IceCraft Carrier

The content below is from Season 2 Episode 27 of the Who’d a Thunk It? Podcast.

Recommendation Segment

  • This episode features another recommendation from my Fiancée Shannon. Tune in to the audio podcast to hear what she decided to recommend.


  • Well who’d a Thunkers, I hope you like history because I have yet another World War 2 episode for you!
    • Today we talk about the story behind the Project Habakkuk. That’s when a Brit named Geoffrey Pyke thought it would be a good idea for the British navy to make an Aircraft Carrier out of ice.
      • Sounds crazy I know.
    • But That was the level of desperation that people were dealing with during WW2. Technology was taking off yet they were faced with the largest scale war that mankind had ever seen.
      • The world atmosphere during WW2 was nuts and that’s why there are so many unbelievable stories to come out of it.
      • A few episodes back I talked about how the American Military was funding the psychologist BF Skinner to train pigeons on how to guide missiles.
      • WW2 is so insane that one time my buddies and I were playing BattleField V (a WW2) game. My one friend made a comment on how the Nazis were so successful in their Blitzkrieg across Europe because they were all given Meth. That’s why their attacks were so fast and how they could fight for 48 hours straight with no sleep.
        • Another friend of mine laughed hysterically and thought he was just joking… But we all assured him that it is a fact. The Nazis weren’t prescribed meth… they were given it like you would give a co-worker a cup of coffee.
        • THAT is how crazy World War 2 was.
    • Now this Aircraft Carrier made of Ice sounds crazy to us now, but at the time it made more sense.
  • Britain is on an island roughly the size of the State of Michigan.
    • Being an island country came with both benefits and draw backs during WW 2.
      • They avoided a land invasion from Germany in 1940 because they are an island nation.
      • But that also means their imported goods all need to come by sea.
    • So Hitler thought if he couldn’t invade them outright that he would cut off their supplies from the outside world.
      • The Nazis had 1,162 submarines (or U-Boats as they were called). They targeted allied supply ships.
      • They used what was called the Wolfpack strategy and it was very effective.
      • The Brits weren’t able to deploy their anti-submarine aircraft because the U-Boats were smart enough to only engage far out at sea… too far for the aircraft of that day to reach.
    • Aircraft Carriers were a good defense against U-Boats. They could transport the anti-submarine planes to where the subs were hiding.
      • Unfortunately with the mass production of tanks, planes, and hand held weapons there wasn’t enough steel to just make more Aircraft Carriers back in Britain.
  • Introducing Geoffrey Pyke
    • Pyke was an orthodox Jew studying law at Pembroke College when WW1 started.
      • But he gave up his studies to become a War Correspondent. He convinced the editor of the Daily Chronicle news to fund a trip to Deutschland in the year 1914. He wanted to get a better understanding of the German people at the time as they prepared for war with Russia.
      • He travelled to Berlin with an American Passport, But it only took 6 days for his suspicious behavior to land him in prison. There he suffered harsh conditions for 13 weeks until he was able to escape.
      • He was able to make it back to Britain and his tale of an escaped prisoner of war became popular among the British people.
    • Leading up to WW2, Pyke was involved in a few projects against the Nazi party.
      • He sent journalist spies to cities across Germany to interview citizens on how they felt about all the antisemitism. He was able to conduct a decent sized poll and gather some significant data. But Pyke was never given the chance to present his findings to Hitler himself… Hitler was too busy invading Norway.
    • Once WW2 was well underway, Pyke set his sights on transporting troops in cold conditions.
      • He was put on a team of scientists and engineers to design a reliable vehicle for transporting troops through snow. It was dubbed operation Plough.
      • Pyke helped design the M29 Weasel that was manufactured by the hundreds in America.
  • So when Britain was faced with this U-Boat problem, Geoffrey Pyke was a likely candidate to find an out-of-the-box solution.
    • In 1942 he envisioned a large iceberg out at sea. He pictured the top of the iceberg cut on a level line for a runway and the middle hollowed out to store planes.
