Paul's Ride Guide: Goodbye Ice, Hello Pykrete

Back in 1942, as World War 2 ground on relentlessly, a Canadian named Geoffery Pyke worked on a secret project which would use ice to build an offshore refueling platform, somewhat akin to an aircraft carrier but made from a special concoction called he called Pykrete.

Yes, crazy as it sounds at first, the idea actually has some merit. Partly because their idea didn't just use ice, but was a cellulose mixture, added in the form of wood pulp, which made the structure considerably more durable. This came about after the higher ups in the British Military thought the idea might float and put a task force to work on the project, including molecular biologist Max Peruz, who had been "recruited" ( basically under arrest) because he was Austrian. The experiments produced a mixture called Pykrete, named after Pyke himself of course, which had numerous other advantages.

Consider the following...

Pykrete had a crush resistance greater than 3,000 psi
The wood pulp in the ice makes it quite stable at higher temperatures
The low thermal conductivity makes the melting rate very slow
Building a ship or platform required very little metal, which was scarce
Since the ship or platform hull contained no metal, it would not attract mines
It would also handle submarine attacks much better than a ship made of metal, absorbing the shock and withstanding the explosions of a torpedo.

About 450 km from my home in Calgary lies Patricia Lake, where an experimental Pykrete boat was built back in 1943. One could say this prototype was a success but several factors sunk the project, particularly the shift in the war effort, as the Allied Forces began to make advancements. Interestingly, the experimental boat, "The Habbakuk", remained afloat for several Summers and remnants can still be seen to this day at the bottom of the lake.

artists conceptual rendering of the very large Pykrete platform ship.

Even if the Pykrete boat never got afloat, the idea of using this frozen water and pulp mixture to build structures has been the focus of several experiments in recent years, including the ice dome created by students at Eindhoven University, Holland in co-operation with residents of Juuka, Finland.

Much of the work was based on the experiments of Tsutomu Kokawa, who has been working on ice domes since the 1980's. Inflating a giant bubble which was held in place by a net, staked to the ground, work crews covered the dome with a layers of slush and sawdust, which is the premise of Pykrete. Once the Pykrete layer was built up and solidified, the balloon was deflated and removed, leaving the structure free standing.

Unfortunately, the dome only stood for a few days before the roof collapsed, likely due to the large 50 m span. Smaller versions of this concept have been built and lasted for several months.