by Andrew Brown
Mountbatten had been convinced by Steer-Webster’s arguments and felt it was important to establish a unanimous acceptance of the War Office’s Mulberry design. Apart from needing a consensus on the Mulberry harbours, the CCO was also determined to set a coherent planning strategy for the whole invasion. At the Casablanca Conference in January 1943, which he had attended, it was agreed between Churchill and Roosevelt that a Supreme Allied Commander (SAC) should be appointed to be in charge of the allied invasion of Western Europe. It was further agreed that the SAC should be British, and Churchill gave the nod to Sir Alan Brooke, Chief of the Imperial General Staff. Mountbatten realized that his own role would be diminished once the SAC was formally appointed, but by the summer this had still not happened. In June, Mountbatten sensing that his influence on planning for the invasion was about to be curtailed, called a conference, codename ‘Rattle’, in Largs – a small seaside town on the Clyde estuary.9 The Allied top brass at ‘Rattle’ resolved that the assault landing beaches would be somewhere between Cherbourg, on the Cotentin peninsula to the west, and Dieppe, to the east.
During the early summer, naval architects and engineers continued to work on Habbakuk in close cooperation with Bernal and Perutz. The requirements for the vessel became ever more demanding: it had to have a range of seven thousand miles and be able to withstand the biggest waves ever recorded in the world’s oceans. The Admiralty wanted it to be torpedo-proof, which meant a hull at least forty feet thick. The Fleet Air Arm decided that not just fighters but heavy bombers should be able to take off from its deck, which had to be fifty feet above water and two thousand feet long. Perutz recalled that ‘steering presented the most difficult problem. At first, we thought that the ship could be steered simply by varying the relative speed of the motors on either side, like a plane taxiing along the ground, but the Navy decided a rudder was essential to keep it on course. The problem of suspending and controlling a rudder the height of a fifteen-story building was never solved.’10 Early in July 1943, detailed drawings for the ice Leviathan appeared and are reproduced above.
1943 Admiiralty blueprints for Habbakuk, the giant aircraft carrier to be constructed from Pylrete. Public Record Office (ADM 1/15236)
At COHQ, Pyke was no longer satisfied with the original function of a berg ship as a landing strip, and now advocated a more direct offensive role for the unsinkable vessels: the occupation of enemy harbours. Egged on by Pyke, Sage called for a change in existing strategy to suit Habbakuk, rather than trying to fit Habbakuk into existing strategy. The Royal Navy captain chairing a Habbakuk committee meeting in July was unmoved by their fantastic schemes.11 Mountbatten was meant to have said, jokingly, that ‘COHQ is the only lunatic asylum in the world run by its own inmates’, but it seems that now he was perturbed by the wildness of Pyke’s and Bernal’s latest ideas. A week or so after the meeting, the CCO sent for Perutz, whose technical reports always conveyed a sense of urgency and realism; he asked him one question: ‘Who should represent Habbakuk at a high-level meeting?’ Without hesitation, Perutz replied, ‘Bernal’ as ‘the only man who possessed the technical knowledge, the intellectual stature, and the persuasiveness to stand up to the war leaders.’12 Mountbatten took Perutz at his word, and told Sage he ought to go to Canada again. Sage replied, ‘I suppose you must have your reasons.’ The CCO said: ‘I think you should go fairly soon. In fact, I have arranged for you to go this afternoon.’13
Following the invasion of Sicily in July 1943, Italy appeared poised to collapse. Churchill was intent on the immediate invasion of Italy, as well as attacking other points in the ‘soft underbelly of the Axis’. The Americans were by now adamant that the primary focus should be on the cross-Channel landing. Churchill therefore proposed another Anglo-American Conference to discuss the progress of the war, and Quebec was soon agreed as the meeting place for what became known as the Quadrant Conference. Mountbatten was instructed to bring a small contingent from Combined Operations with him. Bernal would find himself the only civilian scientist included (Cherwell, for once, was not at Churchill’s side). The British entourage of about two hundred ‘captains and kings’14 included several Cabinet ministers and the chiefs of staff (COS). They sailed from the Clyde aboard the Queen Mary on 5th August. Amongst them were two inspirational war heroes – Brigadier Orde Wingate and Wing Commander Guy Gibson – whom Churchill wished to present to Roosevelt. On the first day at sea, Mountbatten ordered Sage to get a haircut so that he might cut a respectable figure in front of the Chiefs of Staff and told him to stay out of the way until he was called upon.
