Word War II, just like the other wars, produced so many plans and operations. Some were successful, others failed, and some did not commence because they sounded insanely impossible, unrealistic, too risky, or probably deemed unnecessary. There were also those that were carried out but did nothing except waste time and resources. Here are some of those lesser-known and never-realized plans during the Second World War.

Operation Bernhard, the Nazi’s Mission to Fake British Money

By 1939, SS Major Bernhard Kruger, the leader of an SS department that worked on falsifying passports and some other legal diplomatic documents, formulated a plan to sabotage the British Empire and the United State’s economies. With the help of SS officer Alfred Naujocks, they decided to produce fake currency, too, as part of the wartime intelligence campaign. Kruger organized a top-secret printing operation in one of the concentration camps, the Sachsenhausen. There, he forced Jewish prisoners with printing and engraving skills to work on his plan.

Operation Bernhard forged more than a million pounds in fake banknotes. They were able to use this money to pay spies all over the world, as well as other transactions that involved foreign governments like Italy. However, they were not really able to influence the British or the American economy. When the war was coming to an end, all of the remaining fake currency was thrown into Lake Toplits in Austria, where it was soon discovered in 1959.

Operation Tannenbaum, Nazis’ Plan to Invade Switzerland

It’s fairly easy to say the Fuhrer did not adore Switzerland at all. In 1941, he told Mussolini,

Switzerland possessed the most disgusting and miserable people and political system. The Swiss were the mortal enemies of the new Germany.

So the Wehrmacht began the preparations to invade Switzerland right after France surrendered in 1940. The plan would be called Operation Tannenbaum. The details of the plan were revisited and revised multiple times, but Hitler never really ordered an attack for some unknown reason. The guess was that Hitler, despite his hate for Switzerland, understood that invading a nation with armed 435,000 citizens with weapons that could rival those of the Nazis was fairly impossible.

Project Habakkuk, Aircraft Carrier Made of Ice

The idea dawned on Geoffrey Pyke, a British inventor, when in early 1942, Britain found itself in a desperate situation when German U-boats were wreaking havoc on the vital supply lines of Britain. The United States had just joined the war at that time, but effective large-scale submarine weapons and tactics were yet to be fully developed or made use of. And so Prime Minister Winston Churchill thought of a solution, which was a massive aircraft carrier that would sail to the middle of the Atlantic so that airplanes stalking and sinking German U-boats would have a refueling and landing location if needed.

Pyke conceived the idea of a floating island as huge as an aircraft carrier. The initial idea was to use icebergs as a floating airport. However, they easily shatter with the lights of explosives. Additionally, the fact that these icebergs were not stable and could tip or rollover, made their use implausible. To resolve this, Pyke experimented with combining ice and wood pulp called “pykrete” after him.

Both Lord Mountbatten and Churchill okayed the idea after being given a small pykrete demo. The 60 by 30 feet block that weighed 1,000 tons of pykrete was soon produced. However, the weight, cost, and resources required to produce a full-scale version later caused the project to halt, and Project Habakkuk was discontinued in December 1943.