by Andrew Brown
There was another cable waiting for Bernal in Cairo. It was from Mount-batten instructing him to make his way to Canada as soon as possible to oversee the Habbakuk tests that were about to start; enclosed with the cable was a travel permit that gave Sage ‘stratospheric priority’ for his journey. Clearly the CCO had persuaded his fellow Chiefs of Staff to move ahead with the programme that Bernal had outlined in his various reports. Their acquiescence had come despite a demonstration at COHQ by a naval officer, who fired bullets into a large block of ice and a block of Pykrete prepared for the occasion by Perutz.61 The ice duly shattered, but the bullet fired at the block of Pykrete rebounded and hit Sir Alan Brooke in the shoulder, fortunately without causing any injury. Sage was in a quandary – there was an enormous amount of work to be done in North Africa and everyone was relying on him to organize it, yet he could hardly ignore the wishes of the CCO on a project that he knew had Churchill’s support. He put the cable and travel warrant in his pocket and said nothing for the moment.
After five days of briefings in Cairo, it was time for Bernal and Zuckerman to move closer to the front. They took off for Libya, but after an hour in the air had to turn back to Cairo because of engine trouble.62 The engine was repaired and they flew over one thousand miles west following the coastal road that Rommel’s troops had used to flee, three months before. They spent the night at a camp known as Marble Arch, where Sage, in unknown circumstances, lost his pyjamas!63 The next day they flew a further six hundred miles or so west, before landing at the heavily damaged Tripoli airfield of Castel Benito. Rommel had ceded the port of Tripoli two weeks before and only after sinking as many blockships as possible to make the harbour unusable. Prior to that the port had been bombarded for two years, first by the Royal Navy and then by the RAF. Bernal was supposed to assess the extensive damage to ships, docks and harbour and apportion the blame – like an insurance loss adjuster under arms.
Before starting their work, Bernal and Zuckerman established contact with the senior Army and RAF officers, who now controlled Tripoli, and also met the Italian Prefect, who had been encouraged to retain some authority over the civilian population. After a few days, they had won over the military chiefs, one or two of whom had been unimpressed by their arrival in the middle of such chaos: ‘Oh, you’re the two fellows who’ve been sent out to see what’s in a bomb hole’64 was their greeting from the head of the Desert Air Force. Once they had been recognized as making a serious contribution and the initial plans were in place, Sage decided it was time to break the news to Solly about his impending departure. Zuckerman was devastated. In a letter written thirty years later, he admitted to Kendrew that he was ‘terrified to be left to do what I had taken would be his job’.65 In his memoirs, Zuckerman described the ensuing scene:
I spent hours that evening, pleading with him by candlelight – there was no electricity in the hotel – not to go, saying Habbakuk was nonsense, and rattling off a list of his many ideas and projects about which he had got people excited in the past, and where he had reversed his judgement at the last moment… Des became more and more silent as, in desperation, I added accusation to accusation. But all to no avail.66
The next morning, Zuckerman accompanied Sage in their staff car back to Castel Benito and sadly watched him wade through a desert flood to reach the plane that was to return him to Cairo. In the middle of the desert, miles from anywhere, was a small unit from the Royal Signal Corps headed by Capt. Norman Waddleton. Waddleton was a Cambridge physics graduate, who had taken the course in X-ray crystallography taught by Bernal. He was astounded when his old tutor suddenly walked into the encampment, alone, dressed in an ill-fitting RAF uniform.67 No explanation was offered, and Waddleton took the view that Bernal was on a secret mission, so asked no questions. Bernal shared his tent for the night, and the next day Waddleton drove him the remaining miles to Cairo in his jeep.
