Project Habakkuk

Project Habakkuk or Habbakuk (spelling varies; see below) was a plan by the British in World War II 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 was out of range of land-based planes.

History

Pyke conceived the idea of Habbakuk while in the US 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.^[1] 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 required for other purposes. Pyke realized that the answer was ice, which could be manufactured for only 1% of the energy needed to make an equivalent mass of steel and 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 he had composed on Habbakuk via diplomatic bag to COHQ with a label forbidding anyone apart from Mountbatten from opening the package. Mountbatten in turn told Churchill about Pyke's proposal, who was enthusiastic about it.^[2]

Pyke and Bernal now called in Max Perutz to determine whether an ice floe large enough to withstand Atlantic conditions could be built up fast enough. He 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, except for the invention of Pykrete, a mixture of sea water and woodpulp which frozen together was tougher than steel and would neither melt nor sink. Pyke was reportedly inspired by Inuit sleds reinforced with moss.^[1]

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 which protected its interior from further melting. However, Perutz found a problem: ice slowly flows, 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 (3.2 °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.^[2]

Experiments on the viability of Pykrete and the optimum composition of it were conducted by Perutz in a secret location underneath Smithfield Meat Market in the City of London.^[3]^[4] The experiments were carried out by Perutz and his collaborators in a refrigerated meat locker in a Smithfield Market butcher's basement, behind a protective screen of frozen animal carcasses.^[5]

A demonstration of Pykrete was given at Combined Operations Headquarters (COHQ) by a naval officer, who fired bullets into a large block of ice and a block of Pykrete prepared by Perutz. The ice shattered, but the bullet fired at the Pykrete rebounded and hit Sir Alan Brooke in the shoulder, fortunately without causing any injury.^[6]

The decision was made to built a large scale model in Jasper National Park in Canada to examine insulation and refrigeration techniques and to see how it would stand up to artillery and explosives, while at Lake Louise, Alberta large ice blocks were constructed, and a small prototype was constructed at Patricia Lake, Alberta, measuring only 60 feet by 30 feet (18 by 9 m), weighing in at 1,000 tons and kept frozen by a one-horsepower motor.^[5]. Bernal informed COHQ that the Canadians were building a 1,000 ton model, and that it was expected to take 8 men 14 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, with further ships to be ordered immediately if it appeared 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.^[6]

Meanwhile, Perutz had determined via his experiments at Smithfield Market that the optimum structural properties were given by a mixture of 14% wood pulp and 86% water. He wrote to Pyke in early April 1943 and pointed out that if certain tests were not completed in May, there would be no chance of delivering a completed ship in 1944.

By May the problem of plastic flow had become serious and it was obvious that more steel reinforcement would be needed as well as a more effective insulating skin around the vessel's hull. This caused the cost estimate to increase to £2.5 million. In addition, the Canadians had decided that it was impractical to attempt the project "this coming season", and Bernal and Pyke were forced to conclude that no Habbakuk vessel would be ready in 1944.^[6]

Pyke had been excluded from participating in the planning for Habbakuk as it was considered that he could have a disastrous effect on American participation, and Bernal agreed with this decision, which was caused in main by Pyke's disagreements with American personnel which had caused his removal from Project Plough.^[7]

In the early summer of 1943, naval architects and engineers continued to work on Habbakuk with Bernal and Perutz. The requirements for the vessel became more demanding; it had to have a range of 7,000 miles and be able to withstand the largest waves recorded, while the Admiralty wanted it to be torpedo-proof, which meant that the hull had to be at least 40 ft thick. The Fleet Air Arm for their part decided that heavy bombers should be able to take off from it, which meant that the deck had to be 2,000 ft long. Steering also raised problems; it was initially projected that the ship 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 100 ft high was never solved.^[6]

Naval architects had produced three alternative versions of Pyke's original concept, which were discussed at a meeting with the Chiefs of Staff in August 1943:

Air Chief Marshal Portal asked about potential bomb damage to Habbakuk 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 hangers would be made proof against 1,000 kg bombs. Bernal considered that no one could say whether the larger Habbakuk 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.^[6]

The final design of Habbakuk II gave the bergship (as it was referred to) a displacement of 2.2 million tons. Steam turbogenerators were to supply 33,000 hp to supply 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.^[2]