      • Pyke drew up a 232 page document to be sent in a diplomatic bag to the Combined Operation Headquarters. He gave specific instructions that only Lord MountBatten, Admiral of the Fleet should read its contents. Mountbatten (Member of the Royal Family and Royal Navy officer) must have been impressed with the plans because he immediately shared them with Winston Churchill (the acting Prime Minister of Britain at the time).
    • Now Icebergs aren’t Ideal for this.
      • At first, the ice berg AirCraft Carrier seemed like a lost cause. While ice was strong, it was also too brittle to hold up its own weight and easily lost shape under pressure. Ice also melts, which required Pyke to develop a complex cooling system that continuously pumped refrigerant throughout the carrier to keep it frozen.
      • So he and a team of scientist went to work combining wood chips and ice. The result was what they called Pykrete.
  • Pykrete is much less likely to sink than regular ice
    • It also melts at a higher temperature and is much more structurally strong.
    • Pyke had gotten the idea for Pykrete from an Austrian-American Chemist Herman Mark.
      • One of Pyke’s collaborators Max Perutz wrote “Blocks of ice containing as little as 4% wood pulp were weight for weight as strong as concrete. In honor of the originator of the project we called this reinforced ice Pykrete. When we fired a rifle bullet into an upright block of pure ice two feet square and 1 foot thick the block shattered. In Pykrete the bullet made a little crater and was embedded without doing any damage.”
      • As long as the Pykrete stayed frozen, it was as good as concrete.
    • The British Government was short on funds and resources thanks to the U-Boats so the thought was that it would be a lot cheaper to produce a Pykrete Ship than a steel ship.
      • 1 ton of ice take less than 1% of the energy to produce than 1 ton of steel.
      • Lord Mountbatten was sure the Pykrete idea would work. He presented the idea to generals, Ministers, and even President Roosevelt.
  • Project Habakkuk
    • Although it is my opinion that “IceCraft Carrier” would have been the best name for it… The official name was Project Habakkuk.
    • Churchill approved the idea, code-naming it Project Habakkuk, a reference to the biblical book of Habakkuk: “… be utterly amazed, for I am going to do something in your days that you would not believe, even if you were told.” (Habakkuk 1:5, NIV)
      • The ship was supposed to be 1.2 Kilometers long (that is over 13 football fields) and 180 meters across (that is almost 600 feet).
      • They decided to build a pykrete prototype in Patricia Lake, Alberta to test the effectiveness on a large scale model.
  • The prototype required a constant refrigeration system to keep cool. If the temperature of the ship rose above three degrees Fahrenheit, it would start to sag and lose shape. Although the pykrete mixture made the prototype stronger than ice, it also required much more insulation.
    • And negating the one major advantage of Project Habakkuk, Steel would still have to be used to insulate the carrier, which would have drained more resources and made it still more expensive. Plus, because the of the sheer size of this behemoth it would be slow and very hard to maneuver.
    • Even though I didn’t see it in any of my sources, I imagine they would only be able to use the craft in colder climates. I mean imagine trying to sale the IceCraft Carrier to the Bahamas!
    • Wood was also in short supply during the war, and building a pykrete aircraft carrier would have negatively impacted paper production. Which the British needed at the time. At the beginning of the war they were cranking out propaganda pamphlets and dropping them all over Europe.
    • Project Habakkuk was great in theory, but terrible in practice.
    • The British turned their attention to more practical projects. What remains of the prototype still lie at the bottom of Patricia Lake along with an informational plaque (thanks to the Alberta Diving Council).
  • The idea of an enormous IceCraft Carrier is really cool to think about, but terribly impractical.
    • And thank goodness they never went through with it. Could you imagine working in a place where it never got above 3 degrees Fahrenheit (that is -16 degrees Celsius)?
    • Thanks for listening Who’d a Thunkers! Until next week!


It may seem odd that I included this video, but without it this episode wouldn’t exist. I am obsessed with this guy’s ear cleaning videos and he compares a dense earwax material that is made denser by ear hair to Pykrete. One minute and 30 seconds in to the video he talks about Pykrete and Project Habakkuk and after hearing it I immediately started researching lol.