Sage was not kept skulking around the ship for long. On Saturday 7th August, the COS Committee met, and the provision of artificial harbours was one of the main items on the agenda. They heard from Captain Hussey of COHQ on proposed modifications to merchant ships for launching amphibious vehicles and on ways of getting tanks ashore. Mountbatten, with his usual touch of theatricality, then informed his fellow chiefs that ‘the greatest expert in the world’ on artificial harbours happened to be on board. Bernal was produced from below decks and spoke for a short time on two of the Admiralty’s proposals for making temporary breakwaters.15 Sensing that these senior men of action would prefer a demonstration to a lecture, Bernal suggested that they should move to an adjacent bathroom. The tub was filled with water, and he made a flotilla of about twenty boats from newspaper. He invited his audience, which had grown considerably from the original five chiefs, to imagine the boats at one end of the bath were just off the coast of France, and asked a naval lieutenant to make waves at the other end of the bath with a back brush. The fleet became waterlogged and sank; Bernal said: ‘That, gentlemen, is what will happen without an artificial harbour.’16 He then took a Mae West lifebelt and laid it across the bath close to a second fleet. Calling for more waves, they all watched as the lifebelt damped the vigorous motion of the water and his newspaper boats stayed afloat. In the words of Lord Mountbatten: ‘There was no doubt that Bernal’s demonstration, together with his extremely able exposition of the subject, helped tip the scale with the Chiefs of Staff and made Mr Churchill more enthusiastic than ever.’17
The Prime Minister was not one of the onlookers in the bathroom, but heard about it from the COS. He soon sent for the professor to ask him some questions. They sat at either end of a long table. Churchill had difficulty hearing Sage’s rather high-pitched, reedy voice, and growled: ‘I can’t hear a word you are saying. Come and sit up here, Bernal.’18 Following this comical day of ‘bathroom and bedroom scenes’,19 Sage retired to his bunk, a stowaway no longer. Mountbatten sent a cable to COHQ reporting that ‘the Prime Minister has taken the most enormous personal interest in the artificial harbours’.20
Sage was back in front of the COS two days later to discuss Habbakuk. The naval architects had expressed Pyke’s original concept of a floating airstrip in three alternative versions. Habbakuk I (soon discarded) would have been made of wood. Habbakuk II was closest to the COHQ model and would be a very large, slow, self-propelled vessel built of Pykrete reinforced by steel. Habbakuk III was a smaller, faster version of Habbakuk II. Air Chief Marshal Portal asked about potential bomb damage to Habbakuk III. Bernal suggested a certain amount of deck covering would be forced off, but could be repaired by some kind of flexible mat. It would be more difficult to deal with bomb holes in the centre portion, though the roof over the hangers would be made proof against 1,000 kilo bombs.21 With regard to the bigger Habbakuk II, Bernal thought no one could say whether it would prove a practical proposition, until a large-scale model was built and tested in Canada in the spring of 1944. He had no doubt about the suitability of Pykrete, but constructional and navigational difficulties remained to be overcome.22 The COS seemed satisfied with Bernal’s answers, and agreed that Habbakuk should remain a high priority – the Prime Minister to be informed accordingly. They agreed that the CCO would write a memorandum on the subject to be tabled at Quadrant.
During the historic voyage on the Queen Mary,
the COS apprised Churchill of the plan to land the allied armies on the Calvados coast of Normandy, during the early summer of 1944, to establish the long-awaited Second Front. Named Operation Overlord, this would be the greatest invasion from the sea in military history. Churchill saw the provision of artificial harbours and air superiority as the keys to success. The Mulberry harbours and some type of floating airstrip seemed to him to be vital engineering projects that would underpin Overlord. He was finally convinced that a cross-Channel invasion would be feasible in the next year.
