is, with a Wellington flying at about 300 miles an hour and dropping from an altitude of 200 feet, we have registered a range of exactly three-quarters of a mile!!’ He said that the problems of constructing prototypes to be carried by a heavy bomber would be easily solved. ‘It follows that sufficient bombs for the Lancaster experiment (if, say, thirty machines were to be used, to destroy simultaneously five dams, that is, six machines per dam to make certain of doing it) can be completed within two or three weeks.’ He added that modifying the Lancasters would be a far more time-consuming process than manufacturing the weapons, and concluded ‘Yours in great haste,’ adding a handwritten scrawl: ‘Help, oh help.’ It was characteristic of the strand of naïveté in Wallis that in calculating the number of aircraft needed to destroy five dams in enemy territory he was heedless of the possibility that the German defences might remove from the reckoning some, if not all, of the attackers.
Winterbotham responded by writing on 16 February to AVM Frank Inglis, assistant chief of air staff for Intelligence. He extravagantly described the bouncing bomb as an invention ‘for which I was partly responsible’. He asserted that the chief of combined operations and the prime minister were enthusiastic, though there is no shred of documentary evidence of Churchill’s involvement at any stage. He then employed an argument often advanced by estate agents: if the Royal Air Force did not snap up this opportunity, the Royal Navy was eager to do so: ‘My fear is that a new and formidable strategic weapon will be spoiled by premature use against a few ships, instead of being developed and used in a properly coordinated plan.’ He urged ensuring that the chief of air staff was briefed, before it was too late.
Despite Harris’s attitude, and airmen’s continuing doubts about the tactical feasibility, on Monday, 15 February, Gp. Capt. Syd Bufton chaired a further meeting at the Air Ministry, attended by Elworthy, Wallis, Mutt Summers and others, in fulfilment of an Air Staff instruction ‘to investigate the whole [dams] operational project’. Wallis delivered a superbly eloquent sales patter. Upkeep, he said, could be released from a height of 250 feet, at a speed of around 250 mph, at a distance from the target of between three-eighths and three-quarters of a mile. Responding to Elworthy’s concern, expressed on behalf of Bomber Command, about a diversion of precious Lancasters for modification, he said that only one aircraft would be needed for full-scale trials, while those used for an Upkeep attack could be restored to normal operational mode within twenty-four hours. He suggested that while the Möhne dam was the most prominent target suited to Upkeep, the Eder – forty-five miles east-south-eastwards – was also vulnerable.
Most of this was debatable, and some of it flatly wrong. Nobody at the meeting pointed out that even if the Eder represented a suitable target for bouncing bombs, it was unrelated to the Ruhr water system, which was supposedly the strategic objective. The aircraft to carry Wallis’s weapons did not require mere modification, but would instead need fuselages purpose-built by Avro, and could not thereafter be readily returned to Main Force duty. Wallis’s persistence emphasised his gifts as a street-fighter. Where his professional passions were engaged, he was a much less gentle, more ruthless man than was sometimes supposed by those who met him casually. On this occasion, his reputation and conviction carried the day. Bufton changed his mind, renouncing the disbelief he had expressed on 13 February to report in the name of the committee: ‘It was agreed that the operation offered a very good chance of success, and that the weapons and necessary parts for modification should be prepared for thirty aircraft.’ It was thought that as long as the attack took place before the end of June, reservoir levels should be high enough to create massive flooding.
Bufton told AVM Norman Bottomley, assistant chief of air staff for Operations, ‘the prospects offered by this new weapon fully justify our pressing on with development as quickly as possible’. Bottomley, who would play an important role in securing the final commitment to the dams raid, was a veteran networker within the corridors of power. Syd Bufton said of him with wry respect: ‘Nobody could play the Air Ministry organ as skilfully as Norman.’ It was Wallis’s additional good fortune that Bufton and Elworthy – a thirty-one-year-old New Zealander of outstanding abilities who eventually became head of the RAF – were original thinkers, open to new ideas in a fashion that Harris was not. They grasped the terrific theatrical impact that the dams’ destruction would make, surely greater than that of yet another assault on German cities. Churchill once said grumpily, ‘I’m sick of these raids on Cologne,’ to which Sir Arthur Harris’s riposte – ‘So are the people of Cologne!’ – was not wholly convincing.
A weakness of the debate about Upkeep, however, was that it focused overwhelmingly on the feasibility of constructing and dropping the bombs; much less on the vulnerabilities of the water systems of western Germany, the Ruhr in particular. Throughout the Second World War, intelligence about the German economy and industries remained a weakness in Western Allied warmaking, and explicitly in the conduct of the bomber offensive.
Just three days after the Air Ministry meeting, on 18 February, following a telephone conversation with Linnell of MAP, who remained a sceptic, Harris wrote a testy note to Portal, his chief, head of the Royal Air Force. Linnell had told him, he said, ‘that all sorts of enthusiasts and panacea-merchants are now coming round MAP suggesting the taking of about thirty Lancasters off the line to rig them up for this weapon, when the weapon itself exists so far only within the imagination of those who conceived it. I cannot too strongly deprecate any diversion of Lancasters at this critical moment in our affairs.’ Wallis’s bomb, in Harris’s view, ‘is just about the maddest proposition … that we have yet come across … The job of rotating some 1,200 pounds [sic] of material at 500 rpm on an aircraft is in itself fraught with difficulty.’
But Wallis had acquired supporters more powerful even than Harris. After a screening of a new batch of films of his