Project Habakkuk was a plan by the British in World War II to construct what from ice?

Question

Which ship was sunk in World War II on 17 June 1940 in the course of evacuating British nationals and troops, with the loss of an estimated more than 4,000 men, women and children?

Answer 1

Aircraft carriers
As the mid-Atlantic was out of range of land-based planes and German U-boats were sinking supply ships, the concept was to construct an iceberg, natural or artificial, levelled to provide a runway and hollowed out to shelter aircraft.