When the ship docked at Halifax, Nova Scotia, Churchill noted with surprise, in spite of all attempts at secrecy, large crowds were assembled on the quayside to greet the British arrivals. The scenes were repeated at every station that their train passed through on the journey to Quebec. Before the formal start of the Quadrant Conference, Churchill travelled with his daughter to Hyde Park, the Roosevelt family home in upper New York State, to spend a few days in private with the President.23 The two leaders discussed many weighty policy matters, including a secret, bilateral agreement (the Quebec Agreement) for the ‘full and effective’ interchange of information and collaboration on atomic weapons. Their talks also resulted in key decisions about supreme military commands. Despite his previous promise to Brooke, Churchill recognized that the Americans would be providing the bulk of the invasion force for Overlord so that the Supreme Allied Commander should be American – General Eisenhower would be the eventual choice. Fired by his conversations with Wingate on board ship, Churchill wanted to intensify the war in South-East Asia; Roosevelt took little persuading that this command should be given to Lord Mountbatten, who was soon appointed Supreme Allied Commander South-East Asia (SACSEA).
The venue for Quadrant was the Chateau Frontenac – a luxurious hotel that towers above Old Quebec and has magnificent views of the St Lawrence River. Sage was delighted to find ‘everything on the house’!24 As the conference progressed, he wrote cryptic notes to himself in pencil – essentially lists of daily priorities. He first discussed Overlord with Mountbatten on 11th August, and on the 15th was studying the plans for Overlord and preparing remarks on certain aspects.25 At the same time, he was working on a report on waves and looking into questions about the three possible versions of Habbakuk, such as the wood needed for H[abbakuk] I.
The first official discussion of Overlord took place in a closed session between the American and British COS on 17th August, during which they refined their strategic plans for defeating the Axis forces in Europe. They reported to Churchill and Roosevelt at the first plenary meeting two days later and that afternoon, Bernal was admitted to the inner sanctum for a presentation of Habbakuk by Mountbatten. According to the official record, ‘Professor Bernal demonstrated with the aid of samples of pykrete, the various qualities of this material.’26 The unofficial versions depict scenes of near mayhem, with Churchill’s account being typical:
On receiving permission one of his [Mountbatten’s] staff wheeled in on a large dumb-waiter two blocks of ice about three feet high, one common-or-garden ice, the other Pykrete. He invited the strongest man present to chop each block of ice in half with a special chopper he had brought. All present voted General Arnold into the job of ‘strong man’. He took off his coat, rolled up his sleeves, and swung the chopper, splitting the ordinary ice with one blow. He turned round, smiling, and clasping his hands, seized the chopper again and advanced upon the block of Pykrete. He swung the chopper, and as he brought it down let go with a cry of pain, for the Pykrete had suffered little damage and his elbows had been badly jarred.
Mountbatten then capped matters by drawing a pistol from his pocket to demonstrate the strength of Pykrete against gunfire. He first fired at the ordinary ice, which was shattered. He then fired at the Pykrete, which was so strong that the bullet ricocheted, narrowly missing Portal.
The waiting officers outside, who had been worried enough by the sound of blows and the scream of pain from General Arnold, were horrified at the revolver shots, one of them crying out, ‘My God! They’ve now started shooting.’27
The next day, Bernal attended a meeting on the docks and artificial harbours, and intended to take his first look at the charts of the Normandy coast. While immersing himself in preparations for Overlord he was also being drawn into the operational planning for South-East Asia, by Mount-batten; Sage talked to Wingate several times about the realities of fighting in the jungles. Mountbatten was intent on appointing a senior scientific adviser to his new command and no doubt wanted to retain both Sage and Zuckerman. On the last day of Quadrant, Bernal received a summons to come to the Citadel, where Roosevelt was staying. Churchill wanted a repeat demonstration of the thermal properties of Pykrete.
No one else was there when Professor Bernal was ushered in, followed by a waiter who carried a silver pitcher of boiling water and two large silver punch bowls.
‘Wait till you see this!’ the Prime Minister said excitedly as Bernal placed a small block of ice in one of the bowls and added the water.
‘See!’ smiled Churchill after a few minutes. ‘The ice melted!’
Roosevelt nodded and watched Bernal put a cube of Pykrete in the other punch bowl and pour on some more scalding water.