At the Quebec Conference of 1943 Lord Mountbatten brought a block of Pykrete along to demonstrate its potential to the bevy of admirals and generals who had come along with Winston Churchill and Franklin D. Roosevelt. Mountbatten entered the project meeting with two blocks and placed them on the ground. One was a normal ice block and the other was Pykrete. He then drew his service pistol and shot at the first block. It shattered and splintered. Next, he fired at the Pykrete to give an idea of the resistance of that kind of ice to projectiles. The bullet ricocheted off the block, grazing the trouser leg of Admiral Ernest King and ended up in the wall. The Admiral was impressed by Mountbatten's unorthodox demonstration.^{citation needed}

Later that year Habbakuk began to lose priority. Mountbatten listed several reasons:

In addition, Mountbatten himself had withdrawn from the project. The final Habbakuk Board meeting took place in December 1943 and it was announced that "The large Habbakuk II made of Pykrete has been found to be impractical because of the enormous production resources required and technical difficulties involved".

The use of ice had actually been falling out of favour before that, with other ideas for "floating islands" being considered, such as welding Liberty Ships or landing craft together (Project TENTACLE).^[8] It took three hot summers to completely melt the prototype constructed in Canada.

Criticism

The Habakkuk design received criticism, notably from Sir Charles Goodeve, Assistant Controller of Research and Development for the Admiralty during World War II.^[9] In an article published after the war Goodeve pointed out the large amount of wood pulp that would be required, enough to affect paper production significantly. He also claimed that each ship would require 40,000 tons of cork insulation, thousands of miles of steel tubing for brine circulation, and four power stations, but that for all those resources (some of which could be used to manufacture conventional ships of more effective fighting power) Habakkuk would only be capable of six knots of speed. Much of his article also contained extensive derisive comments about the properties of ice as used for ship construction.

Spelling

The project's code name seems to have been consistently (mis-)spelled Habbakuk in the Admiralty and Government documents at the time. This may in fact have been Pyke's own error, as at least one early document apparently written by him (though unsigned) spells it that way. (However, post-war publications by people concerned with the project, e.g. Perutz and Goodeve, all restore the proper (one 'B' and three 'K's) spelling.) The name is a biblical reference to the project's ambitious goal: "...be utterly amazed, for I am going to do something in your days that you would not believe, even if you were told." (Habakkuk 1:5, NIV)

David Lampe in his book, Pyke, the Unknown Genius, states that the name was derived from Voltaire's Candide and was mispelt by his Canadian secretary. The name stuck and was never corrected. The reference to Bible appears to have come after the war when journalists were told about part of the project and they connected the Biblical text with the name.

Cultural references

Notes

^ ^a ^b ^c Swann, Brenda; Francis Aprahamian (1999). J.D. Bernal: A Life in Science and Politics. Verso. ISBN 1859848540.
^ ^a ^b ^c Perutz, Max F. (2002). I Wish I'd Made You Angry Earlier: Essays on Science, Scientists, and Humanity. Oxford University Press, pp. 86-87. ISBN 019859027X.
^ Gratzer, Walter (2002-03-05). "Max Perutz (1914–2002)". Current Biology 12 (5): R152–R154. doi:10.1016/S0960-9822(02)00727-3. Retrieved on 2008-01-12.
^ Ramaseshan, S (2002-03-10). "Max Perutz (1914–2002)". Current Science 82: 586–590. Indian Academy of Sciences. ISSN 0011-3891. Retrieved on 2008-01-12.
^ ^a ^b Collins, Paul (2002). "The Floating Island". Cabinet Magazine (7). Retrieved on 2008-01-12.
^ ^a ^b ^c ^d ^e Brown, Andrew (2005). J.D. Bernal: The Sage of Science. Oxford University Press. ISBN 0198515448.
^ Adelman, Robert H.; George Walton (2004). The Devil's Brigade. Naval Institute Press. ISBN 1591140048.
^ National Archives docket PREM 3/216/4 -- Adm. Noble's reports on Habakkuk/Tentacle
^ Sir Charles Goodeve (April 19, 1951). "The Ice Ship Fiasco". London Evening Standard.
^ IGN profile
^ TotalPlaystation profile
^ Byrne, Eugene (May 2000), Interzone(155)

Contents

History

Criticism

Spelling

Cultural references

Notes

Further reading

External links