Project Habakkuk: The Wartime Plan to Build Ships From Ice

Sea Hurricane fighters aboard escort carrier HMS Avenger (D14) during the Second World War. (Image: Royal Navy. Sea Hurricane fighters aboard escort carrier (D14) HMS Avenger)

World War Two was a desperate time, and desperate times call for desperate measures. There were a whole host of bizarre plans put forward on Allied and Axis sides alike. Project Habakkuk came from the UK War Office’s Combined Operations Headquarters.

The secret programme was the brainchild of English journalist and inventor Geoffrey Pyke, who sought a way to counter German U-boat activity in the Mid-Atlantic, an area beyond the range of land-based planes where conditions were often cold and inhospitable.

Project Habakkuk investigated the possibility of building an aircraft carrier from pykrete - a mixture of ice and wood pulp. (Image: Jerzy Strzelecki. Project Habakkuk investigated the possibility of building an aircraft carrier from pykrete – a mixture of ice and wood pulp)

These challenges were made even more difficult by the shortage of materials like aluminium and steel for shipbuilding. As a result, the visionary Pyke proposed using something that was readily available: ice. Icebergs, it was suggested, could be adapted as de facto aircraft carriers. And to ensure these floating airfields didn’t simply melt, Pyke suggested using pykrete – a mixture of ice and wood pulp.

Not only was pykrete stronger than plain ice, it also melted incredibly slowly. The UK Prime Minister, Winston Churchill, was enthusiastic, and asked Lord Mountbatten to demonstrate Project Habakkuk’s potential for the admirals.

A Sea Hurricane takes off from an aircraft carrier during WW2. (Image: Royal Navy)

Mountbatten (a long-time friend of Pyke’s) produced a block of ice and a block of pykrete and fired at both with his service revolver. The ice shattered as the round pulverised it, but the second bullet ricocheted off the pykrete block and grazed the trouser leg of Admiral Ernest King, Commander in Chief of the US Fleet during World War Two. Pyke and Mountbatten had got their point across.

Though steering remained an unresolved problem, scale model tests on a lake in Alberta, Canada, proved promising.

Fairey Swordfish on the deck of HMS Tracker (Image: Oulds, D C (Royal Navy). Fairey Swordfish on the deck of HMS Tracker)

Had it been built, the “HMS Habbakuk” would have been 2,000 feet long with a beam of 300 feet and a depth of 200 feet. The War Illustrated suggests that it would have had hangar capacity for 200 Spitfires or 100 Mosquitos, including work shops and everything else required to keep the aircraft operational. The ice carrier would accommodate 3,620 officers and men. (Visit io9 for an artist’s impression of what such a ‘vessel’ might look like.)

But rising costs, the development of longer-range aircraft and the use of airfields in the Azores, from which to hunt U-boats, all conspired to forever shelve Project Habakkuk, leaving little more than some scale test articles and classified documents to melt into history.

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