Page 11 - April 2019

Nevertheless Dr. Mackenzie proceeded, with
assistance from western universities including the
University of Alberta, to research the properties of
ice.

Initial ice testing was conducted at Lake Louise but a
less visible locale was needed for the secret project.
Dr. Mackenzie chose Patricia Lake because it was
already closed to the public for ski paratrooper
training, it was close to rail facilities, and labourers
were available from a nearby camp for conscientious
objectors. Work began on the test model in mid-
February 1943 when a patch of the frozen lake was
cleared of snow and wooden framing and flooring
was erected. The first layer of ice was laid on the
flooring in early March. The entire test model was
covered by a roof giving the test site the appearance
of a boat house.
Problems arose almost immediately with the proposed coolant system – a brine coolant circulated through
ducts in the pykrete hull. Nevertheless, a scale model, measuring 60 feet long and 30 feet wide, weighing
1000 tons, and kept frozen by the use of air circulation from a 1-horsepower motor, was completed that

summer.

While the test model did in fact float, other engineering and design problems had arisen. The complex coolant
system would require piping throughout the icy structure doubling or tripling construction costs.
Three hundred thousand tons of wood pulp would be required to produce the necessary quantities of pykrete

causing severe impacts on the pulp and paper sector. Additionally, there was no possibility of building the full-
size pykrete aircraft carrier by spring 1944, the originally established target date. Other technological
innovations such as the introduction of longer range patrol aircraft with improved radar detection capabilities
had eliminated the “Atlantic gap” and shipping losses were declining rapidly. By mid-May 1943 German U-
boats were ordered to leave the mid-North Atlantic.

In June 1943 all testing in Canada was stopped, and
despite some flagging support for the project at the
August 1943 Quebec Conference involving Churchill,
Roosevelt and Mackenzie King, by October 1943 the
project was essentially dead. The test model on Patricia
Lake had been abandoned over the summer but it took
another year before it melted and sank to the bottom of
the lake.
Today, metal piping and asphalt strewn across the lake
bottom are all that remain of the would-be aircraft
carrier. Divers can visit the wreckage, and a
commemorative plaque along the shoreline of Patricia
Lake memorializes one of Canada’s more unusual
wartime projects.