It is hard to overstate the stress under which the bomb’s begetter existed in those days. He was still spending many hours on the design of the Windsor, Air Ministry specification B.3/42. In the mind of Sir Charles Craven, this was much more important than Upkeep and Highball: contracts for a big new bomber promised immense rewards for Vickers, contrasted with those to be gained from building a few bombs. Moreover, confusingly for Wallis and for the entire Whitehall hierarchy, Craven was intermittently seconded to assist and work in the Ministry, so that it was sometimes unclear to all concerned whether he spoke as the engineer’s employer, or as the voice of officialdom. On 18 February, Wallis worked until 7.45 p.m. at the National Physical Laboratory. Next morning, he met the Admiralty’s director of weapons development, then at 2.30 p.m. saw MAP officials to discuss unspecified aircraft de-icing problems. At 4 p.m. he was back at Vickers, where at 5.30 p.m. there was another screening of his bomb-test films, following which he drove to Dorking with Admiral Renouf. On the next morning, a Saturday, he worked in his office at Burhill, then attended more meetings in the afternoon. On Sunday he was confined to his home at Effingham with a migraine, such as he often and unsurprisingly succumbed to.
Next day, Monday the 22nd, he drove with Mutt Summers to High Wycombe for a personal audience with Sir Arthur Harris. Sam Elworthy claimed credit for persuading the C-in-C to meet the engineer. He wrote to Harris after the war, saying emolliently that ‘your scepticism of what seemed just another crazy idea was certainly shared by your staff’. But the clever group-captain had been impressed by what he heard about Upkeep – and he also saw which way the wind was blowing at the Air Ministry.
Harris was no fool. For all his bombast, he grudgingly acknowledged that he had masters who must sometimes be appeased. He knew that Portal had authorised the modification of three Lancasters to carry Upkeep. While the words ‘whether the Commander-in-Chief of Bomber Command likes it or not’ were never articulated, they were understood. The Chief of the Air Staff wrote to Harris on 19 February: ‘As you know, I have the greatest respect for your opinion on all technical and operational matters, and I agree with you that it is quite possible that the Highball and Upkeep projects may come to nothing. Nevertheless, I do not feel inclined to refuse Air Staff interest in these weapons.’
That morning of the 22nd at High Wycombe, Wallis was subjected to a predictable barrage of invective: ‘What is it you want? My boys’ lives are too precious to be wasted on your crazy notions.’ Yet it is unlikely that Harris would have received Wallis at all had he not already recognised that he would have to give way, and provide resources for an operational trial of Upkeep. Having viewed the films, he professed grudging interest.
Wallis succumbed to a brief surge of optimism. This was shattered, however, on his return to Weybridge. He received an order to present himself immediately at the London office of Vickers, his employers, for an audience with the company’s chairman. Craven, without inviting his visitor to sit down, declared brusquely that MAP’s Linnell had complained that Wallis had become a nuisance; that his bouncing bombs had become a serious impediment to the vastly more important Windsor project. The air marshal had explicitly demanded that Craven call a halt to Wallis’s ‘dams nonsense’.
This was what the Vickers chairman now did. A shouting match followed, in which the designer offered his resignation, and Craven shouted ‘Mutiny!’ They parted on terms of mutual acrimony. Moreover, while Wallis was not often a grudge-bearer, he never forgave AVM Linnell for the part he played in attempting to kill off Upkeep. He went home despondent to Effingham, sincerely determined upon resignation, as was scarcely surprising after the humiliation he had suffered. Craven, whose responsibility was to Vickers, can scarcely be blamed for his behaviour, after being told by the Ministry of Aircraft Production – upon whose goodwill his company depended for orders – that its chiefs were tired of his nagging, insistent assistant chief designer (structures). Why should such people as Linnell, Craven and indeed Harris have accepted at face value the workability of a new weapon which represented a marriage of technologies of extreme sophistication with others of almost childlike simplicity, which when fitted to a Lancaster caused it to resemble a clumsy transport aircraft with an underslung load?
Yet Wallis knew that, whatever Craven said about the MAP’s view of Upkeep, the Admiralty remained enthusiastic about Highball. On 26 February, by previous arrangement he drove to London to attend a meeting that was to be chaired by the now-detested Linnell, to discuss measures to improve the aerodynamics of what some described as ‘the golf mine’ – because of its resemblance to the shape of a golf ball. After Wallis was told that Roy Chadwick of Avro, designer of the Lancaster, would also be attending, he understood that Craven had got things all wrong the previous day: the RAF had not abandoned Upkeep.
When the delayed meeting finally convened at 3 p.m. that Friday, in Linnell’s office at MAP on London’s Millbank, it was to receive tablets from on high. Sir Charles Portal was not only chief of air staff and a former C-in-C of Bomber Command; he had also been among the first enthusiasts for attacking Germany’s dams. He was troubled by doubts about Sir Arthur Harris’s obsession with destroying cities. His reservations were founded not upon moral scruples – no senior wartime airman admitted to those – but instead on uncertainty about its war-winning potential. Portal never summoned the courage to sack Harris, even in the winter of 1944–45, when his subordinate directly defied targeting orders. But the CAS was always at heart a proponent of attacking precision objectives, if means existed to make such a policy work. Now, Barnes Wallis promised to provide these; to make possible fulfilment of the RAF’s 1937–38 dream, of an assault upon Germany’s dams.
The array of brass assembled at the MAP on the afternoon of 26 February 1943 was told that the chief of air staff had given his assent, or rather had issued an order, to proceed with immediate development of Upkeep. Portal wrote: ‘I think this is a good gamble.’ The reaction of Sir Charles Craven, who was also present, is unrecorded. He must have felt privately foolish, if not furious, following his ugly dressing-down of his designer four days earlier. What the CAS demanded, however, Vickers must seek to provide.
Linnell, too, can scarcely have enjoyed announcing – against his own strong personal conviction – the decision to prioritise Upkeep over the Windsor bomber. ‘The requirement for bombs,’ this MAP potentate now said, ‘has been stated as one hundred and fifty to cover trials and operations’ – one hundred and twenty were eventually made. It was further stated that studies of the German dams showed that 26 May – just three months ahead – was the latest date in 1943 on which they could plausibly be attacked. It would thus be necessary to build thirty ‘Provisioning’ Lancasters, as they had been codenamed, and to produce a sufficiency of bombs by 1 May, to provide reasonable time for aircrew training for the operation. The MAP’s budget for research on Upkeep, which in August 1942 had been raised from £2,000 to £10,000, was now further increased to £15,000, and later again on 1 April to a princely £20,000.
While Portal made a personal commitment that enabled Upkeep to be unleashed, it deserves emphasis that he placed a relatively modest bet. Only air-power fantasists could suppose that a single squadron of Lancasters, a maximum of twenty bouncing bombs, would cripple the entire water system of the Ruhr, an aspiration demanding a much larger force even if Wallis’s weapons were half-successful – almost no new weapons system in history has performed better than that. Yet a squadron was all that the Air Ministry would authorise, in the face of Harris’s virulent hostility, a limited supply of aircraft and uncertainty about the viability of Upkeep. British war-makers have for centuries displayed a weakness for ‘gesture strategy’ – deploying a disproportionately small force as a means of displaying interest in fulfilment of a disproportionately large objective. Mass matters, however, to the success of all military operations, and in this case it would be lacking. Though the RAF neither then nor later admitted this, its commitment to an assault on Germany’s dams was marginal, a tiny fraction of the forces that set forth upon almost nightly attempts to burn cities. To borrow a modern phrase, this would be a niche operation.
Wallis’s