Project Habbakuk–The Plot to Build an Impregnable Island of Ice

The USS Sargent Bay, an escort class American aircraft carrier from WWII. Uptick in the production of these ships made the Habbakuk obsolete before it was even created.

The USS Sargent Bay, an escort class American aircraft carrier from WWII. Uptick in the production of these ships made the Habbakuk obsolete before it was even created.

People are never more creative than when they’re trying to come up with new ways to kill each other. The ancient genius Archimedes repurposed cranes as a superweapon to fend off the Romans. Nikola Tesla devised a theoretical particle beam weapon that could wipe out enemy armies hundreds of miles away. Not to be outdone, the Nazis had a plan to build a giant orbital station that could direct sunlight into a beam that could incinerate cities and armies in the blink of an eye. Smaller in scale but somehow more insane was the US Army’s nuclear rifle, a weapon that was actually built and deployed, although thankfully it was never used.

Something about warfare seems to encourage lateral thinking. However, while using cranes and sunlight for weapons could seem like good ideas in the right circumstances, most people would not look at ice and see a potential weapon. Geoffrey Pyke was not most people. In 1942, with Allied shipping coming under almost constant attack from Nazi submarines and with land based Allied planes unable to reach the mid-Atlantic to protect them, Pyke proposed a revolutionary concept: an aircraft carrier made of ice.


The biggest ship in history

To say that the ship Pyke proposed would have been massive is an understatement. The Habbakuk II — second of the proposed models and the one favored for design– would have displaced 2.2 million tons of water and it would have been spacious enough to accommodate 150 fighters and twin engine bombers. It would have measured 300 feet wide and up to 2000 feet long, and it would have been powered by 26 externally mounted electric engines that would have supplied 33,000 horsepower. The top of the craft would have been flattened to construct an airstrip from which the fighters and bombers could launch.

The walls of the craft would have been composed of 40 foot thick blocks of pykrete, a mixture of ice and 14% wood pulp that was both strong and durable. It also took longer to melt than normal ice, and it could be cut and shaped much like wood. damage from bombs and torpedoes could be easily repaired by simply pouring water into the damage and allowing the ship’s cooling system to freeze it.

Pyke envisioned Habbakuk crafts plying the waters of both the Atlantic and the Pacific, acting as massive platforms for Allied air squadrons (Side Note: the name Habbakuk came from an Old Testament verse from the Book of Habakkuk, 1:5: “Behold ye among the heathen, and regard and wonder marvellously: for I will work a work in your days, which ye will not believe, though it be told to you.” Pyke misspelled the name Habakkuk early in the project. The typo stuck.) The ice craft would give a huge advantage over more traditional aircraft carriers because they could house larger planes in larger numbers. However, there were several harsh realities that sunk the project before any of the massive ships could be built.


Dead in the water

The Achilles Heel of Project Habbakuk– like many ambitious projects from history–was simple economics. While the pykrete itself was relatively inexpensive to produce, securing enough wood pulp to build ships the size of the proposed vessels would have put a big strain on the paper industry. In addition, the ships would require massive amounts of steel both for the skeleton around which the pykrete hull would be built and the cooling system to keep the pykrete from melting and deforming the shape of the ship. This steel could be put to better use building conventional ships and planes with proven track records of success.

In addition to being impractical economically, the shifting circumstances of the war rendered Project Habbakuk obsolete before it could be built. The British government secured permission from the government of Portugal to establish airbases on the Azores, allowing Spitfires to extend deeper into the Atlantic. Also, Allied air forces started to use longer range fuel tanks, allowing planes based on the British Isles to fly further and longer on patrol. Finally, more escort carriers were attached to shipping convoys. While not as revolutionary as the Habbakuk, the flat tops managed to fend off German wolf packs just the same.

By 1943, Project Habbakuk was dead in the water. The closest Geoffrey Pyke’s ambitious idea came to being a reality was a 60 by 30 foot prototype built on Lake Patricia near Jasper, Ontario, Canada. It was cooled by a 1 horsepower motor. When the project was scrapped, the motor was taken out and the ship was left to melt. By the summer of 1944, the only tangible result of Project Habbakuk had sunk to the lake bottom.



“Project Habakkuk.” March 31, 2014. Wikipedia. March 29, 2014. <>

Collins, Paul. “The Floating Island.” Cabinet. Summer 2002, Issue 7. Retrieved from:

McMurtie, Francis C. “Strange Story of HMS Habbakuk.” The War Illustrated. April 12, 1946. 9(230), pg 774. Retrived from:

“The Habbakuk Project.” 2001. The Royal Naval Museum. March 29, 2014. <>


3 thoughts on “Project Habbakuk–The Plot to Build an Impregnable Island of Ice

    1. Andrew Kincaid Post author

      I vaguely remember seeing that. Might have to give it a rewatch. It’s a pretty remarkable material for just being ice and wood pulp haha

  1. Pingback: The Machine Gun’s Grandpa: The Puckle Gun | Oddly Historical

Comments are closed.