Blue Peacock (nuclear weapon)

Blue Peacock was the best-known of several names for an early, and less than spectacularly successful, United Kingdom nuclear weapons, an atomic demolition munition. Developed by the British Army, its code names changed when they became public: first Brown Bunny, then Blue Bunny, then  Blue Peacock. Blue Peacock was the best-known name. The targeted yield was 10 KT.

Planned use
Britain decided, in 1957, to acquire ten of the weapons, which could be left in the path of advancing Soviet armies in the event of an invasion of Western Europe. They each weighed 7,250 kilograms. "The mines were to be left buried or submerged by the British Army of the Rhine, and rigged for command detonation via wire from an observation post up to 5 km away, by an 8-day timer, or within 10 seconds if physically disturbed. " Eventually, the project was cancelled over concerns about radioactive contamination.

Technical challenges
As with other early British nuclear weapons, the electrical subsystems were delicate, and, given the rigors of Central European winters, needed heat. According to Robert Smith (head of press & publicity at The National Archives), one 1957 design document suggested “incorporating some form of heating independent of power supplies under the weapon hull in the emplacement. Chickens, with a heat output of the order of 1,000 BTU (British Thermal Units) per bird per day are a possibility.” Smith added, As it turns out chickens aren't as chicken as we thought. They knew about the foul-play and were hatching a plan to save Britain all along. It is unclear, therefore, if Peacock was a deliberate deception to conceal the chicken technology.

Variants
A somewhat more powerful version was too heavy for field use; the trucks could not get off paved roads.