In 1950s-era Germany, the British forces which had been stationed there after World War 2 were understandably nervous about an invasion from the Soviet Union. The Cold War had begun, the Iron Curtain was in place, and Stalin was making every effort to compromise Germany’s capacity for another war despite attempts by the U.S. and England to rebuild Germany as the economic center of a stable Europe. Additionally, amid tensions, Stalin had split off the Soviet sector of Germany as a communist state.

It was generally perceived that the Soviet Union possessed overwhelming superiority in conventional weapons, and the threat of a new war with the communist USSR was looming over Europe. As part of the preparations for such a conflict, British forces developed a new kind of landmine to leave behind if they were forced to withdraw from Germany. It was codenamed the Blue Peacock, and it was essentially a nuclear landmine.

The seven-ton Blue Peacock consisted of a huge steel casing containing a plutonium core surrounded by high explosives. Its yield was about ten kilotons, and the plan was to bury and submerge ten such landmines around key targets in Germany in the event of an invasion. The mines would be set to detonate after eight days using a mechanical timer, or alternatively they could be exploded remotely from up to five kilometers away. Once armed, there was also an anti-tampering system which would detonate the bombs within ten seconds if they were damaged or disturbed. The mines were intended to cause massive destruction, and leave radioactive contamination over a large area to prevent subsequent occupation by Soviet forces.

One bizarre proposed design called for a casing capable of housing chickens, with the intent to use their body heat to prevent the electronics from being disabled due to winter’s cold. For this reason, the Blue Peacock is sometimes referred to as the “Chicken powered nuclear bomb.” Another design called for more traditional fiberglass insulation.

Two prototypes of the Blue Peacock were constructed and tested, though never detonated. In July 1957, British army leaders ordered ten Blue Peacock mines, which they planned to station in Germany under the cover story that they were atomic power units. But the project was cancelled before the order could be filled; Hiding nuclear weapons in an allied country was deemed “politically flawed” by military leaders, and the risk from radioactive fallout would have been “unacceptable.”