World War II was a breeding ground for absurdly extravagant ideas. With the German navy dominating the Atlantic thanks to its submarines, the Allies began to wonder how to take control of the seas. That led to one of history’s most harebrained projects: the development of Habbakuk, an aircraft carrier more than 600 meters long, built from ice and wood pulp.
Transporting troops and supplies across the Atlantic was the cheapest way for the United States to support its allies in Europe. But despite the efforts of Alan Turing and his colleagues, German submarines turned that into a game of Russian roulette. So the war planners decided to create a series of ships that would be practically immune to enemy torpedoes, and they had to be cheap and quick to build. It was in this context that the Habbakuk Project, an ice aircraft carrier, was born in England.
The father of the idea was Geoffrey Pyke, a man of extravagant, disheveled appearance but an absolutely brilliant mind. He went through life without socks, with the look of someone who hadn’t shaved or bathed in days, with unkempt hair and wrinkled clothes. However, he had made a name for himself during World War I by carrying out one of the most famous escapes from Ruhleben prison. Using his wits, he calculated the times of day when the sun made it difficult for the guards to see every point of the camp and devised a successful escape plan. Before that, he had stood out as a pedagogue, merchant, spy and inventor.
All his inventions were unconventional. He is considered one of the precursors of radar, having developed a system of microphones carried in hot-air balloons that were used to triangulate the position of enemy aircraft. Although his name is practically unknown, Geoffrey Pyke was also responsible for Project Plough, a small transport ideal for traveling over snow that the Americans turned into the famous M29, better known as “The Weasel.” When Churchill learned that Pyke was proposing to build a ship of ice, even though the idea sounded strange—to say the least—he believed it might become the weapon they were looking for to end the reign of the German submarines.
That is how Pyke got “carte blanche” to begin the research. He carried out his first tests in secret, inside the meat cold-storage room of a London market, the Smithfield Meat Market, which had an enormous refrigerator with enough space for his experiments. He also hired two renowned scientists to help him obtain ice blocks that were as strong as possible. The first was Max Ferdinand Perutz, the same molecular biologist who would receive the Nobel Prize in Chemistry in 1962. The other was Herman F. Mark, who would later become the father of polymers.
The first challenge they had to face was modifying the properties of ordinary ice to make it a much stronger material and, above all, one that would not melt quickly. It was also desirable for it to be easy to repair when damaged by enemy fire.
The solution they found was to mix ice with wood pulp. Both materials were abundant and cheap, and together they had a hardness that could compete with concrete. After a few trials, they had an extremely simple and strong material, which they named “pykrete,” after Geoffrey’s surname and “concrete,” the English translation of “hormigón.” The strength of this material was incredible: concrete’s breaking point is about 21 megapascals, while pykrete’s varied—depending on its composition—between 15 and 25 megapascals. The ice ship would be as strong as if it were made of concrete.
Buoyancy had yet to be solved. Even though ice floats in water, Perutz knew that the slow flow of ice—a phenomenon known as “plastic flow”—could cause the ship to gradually sink. To avoid it, the ice temperature had to be kept around -16°C. It was necessary to insulate the ship’s surface and fit it with an adequate refrigeration system. Of course, a whole network of pipes had to be laid inside the ice to distribute the cold throughout the ship.
What had begun as a very simple project was gradually becoming more complicated. Yet Pyke remained optimistic and was convinced these difficulties would be solved as the project advanced. The pykrete was presented to the heads of state, admirals and prime ministers of the Allied forces, who approved a considerable amount of funds for the construction of a small-scale prototype.
This prototype began to be built in Canada, far from prying enemy eyes. The chosen site was Lake Patricia, located in a remote area of Jasper National Park. The ship would measure 18 meters long, 9 meters wide, and weigh a little over one million kilograms. The 1,000 tons of pykrete were kept refrigerated by a cooling unit driven by a small one-horsepower motor. An iron frame was built, and on it the improved pykrete blocks were assembled. Perutz had modified the material, discovering that the ideal composition contained 14% wood pulp and 86% water. The Canadian workers, who had little idea what they were building, nicknamed the project Noah’s Ark.
Even though the plastic flow problem had not been definitively solved, Pyke was euphoric when he saw the finished prototype. He had proven the project’s feasibility, and they could begin building the final model. However, the need for a steel frame and other unforeseen costs increased the budget, forcing the United Kingdom to ask the United States for funds. The Americans put a single condition on the money: Geoffrey Pyke had to leave the project. That is how the mastermind behind Project Habbakuk found himself removed from it, lost his sanity, and committed suicide shortly afterward.
The full-scale Habbakuk
In August 1943, the chiefs of staff met to discuss Habbakuk’s characteristics. It was intended to have a range of 11,000 km, withstand any storm, and be proof against torpedoes. This required a hull at least 12 meters thick. Enthusiastic, the admirals decided it should be able to carry a complete air fleet of bombers, and that they should be able to take off and land on it. It would be an aircraft carrier, with a runway more than 600 meters long. At this point it was already referred to as “Habbakuk II.” The monster was to be armed, so 40 dual 4.5-inch guns, combat turrets, and “some dozens of anti-aircraft guns” were requested. Moving such a giant would not be easy, so it was decided to equip it with steam turbogenerators with a power of 33,000 horsepower, which would supply the energy for the 26 electric motors that would turn the propellers.
But late in 1943, Portugal finally authorized the Allies to use the airfields of the Azores, which allowed Allied aircraft to hunt down the dreaded Nazi submarines more efficiently. Suddenly, crossing the Atlantic was no longer so dangerous. This fact, together with growing criticism from senior officials such as Sir Charles Goodeve, made the project begin to “take on water.” Goodeve was right about some of the objections. It was paradoxical that a ship made of ice to cut costs and replace scarce, expensive steel needed kilometers of steel pipes to keep it cold. When the high command learned that the Manhattan Project was almost finished and that the “nuclear bomb” was possible, Habbakuk definitively went down.
The “Habbakuk Development Board” met for the last time in December 1943, and reached the following conclusion: “The great Habbakuk II of pykrete has proved impractical due to the enormous amount of resources required, added to the enormous technical difficulties it entails.” The abandoned prototype on Lake Patricia floated, intact, for a whole year before melting. Its skeleton remains at the bottom of the lake, where a team of divers managed to photograph it a few years ago. Those remains and pykrete—a material that still has not found a practical use—are all that is left of one of the most extravagant projects of World War II.
Seen at Dark Roasted Blend
