Because of his previous research into the changes in the arrangement of the crystals in the different layers of a glacier before the War he was asked for advice on whether if a battalion of commandos were landed in Norway, could they be hidden in shelters under glaciers. His knowledge on the subject of ice then led to him in 1942 being recruited for Project Habakkuk. This was a secret project to build an ice platform in mid-Atlantic, which could be used to refuel aircraft. To that end he investigated the recently invented mixture of ice and woodpulp known as pykrete. He carried out early experiments on pykrete in a secret location underneath Smithfield Meat Market in the City of London.