Building ships from ice: Habbakuk and after

A remarkable study was carried out during the Second World War on the feasibility of building large ships from ice. It received support at the highest political level because of the need for floating platforms to support aircraft operations. Extensive investigations were carried out on the mechanical properties of plain and reinforced ice and on the structural and operational characteristics of the proposed vessels. Investigations on methods for reinforcing ice led to the development of ‘pykrete’, a frozen mixture of water and wood pulp that was appreciably stronger and tougher than plain ice. The studies on the structural and operational characteristics of the vessels showed that the work required to design, construct and demonstrate the effectiveness and safety of the ships would be far greater than originally thought. This paper gives an abbreviated description of the work that was done, based on project files in Great Britain and Canada, which led to the conclusion that it was technically possible to build ships from ice, but that during wartime it would be too costly in terms of manpower and strategic materials.