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. 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: 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. The research took place in a refrigerated meat locker behind a protective screen of frozen animal carcasses.
Scale model The decision was made to build a large-scale model at
Jasper National Park in Canada to examine insulation and refrigeration techniques, and to see how pykrete would stand up to artillery and explosives. Large ice blocks were constructed at
Lake Louise, Alberta, and a small prototype was constructed at
Patricia Lake, Alberta, measuring 60 by 30 feet (18 metres by 9 metres), weighing 1,000 tons and kept frozen by a one-horsepower motor. Bernal informed COHQ that the Canadians were building a 1,000-ton model, and that it was expected to take eight men fourteen days to build it. The Chief of Combined Operations (CCO) responded that Churchill 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 that further ships were to be ordered immediately if it appeared that the scheme was certain of success. The Canadians were confident about constructing a vessel for 1944. The necessary materials were available to them in the form of 300,000 tons of wood pulp, 25,000 tons of
fibreboard insulation, 35,000 tons of timber and 10,000 tons of steel. The cost was estimated at £700,000.
Naval architects and engineers continued to work on Habakkuk with Bernal and Perutz during the summer of 1943. The requirements for the vessel became more demanding: it had to have a range of and be able to withstand the largest waves recorded, and the Admiralty wanted it to be torpedo-proof, which meant that the hull had to be at least thick. The
Fleet Air Arm decided that heavy bombers should be able to take off from it, which meant that the deck had to be long. Steering also raised problems; it was initially projected that the ship would be steered by varying the speed of the motors on either side, but the Royal Navy decided that a rudder was essential. However, the problem of mounting and controlling a rudder over high was never solved. • Habakkuk III was a smaller, faster version of Habakkuk II. File:Habakukk aircraft 02.jpg|Aircraft carrier drawings. File:Habakukk aircraft 03.jpg|Cross section, showing 40 ft (12 m) thick walls made of
pykrete Air Chief Marshal Portal asked about potential bomb damage to Habakkuk III, and Bernal suggested that a certain amount of deck covering might be ripped off, but could be repaired by some kind of flexible matting. It would be more difficult to deal with bomb holes in the centre portion, though the roof over the aircraft hangars would be made blast proof against 1,000 kg bombs. Bernal considered that no one could say whether the larger Habakkuk II was a practical proposition until a large-scale model could be completed and tested in Canada in the spring of 1944. He had no doubts about the suitability of pykrete as a material, but said that constructional and navigational difficulties remained to be overcome. The final design of Habakkuk II gave the
bergship, as it was called, a displacement of 2.2 million tons. Steam turbogenerators were to supply for 26 electric motors mounted in separate external
nacelles (normal, internal ship engines would have generated too much heat for an ice craft). Its armament would have included 40 dual-barrelled 4.5" DP (dual-purpose) turrets and numerous light
anti-aircraft guns, and it would have housed an airstrip and up to 150 twin-engined bombers or fighters. == Shooting incident ==