Back in Cairo, Sage took the opportunity to visit mosques and museums. He found Kendrew, whose mother was a distinguished art historian, to be an amiable companion, and Kendrew for his part was amazed by Sage’s erudition.68 Bernal spent one night by the Nilometer – a stone column standing inside a large cistern that is connected to the river by three tunnels. It was used from the ninth century to measure and predict the annual flood of the Nile, and so to set taxes on that year’s harvest – a perfect example for the Marxist view of science and society. He flew out from Cairo under a full moon, headed for the Gold Coast. Before leaving, he scrawled a hurried and apologetic letter to Zuckerman to wish him luck. He gave him names of some new contacts he had made, including Army experts on the clearing of minefields and a Paramount studio cameraman who had ‘good ideas for better use of cine cameras’. He also told Zuckerman that Kendrew was now in charge of OR for the RAF in the Middle East, and that he was ‘more and more impressed with his ability’.69
The only accommodation Sage could find on his arrival in Accra was a stable, which he shared with a shipwrecked sailor.70 He made friends with a local boy, who asked him if he was American. Sage said ‘No’ to which the boy responded ‘Then you are British like me.’ This spontaneous, friendly remark caused Bernal to reflect on how deep the imprint of colonization was – in the boy’s eyes, they were equal subjects of the British Empire. There were some American airmen in town, and after showing them his travel warrant, Bernal was able to hitch a ride on their ‘inferior plane’. They flew to Ascension Island, a barren mountain covered with volcanic lava in the mid-Atlantic, just south of the equator. The Americans had built an airbase there the previous summer, as a staging post for flights to North Africa and as a base from which bombers could hunt U-boats. They stopped just long enough to eat a meal and to refuel before setting off, but within a short time they had turned back because of engine failure. This time there was no quick repair and Sage found himself marooned. He persuaded the American pilot to explore the island with him on foot. They found a beautiful white-sand beach and took the ‘best bathe ever’. Only afterwards did Sage learn that no one swims there because of sharks. He saw the sharks, but reasoned that they did not see him; he also saw some of the indigenous giant turtles and learned that they formed the chief ingredient for the soup traditionally served at the Lord Mayor of London’s banquet.71 His afternoon was crowned by meeting the District Nurse, who invited him to tea.
Back at the airbase, he found that the Americans had ‘no gas and more whiskey than water’. He attempted to board the first plane out, but was thrown off by a senior American officer and lost his travel permit. After about a week, he managed to get a ride on a Canadian plane, which took him to Recife on the Brazilian coast. From there, they set off for Trinidad, but had to make a forced landing in the forest of Guyana, where he spent a sober night in torrential rain. When they arrived in Trinidad, he made the mistake of taking the pilot to a cricket match and only just avoided being thrown off the plane as a consequence. The next leg of the journey involved flying ‘over the track of Columbus to Nassau and Miami’.72 He arrived in New York on 28th February to find a patriotic parade taking place, with drum majoresses marching in sub-zero temperatures. He had lunch with Hermann Mark and then toured Brooklyn Polytechnic, reunited with Fan.
Geoffrey Pyke had also arrived in New York, and the next day he and Bernal flew up to Ottawa, where they had meetings with Dean Mackenzie and the staff of the National Research Council of Canada. They then took a train west to Saskatoon; it might have been spring in Cairo a month earlier, in Saskatoon the thermometer showed minus 30°C (–228F).73 They found a team of engineers and scientists at work on problems such as the rate of freezing of Pykrete, bonding together of blocks, and the use of steel beams as reinforcement. A major issue was emerging over the plastic flow of ice – evident in glaciers under the effect of gravity. Perutz in London was also studying this phenomenon and came to the conclusion that a large ice-ship would sag under its own weight amidships. He believed that ‘a ship of pykrete would sag more slowly [than pure ice], but not slowly enoug
h, unless it were to be cooled to a temperature as low as 48F’.74