Churchill waited several minutes, then sat back in his chair and said quite happily, ‘Hasn’t melted at all!’28
No doubt, Sage then explained to the two statesmen that the wood pulp in Pykrete formed a soggy, insulating layer on the surface so that heat was not conducted to the interior of the block.
By the end of Quadrant, the combined Chiefs of Staff rejected Habbakuks I and III, but agreed that a research and development programme for the huge Habbakuk II should move ahead, under the direction of an Anglo-American-Canadian Habbakuk Board, with Dean Mackenzie of the Canadian National Research Council as its head. The COS cabled their deputies in London suggesting that Rivett of COHQ should be involved and that he should come over immediately with Perutz. Bernal and Lieutenant Commander Grant RN from the CCO’s staff were to remain in North America, but should be transferred from Combined Operations to the Admiralty.29 It was soon made clear that Geoffrey Pyke, Habbakuk’s begetter, would not be welcome. Mountbatten sent a telegram to COHQ saying: ‘Dean Mackenzie has just sent me a message to say that it is his considered opinion that if Pyke came out it would have a disastrous effect on American participation in this scheme, and he would have to advise his government accordingly. In the light of this uncompromising attitude, I am afraid Pyke will have to stand down for the good of his own scheme. Consulted Bernal who entirely agrees. We are both so sorry.’30 Just a few days before, Pyke had been elated as word reached COHQ that Habbakuk was being supported at Quadrant, and he was preparing to return to Canada. Now he was devastated and blamed Bernal for hijacking his project.
Although Roosevelt had given his assent to Habbakuk in principle, there were members of his COS, notably Admiral King, Chief of the US Navy, who had grave doubts about its practicality. His reservations were shared by many in the British Admiralty. King ordered his staff to prepare a critical review to be presented to the new Habbakuk Board. Sage travelled down to Washington by train as soon as Quadrant was over, and was staying happily in the ‘negro district’ of Georgetown.31 Jon Rivett had joined him from COHQ and was preparing to go before the Habbakuk Board with Sage. A cable was sent from London to Washington stating that Rivett and Bernal were not qualified to represent the Admiralty’s views.32 Sage seemed to sense the growing hostility to Habbakuk, judging by the letter he wrote to Mountbatten, who had returned to London to organize staff for his new posting to South-East Asia. The letter also indicates that Churchill at Quadrant raised the possibility of a hybrid between his beloved floating piers and Habbakuk:
BRITISH JOINT STAFF MISSION OFFICES OF THE COMBINED CHIEFS OF STAFF WASHINGTON
6th September 1943
MOST SECRET AND PERSONAL
Dear C.C.O. and S.A.C.S.E.A.,
A number of points have arisen since
you left here that may be of interest to you.
We have had very rough weather over the Prime Minister’s Floating Airfields, the Americans much preferring carriers. I am being sent to a Committee of four American Admirals in order to be sunk without a trace.
There does seem to be some point in these airfields, however, if we can make them light enough and readily unpackable from one or two ships. This I am convinced can be done in either of two ways; using the American Naval Pontoon equipment in an expanded form, carrying a light landing platform, or by re-designing larger pontoons and joining them together in a way which has been worked out most ingeniously by Major Steer-Webster. By now Lochner will have seen you and given the details. I think he is well worth listening to and has got something in using ingenuity rather than brute force in dealing with waves.
Whether we have these fields or not would depend almost entirely on your wanting them. That is, if you are finding sheltered harbours or lees of islands where you could use them in your operations [in S. E. Asia]…
As you have seen from my cable and possibly heard from Lochner, I have been somewhat distressed at the prospect of being attached here for the duration on Habbakuk II. I realise quite well it was because it is so hard to find anybody that they put me on to the Committee, but I feel very strongly, especially after the work started in Quebec for OVERLORD and the Far East area, that I would be much more use, once the thing has got started, back in England. I hope you will be able to represent this fairly strongly before you leave, particularly in regard to any plans that you may have for organising a separate technical service in your command.
… I hope that you have been able to provide satisfactorily for Pyke, so that he can be most use to you and to the Habbakuk scheme.