The Ice Fleet

Posted on 04. Mar, 2009 by Kerry Banks in Canada

A 10-minute drive outside Jasper, Alberta, a plaque stands on the shore of scenic Patricia Lake. As historical plaques go it is nothing special—modest and low-tech with a few words and illustrations. But the story that inspired the plaque is anything but ordinary. The memorial marks the site of Project Habbakuk, one of World War Two’s most bizarre military experiments. The aim of Project Habbakuk was to build a fleet of massive “iceberg ships” from a mixture of frozen water and wood pulp-–unsinkable aircraft carriers that could protect North Atlantic shipping lanes from German bombers and U-boats. The carriers were to be 600 metres long, 90 metres wide and 45 metres deep and be capable of housing 200 Spitfires, 100 Mosquito bombers and 2,000 crewmen. At the time, the largest ship afloat was the HMS Queen Mary, which weighed 86,000 tons. The ice ships would weigh two million tons.

The outrageous idea arose from the mind of Geoffrey Pyke, an eccentric British scientist who worked as an advisor to Lord Mountbatten, Chief of Combined Operations. In 1942, Pyke began wrestling with one of the Allies’ most daunting problems. In the mid-Atlantic, beyond the range of the land-based aircraft, was a stretch of ocean where Allied shipping was being cut to pieces by the merciless German submarine fleet. What was needed, Pyke decided, was a means of providing air cover for the merchant ships. His solution was icebergs that resembled aircraft carriers. The platform would melt eventually, of course, but Pyke believed that a large enough piece of ice would last at least a few months—longer if it were insulated on the outside and cooled from within by a refrigeration system. Better yet, the platform couldn’t be sunk; and even if damaged by torpedoes or bombs, repairs could be made simply by freezing new chunks of ice into place. In battle, the ice ships could put their onboard refrigeration systems to effective use by spraying super-cooled water at enemy ships, icing their hatches shut, clogging their guns and freezing enemy sailors to death.

Winston Churchill was receptive to the idea. After reading the formal War Cabinet report on the Habbakuk project in December 1942, Churchill shot back a memo stamped Most Secret. “I attach the greatest importance to the prompt examination of these ideas,” he wrote. “The advantages of a floating island or islands, even if only used as refuelling depots for aircraft, are so dazzling that they do not need at the moment to be discussed.”

But before the plan could be put into anything even close to reality, Pyke had to solve one fundamental problem: ice melts. Early in 1943, two researchers employed by Pyke discovered that by mixing wood pulp, sawdust, or cotton wool with water and freezing the slurry, they could create a substance that still floated nicely but was much stronger and less brittle than plain ice. It could be shaped with ordinary woodworking tools and it melted much more slowly than ice. The material was dubbed pykrete in honour of Pyke.

Pyke excitedly showed the stuff to Mountbatten, who was so similarly afflicted that he rushed into Winston Churchill’s bathroom and in a scene that sound like something out of Monty Python, dropped a block of the stuff in the PM’s bath water. Churchill’s bath may have been ruined, but he gave Mountbatten the go-ahead. Pyke was ordered to produce pykrete in large quantities to test and perfect it. Utmost secrecy was required, so he set up shop in a refrigerated meat locker in a Smithfield Market butcher’s basement; his “shop assistants” were disguised British commandos. The work was carried on behind a protective screen of massive frozen animal carcasses.

The butcher’s backroom soon produced enough samples for Mountbatten and Churchill to take their pykrete show on the road. Mountbatten unveiled the invention at a tense secret meeting of the Allied chiefs of staff at Quebec City’s Chateau Frontenac Hotel in August 1943. 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. The bullet ricocheted off the block, grazing the trouser leg of U.S. Admiral Ernest King and ended up in the wall. Mountbatten’s unorthodox demonstration had the desired effect.

In the winter of 1943, Allied scientists began constructing a 1,000-ton, 18-metre-long, nine-metre-wide prototype on Patricia Lake to gather information about how it could be insulated and cooled. The ice ship was disguised with a tin roof to make it look like a boathouse. Although the vessel would move slowly, and the enemy could hardly fail to see it coming, this hardly mattered. “Surprise,” Pyke theorized, “can be obtained from permanence as well as suddenness.” The experimental craft proved seaworthy and its immense hull was as strong as Pyke had predicted, but Mountbatten eschewed the scientist’s reports for a more direct testing method: hauling out a shotgun and vainly trying to blow a hole in the side of their precious prototype.

The engineers managed to keep the model frozen during the entire summer of 1943. Unfortunately, the astronomical cost of deploying a full-size ship quickly became apparent. In the end, the HMS Habbakuk was never built. Land-based aircraft were attaining longer ranges, U-boats were being hunted down faster than they could be built, and the U.S. was gaining numerous island footholds in the Pacific–all of which contributed to a reduced need for a vast, floating airfield. The prototype was abandoned and when the ice ship finally thawed, its skeleton of wooden forms and refrigeration equipment sank to the bottom.

In the 1970s, the remains of the Habbakuk were found by divers and studied by University of Calgary underwater archaeologists. Later, in 1989, a plaque to commemorate the strange ship was erected on Patricia Lake’s southern shore. However, the plaque offers no clue to the fate of Geoffrey Pyke. After the war, eager to convey his unconventional ideas, he wrote and broadcast. He campaigned against the death penalty and for government support of UNICEF. But the more he thought about trying to achieve a better world, the more pessimistic he became–it seemed that human nature was antithetical to innovation in general and his ideas in particular. He was widely mocked in the media of the time, and a sense of gloom overtook him. On February 21, 1948, Pyke committed suicide by consuming sleeping pills.