Geoffrey Pyke, better known for his ambitious proposals for a kind of floating mid-Atlantic airbase constructed of ice. His idea was first promoted in 1942 as an ice aircraft carrier, and magazines featured pictures of a conventional aircraft carrier of a translucent, glistening appearance looming like a ghost out of the mist. Pyke’s idea was rather different – it was for a floating raft to act as a fuel base. The concept was developed starting as Project Habakkuk, from the biblical text that includes the words: ‘Be utterly amazed, for I am going to do something in your days that you would not believe, even if you were told.’ Pyke consistently misspelt it Habbakuk, and that is how it is usually recorded. The idea was for the construction of a vast floating airbase made with a mixture of wood pulp and ice. The compound substance was slower to melt and more bullet-resistant than ice alone, and was named Pykrete. But in fact, although his name is forever associated with this grand design, neither the concept nor the substance were really Pyke’s. The first proposal for an ice airbase actually came from a German engineer, Dr Gerk, and was reported in 1932.
Gerk’s proposals from that time look very like the later magazine illustrations that Geoffrey Pyke promoted. What is more, Pyke was not even the inventor of what became known as Pykrete. The secret story behind this curious idea began when Pyke was shown a paper written, many years earlier, by Professor Herman Mark in Austria. Mark was a former professor of physical chemistry at the University of Vienna and an expert on the structure of plastic materials. For many years he studied X-ray diffraction, a technique in which the effect of a material on a beam of X-rays can be used to work out the molecular structure that lay hidden within the material. In 1926 he joined the chemical company IG Farben and worked on the development plastics that we now take for granted – PVC, polystyrene, polyvinyl alcohol and synthetic rubber.
Mark laid plans to leave Germany as Hitler was preparing for war. He had a huge store of platinum wire that he wished to take with him because it is a catalyst that is crucially important for his research. He knew the authorities would not permit him to remove such an important element from Germany, so Mark conceived a way of smuggling the wire with him. He bent the platinum wire into the shape of coat hangers, and his wife knitted neat covers for them all. When his suitcases were checked for contraband, the coat hangers did not even attract a second glance. The Canadian International Pulp and Paper Company in Dresden had asked Mark to come and organize research at their research headquarters in Canada, but the Gestapo arrested him, confiscated his passport, and gave him an official order not to contact any Jews. By bribing an official with a payment equal to his annual salary he secretly retrieved his passport, and – with the help of the paper company – he managed to obtain a visa to enter Canada. In April 1938 he mounted a Nazi pennant on the front of the family car, tied their skis to the roof of the vehicle, and drove across the frontier to Zurich, Switzerland, with the clothes (on their coat hangers) safely concealed in suitcases. From here they set off to reach London, England, where Mark boarded a transatlantic vessel to sail to Montreal.
He ended up carrying out research on paper pulp not in Canada, but in the United States at the Brooklyn Polytechnic where he set up the first course in the world for students of polymers and plastics. Mark was convinced that there was an important future for composite materials made from fibres held together in a mass by a plastic bonding agent. He was right, of course; the new Boeing Dreamliner is largely constructed from just such composite plastic materials. One of Mark’s early trials was an investigation of a wood pulp composite that was bonded, not with plastic, but with ice. The resulting material had properties rather like present-day fibreglass and was very strong.
In 1942, Mark sent a paper on his research to one of his former students, Max Perutz, who had escaped from Germany to England. Perutz is the scientist who coined the term ‘molecular biology’. I knew him later at Cambridge. When Perutz passed the papers to Geoffrey Pyke, it was Mark’s research on which Pyke set out to base his proposals for a floating mid-Atlantic airfield. His plan was for a top-secret ‘aircraft carrier’ made of ice and pulp that floated in the middle of the Atlantic; it would allow planes to stop and refuel, thus bringing Europe within easy flying distance of the United States. But would it work? Several practical trials were carried out in the summer of 1943, and a small prototype was constructed at Patricia Lake, Alberta, Canada. It measured 60ft (18m) by 30ft (9m) and was thought to weigh 1,000 tons. A 1hp (0.75kW) engine drove the freezer unit to keep the ice solid. Pyke himself was not permitted to join these trials, as he had already caused problems when the Weasel idea was being investigated in America, but he remained a persistent advocate of the concept.
Pykrete proved to be a solid material; buoyant, slow to melt, low in density and floating high in the water. In recent years television documentary producers have recreated Pykrete and there is no doubt that it works. But Pyke was not easy to work with, the scaling-up of the project would have cost prodigious amounts of money, and the sheer size of the project meant it was never tried on a larger scale. As a result, Pyke’s private experiments continued and he is, to this day, firmly associated with the strange saga of the aircraft carrier to be made of ice; but both the concept, and the material, had already been published years before. The secret origin of Pykrete was nothing to do with Pyke, and Professor Mark surely deserves his own place in the history of World War II.