Desparately seeking solutions to the U-boat threat, Britain actually planned to build an unsinkable aircraft carrier out of ice! The HMS Habbakuk was the brainchild of Goeffrey Pyke, inventor of "Pykrete", a mixture of ice and wood pulp. Pykrete could be hammered and sawn like wood and was incredibly slow-melting despite being 90% water. The 280,000 Pykrete cubes needed for construction would take eight months and 8,000 workers to make in Canada. The 2,000-foot long monster "berg-ship" would displace two million tons and have an incredibly deep draft, keeping it out of most harbors. The inside would be hollowed out for quarters, hangars, and a massive refrigeration plant with walls 50 feet thick. Twenty-six electric engines, each in its own nacelle with a propellor, were fed by a generating plant. Speed was slow and manuverability nearly non-existent, but Habbakuk could provide an airbase capable of handling long-range, twin-engined land planes, and could not "sink" as it was already water! The high labor costs of construction and breakthroughs in ASW apparatus and codebreaking significantly lessened the U-boat threat enough to melt away official interest in the "iceberg carrier".

In "Grand Fleet", however, no Allied convoys had made it through to Arkangelsk by late 1942. Russia is on the ropes and desperately needs supplies to stave off defeat. The fresh frozen Pykrete carrier Habbakuk joins a critically important convoy off Newfoundland and, with other ships, fends off Luftwaffe air attacks and succesfully escorts the convoy to safety. Russia squeaks by and begins to build up for an offensive to repel the Axis invaders.

The Allies wondered what to do with the ship, now that her duty was done. The Soviets wanted it as an offshore prison ship in Siberia, but the Americans took it across the Polar Route to Alaska to use as a ready-made housing project for Eskimos displaced by the Japanese occupation of Attu and Kiska. They politely refused. Still relatively intact after the war, it was towed to Bikini Atoll for the A-bomb tests where the above-water portion was vaporized by the explosion. The lower portion bobbed up and caused much concern and disbelief among mariners who sighted the diminishing iceberg adrift in equatorial waters.