Vince Houghton - Nuking the Moon - And Other Intelligence Schemes and Military Plots Left on the Drawing Board

Yep. That’s the science.

Pyke’s idea had people intrigued. In December 1942, British prime minister Winston Churchill ordered that research on what was now being called the “bergship” should begin with the highest priority. He insisted, however, that the first stage of the research should focus on trying to build the gigantic craft out of an already existing iceberg or ice floe. But this didn’t last long. It became quickly evident that nothing natural would be sufficient for the cause. Most of the available ice structures either had too small a surface above the waterline, or they were too thin and brittle to survive the harsh weather and waves of the Atlantic (the thickness of the ice pack even at the North Pole was only about three and a half meters).

So they would have to build one. It would have to be seaworthy enough to withstand nature, have a large enough deck to support air operations, and be able to propel itself and at a high enough speed to prevent it from drifting in the wind. And, of course, it had to be hard to sink.

After two months of experimentation, it looked as though Geoffrey Pyke’s big idea was dead on arrival. Mechanical stress tests had shown that ice was far too brittle to be used to build a combat-ready warship. As a structural material, it was too unreliable under pressure—it was tremendously difficult to predict its reaction to explosives or other modern weapons. Scientists were extremely frustrated by conflicting data. In several tests, it was determined that ice could handle about 22.5 kilograms of stress per square centimeter before rupturing. But then every so often, an ice beam would rupture at only 4.9 kg/cm 2.

The verdict was in: Ice wasn’t safe as a construction material. It couldn’t be trusted.

But as Pyke and the British military and civilian leadership digested this sad news, a discovery from the other side of the Atlantic rekindled the spirits of those hoping to build the bergship. Two chemists at Brooklyn Polytechnic, Hermann Mark and Peter Hohenstein, not incidentally Pyke’s former professor and his assistant, announced that the inclusion of a small amount of wood pulp in ice dramatically improved its mechanical properties. Wood pulp is ground spruce or pine wood—essentially the raw material that makes up newspapers. Or papier-mâché. Mark and Hohenstein named their new discovery after the inventor of the bergship project: pykrete.

Pykrete was a game changer. A 15 percent mixture of wood pulp frozen into ice was exponentially superior to regular ice. You could hit a chunk of pykrete with a hammer and it wouldn’t break. You could shoot it with a gun. Nothing. A bullet would penetrate the same distance into pykrete as it would into a cement block. A one-inch column of pykrete could support the weight of a car. And it takes much longer than normal ice to melt. Best of all, it still floats.

Speaking of shooting guns at pykrete, one of the best anecdotes of this story apparently occurred at the Quebec Conference in August 1943. All of the bigwigs of the western part of the alliance were there: FDR, Churchill, and all of their civilian and military leadership (Stalin was invited, but could not attend). During one of the meetings, Lord Mountbatten pulled out a chunk of ice and a block of pykrete to show the British and American admirals and generals the potential of the new material. He drew a pistol and blasted the block of normal ice. It did what you’d expect, shattering into hundreds of pieces. Then he shot the pykrete. Not only didn’t it shatter, but the bullet just bounced off the material and almost hit American admiral Ernest King, Chief of Naval Operations.

The demonstration was ill-advised, foolish, and almost deadly. But it worked. Roosevelt, Churchill, and the military brass were convinced, and ordered Mountbatten to give Pyke the blessing to begin producing and testing large amounts of pykrete in secret. Pyke had already set up shop in the rear of a refrigerated meat locker in London, hidden behind a row of frozen dead animals. British commandos disguised as butcher’s assistants guarded the experiments, and when Mountbatten visited to check on progress, he too had to disguise himself (as a lowly civilian) to maintain operational security.

At the same time, the Engineering Division of the British National Physical Laboratory worked on strength tests, and the Road Research Laboratory of the Department of Scientific and Industrial Research investigated pykrete’s explosive resistance. All of this was done under the general direction of the Department of Scientific Research of the British Admiralty. And all of the testing was successful.

With laboratory (and meat locker) experimentation and production completed, and with the requisite signoff from the British and American leadership, it was time to scale up the project. But where, oh where, could they perform the scaled testing? You needed something far enough away from the war to keep the experiments safe from German guns (and spies), remote and spacious enough to give you the room to conduct large experiments without giving away the secret (the Thames River wouldn’t do), and cold enough to do the year-round testing on your bergship (so Miami was out of the question).

Oh… Canada! The True North strong and free! The perfect place to test our iceberg aircraft carrier.

Jasper National Park in Alberta is the largest national park in the Canadian Rockies, spanning more than forty-three hundred square miles. Even in its warmest month (July), the temperature rarely reaches 70 degrees. It’s big, it’s cold, it’s remote. It’s perfect.

Two lakes, Patricia Lake and Lake Louise, were used for testing, The Patricia Lake tests focused on the problems that might be encountered during the construction of the bergship, and on making scientific observations regarding the behavior of pykrete in the middle of summer (which might sound like something a five-year-old could do—“Hey, it melts”—but it was important to know the thermal properties of ice at very specific levels). To do this, the team constructed a “small” prototype bergship—sixty feet long, thirty feet wide, and weighing a thousand tons. Apparently the secrecy of the project was so great that most of the workers (largely conscientious objectors who refused to fight in the war) had no clue what they were working on.

The really fun stuff happened at Lake Louise. It was the job of the Louise team to determine the strength of the ice itself. This meant blasting it with artillery and bombs, and trying to blow holes in the sides with torpedoes. According to legend, when Lord Mountbatten visited the site, he decided to test things for himself. He pulled out a shotgun (somehow he always seemed to have some kind of firearm lying around) and tried to take a chunk out of the side of the pykrete block. To his smug amusement, the stunt didn’t make a dent.

But Mountbatten wouldn’t be smiling for long. The testing at Lake Louise exposed the project to an unfortunate truth: To make the bergship impervious to bombs and torpedoes, the hull would have to be at least thirty-five feet thick . For comparison, the belt armor on an Iowa -class battleship of World War II was 12.1 inches thick. This would mean a need for the manufacture of 1.7 million tons of pykrete, just for a single ship. According to a report written just following the end of the war, to produce this much pykrete would have required a manufacturing plant covering a hundred acres of land—more than seventy-five football fields, or about the size of Vatican City. As a result, a single full-sized bergship would cost more to produce (in money, labor, machinery, and other resources) than an entire fleet of conventional aircraft carriers.

And yet if Habakkuk was the only possible way to win the war, then no amount of money or resources was too much. Right?