Bernal and Pyke now journeyed to the Canadian Rockies, which, although still cold, were more temperate that Saskatoon. In Jasper National Park, a large-scale model was being built to examine techniques of insulation and refrigeration and to see how it would stand up to ballistics tests and explosives. Sage was as excited by the explosions in the ice as he was to walk past moose and bears. Their final destination was the stunningly beautiful Lake Louise, surrounded by mountains, where they studied the deformation of large steel beams and the construction of large ice blocks; there were more explosions. On the 13th March Bernal sent a generally optimistic progress report75 to COHQ, which concluded: ‘The general view is that the construction of the vessel as such will not offer any particular difficulties.’ He informed London that the Canadians were building a 1,000 ton model, which they expected to complete in fourteen days with the labour of just eight men. The CCO responded with a cable on 21st March saying that the Prime Minister had invited the Chiefs of Staff Committee to arrange for an order to be placed for one complete ship at once with the highest priority, and for further ships without delay if it appeared the scheme was certain of success. Churchill also wanted Pyke and Bernal to go and tell him the whole story, when they returned to England.76
This was perhaps the high-water mark for Operation Habbakuk. The Canadians were confident about constructing a vessel for 1944: the necessary materials were readily available to them (300,000 tons wood pulp, 25,000 tons fibre-board insulation, 35,000 tons timber and 10,000 tons steel). The estimated cost was £700,000. Now that the order had come to move ahead, the project was subjected to wider scrutiny. An Admiralty committee headed by the Chief of Naval Construction sent a critical memorandum to the CCO, who passed their reservations onto Pyke. This led to a return cable labelled ‘HUSH MOST SECRET. CIRCULATION RESTRICTED TO CHIEF OF COMBINED OPERATIONS ONLY.’ The cable read: ‘CHIEF OF NAVAL CONSTRUCTION IS AN OLD WOMAN. SIGNED PYKE.’77 The message was much too funny for the CCO to keep it hushed, and it quickly reached the ears of the Admiral himself, who was furious.
Perutz and his Smithfield Market team kept testing different mixtures of ice and pulp, before deciding that 14% pulp: 86% water gave the best structural properties. Although Perutz rarely left the cold store for meetings at COHQ, he recognized the daunting pitfalls that Operation Habbakuk needed to avoid, and also the time constraints, given that even Canadian winters do not last for ever. He wrote to Pyke in early April pointing out that if certain tests were not completed in May, there would be no chance of delivering a berg ship in 1944. He also expressed some frustration with Bernal, who evidently had suggested that alternatives to wood pulp such as cotton, straw and sawdust might be tried.78
By May the problem of plastic flow or creep, first identified by Perutz, was becoming more serious. Bernal sent back a series of technical reports giving details of the Canadian research findings. The need to use more steel reinforcement, combined with a more effective insulating skin around the vessel’s hull, as well as more elaborate refrigeration soon led to a revised cost estimate of two-and-a-half million pounds. Gloomier news followed in a cable from Bernal and Pyke to the CCO informing him that the Canadians had decided it was impractical to attempt the project ‘this coming season’.79 Despite ‘tactful pressure’ from them, there had been a marked lack of quantitative investigations. The Canadians were not conscious of the urgent strategic need for Habbakuk and therefore displayed a natural reluctance to use unusual methods and to depart widely from customary procedures. In short, whereas Bernal had persuaded those at COHQ that the vital need was to press ahead with Habbakuk and be prepared to abandon the scheme if it ran into insurmountable obstacles, the Canadians were not willing to accept a greater risk of failure than would be usual in a large commercial engineering project. In these circumstances, Bernal and Pyke had both come to the conclusion that no Habbakuk vessel would be ready in 1944.
Sage was now back in New York where he took a few days to visit his cousin Persis and other old friends. It was time for him to return to London and again it was a question of a makeshift flight with considerable hazard. He crossed the North Atlantic in an unheated bomb bay shared with Alexander Korda, the film director.80 After a ‘nightmare journey’ he was relieved to see the dawn over Ireland on 16th May. The following week the Evening Standard, which in early February had announced Bernal’s arrival in North Africa, ran a small news item under the heading ‘Sealed Lips’.81 No doubt fed by the COHQ publicity department, the newspaper informed its readers that Professor Bernal ‘who is a scientific adviser to Lord Louis Mountbatten has returned to this country. The task which took him to North Africa and North America is secret.’ Sage was quoted as saying, ‘I wish I could tell you, but I can’t.’
