I worked on numerous meaningful weapon systems for DOD. (Be very, very nice to me - I know how to target ICBMs.) I also worked on some real "what the f..k were they thinking" devices that bring to mind the British Panjandrum. While the thermonuclear hand grenade (think about it) never got very far there was one that reached my desk for a design assessment...
During the Vietnam war there was a need to survey troop movements along the Ho Chi Minh trail. Some genius came up with a design for the "hopping rock". Concealed in a fiberglass shell that looked like a rock was a rotary platform that held a vertical periscope affair that could be extended to allow a tiny video camera to view the area surrounding the rock. Attached to the rotor mechanism at a 45 degree angle was an arm with a sliding weight. A motor could haul the weight down to compress a strong spring. When released, the weight would cause the entire "rock" to hop in whatever direction the camera was last pointed.
The idea was to air drop these in quantity around the trail. They would then be "hopped" into suitable surveillance positions where they could watch the trail for troop movements.
When I wrote my assessment, I wrote something like this...
While the device seems eminently impractical for its intended purpose, it has great potential as a psychological terror weapon. Think about it. This poor Viet Cong soldier has been marching for days with little more to eat than fish heads and cold rice. Exhausted, he sits on a rock to rest for a while, whereupon the rock gooses him and then hops off into the jungle! He wouldn't be fit for combat for weeks to come.
