Project Habakkuk or Habbakuk (spelling varies) was a plan by the British during the Second World War to construct an aircraft carrier out of pykrete, a mixture of wood pulp and ice, for use against German U-boats in the mid-Atlantic, which were beyond the flight range of land-based planes at that time. The plan was to create what would have been the largest ship ever at 600 metres (1,969 ft) long, which would have been much bigger than even the USS Enterprise and the USS Gerald R. Ford, the largest naval vessel ever, at 342 metres (1,122 ft) long. The idea came from Geoffrey Pyke, who worked for Combined Operations Headquarters. After promising scale tests and the creation of a prototype on Patricia Lake, Jasper National Park, in Alberta, Canada, the project was shelved due to rising costs, added requirements, and the availability of longer-range aircraft and escort carriers which closed the Mid-Atlantic gap that the project was intended to address.
History
Initial concept Geoffrey Pyke was an old friend of J. D. Bernal and had been recommended to Lord Louis Mountbatten, Chief of Combined Operations, by the cabinet minister Leopold Amery. Pyke worked at Combined Operations Headquarters (COHQ) alongside Bernal and was regarded as a genius by Mountbatten. Pyke conceived the idea of Habakkuk while he was in the United States organising the production of M29 Weasels for Project Plough, a scheme to assemble an elite unit for winter operations in Norway, Romania and the Italian Alps. He had been considering the problem of how to protect seaborne landings and Atlantic convoys out of reach of aircraft cover. The problem was that steel and aluminium were in short supply, and were required for other purposes. Pyke decided that the answer was ice, which could be manufactured for just 1% of the energy needed to make an equivalent mass of steel. He proposed that an iceberg, natural or artificial, be levelled to provide a runway and hollowed out to shelter aircraft. From New York, Pyke sent the proposal via diplomatic bag to COHQ, with a label forbidding anyone apart from Mountbatten from opening the package. Mountbatten in turn passed Pyke's proposal on to Churchill, who was enthusiastic about it. Pyke was not the first to suggest a floating mid-ocean stopping point for aircraft, nor even the first to suggest that such a floating island could be made of ice. A German scientist, A. Gerke from Waldenburg, had proposed the idea and carried out some preliminary experiments on Lake Zurich in 1930. The idea was a recurring one: in 1940 an idea for an ice island was circulated around the Admiralty, but was treated as a joke by officers, including Nevil Shute, who circulated a memorandum that gathered ever more caustic comments. The document was retrieved just before it reached the First Sea Lord's inbox.
Code name and spelling The project's code name was often incorrectly spelled Habbakuk in official documents. This may have been Pyke's error. At least one early unsigned document (apparently written by him) spells it Habbakuk. However, post-war publications by people concerned with the project, such as Perutz and Goodeve, all restore the proper spelling, with one "b" and three "k"s. The name is a reference to the project's ambitious goal: Behold ye among the heathen, and regard, and wonder marvellously: for I will work a work in your days, which ye will not believe, though it be told you. Habakkuk 1:5 David Lampe, in his book, Pyke, the Unknown Genius, states that the name was derived from Voltaire's Candide and was misspelled by Pyke's Canadian secretary. However, the word does not actually appear in Candide, so this is probably inaccurate.
Pykrete
In early 1942 Pyke and Bernal called in Max Perutz to determine whether an icefloe large enough to withstand Atlantic conditions could be built up fast enough. Perutz pointed out that natural icebergs have too small a surface above water for an airstrip, and are prone to suddenly rolling over. The project would have been abandoned if it had not been for the invention of pykrete, a mixture of water and woodpulp that when frozen was stronger than plain ice, was slower-melting and would not sink. Developed by his government group and named after Pyke, it has been suggested that Pyke was inspired by Inuit sleds reinforced with moss. This is probably apocryphal, as the material was originally described in a paper by Mark and Hohenstein in Brooklyn. Pykrete could be machined like wood and cast into shapes like metal, and when immersed in water formed an insulating shell of wet wood pulp on its surface that protected its interior from further melting. However, Perutz found a problem: ice flows slowly, in what is known as plastic flow, and his tests showed that a pykrete ship would slowly sag unless it was cooled to −16 °C (3 °F). To accomplish this the ship's surface would have to be protected by insulation, and it would need a refrigeration plant and a complicated system of ducts. Perutz proceeded to conduct experiments on the viability of pykrete and its optimum composition in a secret location underneath Smithfield Meat Market in the City of London. The research took place in a refrigerated meat locker behind a protective screen of frozen animal carcasses.
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