12
Overlord
The headquarters of Combined Operations (COHQ) occupied what was formerly the town house of the Dukes of Buccleuch, in Richmond Terrace. One of the more volatile and cantankerous characters in residence during 1942–3 was Evelyn Waugh, the novelist. He was there as Liaison Officer representing the Special Service Brigade, until he was forced out by his senior officers for constantly causing trouble. He was often drunk. The week after Bernal returned from his travels, Waugh arrived for lunch with Mountbatten ‘rather tipsy’ and ‘found the house a nest of Communists’,1 suggesting that Sage was back at work. Habbakuk remained the highest priority for Bernal, although the Canadians were not pressing ahead with a large-scale model and there seemed no prospect of an operational berg ship until 1945. A meeting was held at COHQ to review the situation at the end of May; Bernal stated that he still believed a berg ship was feasible and that Pykrete was the best material to use. Perutz indicated that 1.7 million tons of Pykrete in block form would need to be produced during the next Canadian winter to construct one berg ship ready for use in 1945.2
When Churchill appointed Mountbatten as Chief of Combined Operations in November 1941, he emphasized that COHQ was to think offensively, and that its primary object would be to prepare for the great invasion of the Continent. It was natural, therefore, that the CCO should be a member of the Combined Commanders, a group of senior officers assembled in May 1942, to plan the invasion. From the first, Mountbatten favoured a landing on the wide beaches of Normandy, rather than the closer, but more heavily defended, Pas de Calais. In discussions at COHQ, it was pointed out to Mountbatten by Hughes-Hallett, his naval adviser, that if the landing was going to take place on relatively undefended beaches, the invading force would have to bring harbours with them to provide protection from rough seas and to allow mechanized equipment and heavy supplies to be offloaded.3 Soon after the first meeting of the Combined Commanders, Mountbatten sent the Prime Minister a minute on ‘Piers for use on beaches’. This considered the relative merits of piers constructed from scaffolding versus pontoon piers. Churchill wrote a reply on the bottom of his copy, dated 31st May 1942, addressed to the CCO or deputy: ‘They must float up and down with the tide… Let me have the best solution worked out. Don’t argue the matter. The difficulties will argue for themselves.’4 A prototype, the Spud Pontoon Pier, had already been designed in the Transportation Department of the War Office. At Combined Operations, Captain Tom Hussey, to whom Bernal reported, was the head of a committee that had been looking into ‘certain alternatives for forming sheltered anchorages by means of blockships’5 since 1941. Bernal’s diary in October 1942 showed that work on blockships (old vessels sunk to form breakwaters) was his second priority to Habbakuk.
Uncoordinated work on providing artificial harbours continued at both the Admiralty and the War Office, but in March 1943 Churchill reminded Mountbatten of the lack of real progress with the floating piers: ‘Dilatory experiments with varying types and patterns have resulted in our having nothing… I was hoping to reduce the strain on landing-craft by the rapid building of these piers. I am very much disappointed.’6 Churchill arranged that an engineer from the War Office
, Major Steer-Webster, would report to him frequently on the latest developments, and in May rebuked the Chiefs of Staff for their lack of attention to the problem. They responded by calling on Steer-Webster to give his opinion about the rival schemes. He felt confident in his answers to such senior officers because he had already checked his ‘mathematics and engineering principles’ with many experts, including Cherwell and Bernal.7 In his opinion, the best option was the one from the War Office, which involved the construction of huge concrete caissons or cubes that would be towed across the Channel and form the floating inner harbour wall. These caissons, known as Phoenixes, would have a flexible steel roadway – a Whale – laid over the top of them. The whole became known as a Mulberry harbour. Steer-Webster built scale models and relied heavily on guidance given to him by Sage on wave formation. In later years, he told Bernal that ‘but for your practical and theoretical advice there would have been no Mulberry harbours’.8