This May Be the Most Ambitious Ice Sculpture Ever.

During WW2, the British thought they could make an unsinkable ship. Project Habbakuk was formulated to solve the problem of unrelenting U-Boat attacks from the Germans under icy conditions in the Atlantic. Learning a strange lesson from the Titanic, they decided the best way to combat the ice problem in most of Europe was by creating a fortress made from icebergs. With a runway on top and a hollowed out interior for housing aircraft and crew, Pykrete was even created from water and sawdust to ensure balance. I’ll give you three guesses how it worked out.
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https://www.youtube.com/watch?v=VMYSLGnRM88