Pykrete Prototype

Birth of the Boathouse

Wood planks being laid for the prototype. Photo Courtesy of National Research Council Canada Building the prototype. Photo Courtesy of National Research Council Canada Laying ice blocks on the floor of the prototype. Photo Courtesy of National Research Council Canada Framing the prototype. Photo Courtesy of National Research Council Canada Ductwork for refrigeration. Photo Courtesy of National Research Council Canada In February 1943, construction of the Habbakuk’s scale model began on the frozen surface of Patricia Lake. The delay in construction was due to the late arrival of all of the supplies via railroad. In the interim, the workers worked on ways to bond the blocks of ice which were being cut from the surface of the lake. As this was being done, another group prepared for the construction of the model by clearing the area, laying the wood floor and framing the walls. The wood flooring and walls were then covered with asphalt, and tinsmiths began construction of the ducts which would go in the interior of the boat.

Sometime between March 1st and the 6th, the first layer of lake-ice blocks were placed on the newly laid wood floor. However, it was quickly discovered that the long train trip caused irreparable damage to the materials. Many of the joints of the piping, which were to be used inside the boat for refrigeration purposes, were damaged causing the proposed brine-coolant to leak out of the pipes. This led to the decision to use cold air forced through the piping instead. Many of the people overseeing the project began to express doubts regarding its viability.

By March 20th, the piping throughout the floor of the structure, the ducts and all of the wall piping had been installed. As more and more ice was added to the structure, the floor began to bow underneath the weight. To test its capability for floating in water, and to relieve some of the strain from the floor, it was cut loose from the ice. Promisingly, the model sank to the level of the ice flooring inside and floated.

The crews continued to work on the model as it floated in the lake, and by the following week, a third layer of ice blocks, with a channel cut into it, was installed. This channel provided a duct for the refrigeration unit on top of the third layer. Construction continued until April 10th, when the remaining machinery for the refrigeration unit was put into place. The final piece to be added was the roof, which was meant to protect all of the machinery inside as well as the open surface insulation. This roof, much like those found on boathouses, resulted in the name given to the model – the boathouse. The final dimensions of the boathouse were 60’ x 30’ x 19 ½’.

Stop the War and I'll Melt With You

Habbakuk Prototype floating on Patricia Lake. Photo Courtesy of National Research Council CanadaOn April 16, 1943, after the successful building of the model, $1 million was allocated from the Canadian budget for building the full-scale model Habbakuk. The cost of actually building this vessel was estimated at close to $70 million, which was still less than half the cost of a traditional vessel of its size. The 1:10 model and all of the research to date had cost only $150,000.

However, by this time, the Battle of the Atlantic had taken a turn for the better and it seemed as though the need for the Habbakuk was all but gone. Convoys were now crossing the Black Pit with no losses. Other advancements, such as the construction of better long-range aircraft, centimetric radar and airbases in Iceland, were able to successfully eliminate the threat of U-boat Alley. Many of the key people involved with the building of the model felt that building a full-scale model was possible, it just wasn’t strategically necessary. Churchill was not happy with the idea of ending the project, which he had so fully supported, so he and the Canadians convinced the hesitant Americans to become involved. The American military eventually agreed to buy into the idea, but never acted upon it. The project was quietly killed within the year.

The Canadians ordered that the prototype should be stripped of everything reusable and the refrigeration units turned off. The cold temperatures in Canada kept the boathouse frozen throughout the entire summer. In the fall of 1943 the once-revered Habbakuk project sank to the bottom of Patricia Lake with the melting prototype, taking her secrets with her.

The Fate of the Futuristic Project

Habbakuk Prototype floating on Patricia Lake. Photo Courtesy of National Research Council CanadaAlthough the operation failed, the project itself had been a success. The prototype boathouse that was built, along with the invention of Pykrete, proved that the concept was demonstrably sound and could work in other conditions and for other needs. For instance, the possibility of using as a landing craft in either the Mediterranean or France was considered. If the need for the ice ship had persisted, it is likely that Churchill and the Canadians would have been more forceful in continuing the project and the world might actually have been able to see the ship that for many years was classified as “Most Secret”. However, the costs associated with such an undertaking, combined with the war turning in favor of the allies, proved that such a project was no longer required. Desperate times called for desperate measures; however, those were no longer desperate times.

Today, the remains of the prototype can still be found on the bottom of Patricia Lake. Although the ice has long since melted, the wood used for framing, cut-outs for ductwork as well and asphalt have formed a pile that looks much like the mess of a construction site. The cold waters of Patricia Lake have preserved the wood and materials quite well, and the only risk of losing them forever is found on the edge of the remains, where a steep underwater cliff threatens to swallow all of the wreckage.

The technology invented during the time of need could still have practical applications today. And although the project never reached fruition, this should not detract from the fact that this futuristic and almost unbelievable project was proven possible.