Germany’s U-boats in World War II, it posed a huge problem for the British, who found themselves short on the resources needed for anti-submarine warfare. The treaty of Versailles that ended WWI forbid Germany from building new submarines, so why have destroyers and aircraft that could hunt submarines at all? A piece of paper had eliminated the U-boat threat to England in the future.

Well, the Germans just built U-boats without telling anyone about it.

The Problem

When war broke out about 100 U-boats scattered into the Atlantic almost like mobile and invisible landmines just waiting for a hapless merchant ship to stubble into them.  The Atlantic is immense and the Royal Navy did not have enough ships to hunt all these U-boats down and the U-boats were smart enough to position themselves out of the range of allied aircraft.   What if there was a way to extend their range with floating bases out in the Atlantic they could land and refuel on.  Not aircraft carriers, which the Royal Navy needed to protect its own surface ships at sea, and long-range bombers couldn’t possibly land on them but something else, like a huge barge. The war meant materials like wood, steel, paint, engines, and other supplies for making large ships were already spoken for.  Enter Geoffrey Pyke, who had an interesting idea: what if they made a huge aircraft carrier out of a unique mixture of wood, pulp, and ice? The idea was to be called “Project Habakkuk.”

Pike was a journalist, educationalist, and inventor.  He was already well known for escaping from an internment in Germany during World War I. He was recommended to the Chief of Combined Operations named Lord Mountbatten by cabinet minister Leopold Amery. So he worked for the Combined Operations Headquarters alongside his friend, J.D. Bernal, and was regarded as a genius.

Pyke’s Solution

Living up to his wonderboy reputation, and as Lord Zuckerman described him as “not a scientist, but a man of a vivid and uncontrollable imagination, and a totally uninhibited tongue,” he came up with the Habakkuk idea while he was organizing the production of M29 Weasels for Project Plough in the United States. Project Plough was a scheme to create an elite unit to be assigned in the winter operations in Norway, Romania, and the Italian Alps. How could they create a floating island base for aircraft and even flying boats to use in the mid-Atlantic while scouting for U-boats?

By making them out of Atlantic icebergs, of course.

You see, using ice would only require 1% of the energy that was usually needed to make the same mass using steel. So here’s his proposal: Get an iceberg, be it natural or artificial, and then level it so that planes could use t as a runway. Also, hollow it out so that it could shelter the aircraft.

A block of pykrete. (CyranoDeWikipediaCC BY-SA 3.0, via Wikimedia Commons)

He immediately sent the proposal through the diplomatic bag to the Combined Operations HQ while he was in New York. He made sure that nobody would know of his genius plan and labeled it so that only Mountbatten could open the package. In turn, Mountbatten passed Pyke’s proposal to Churchill, who was excited about the idea. “Genius!” he probably exclaimed.