I didn't know much about these guys until very recently.
The Lancaster dambuster.
A normal Lancaster was retrofitted with a 8800 pound bomb that would spin backwards at 500 RPM, dropped at extremely low altitude (-100ft) towards the dam wall. Rotational inertia would cause the the munition to bounce for up to 700 yards across the lake and then down to the bottom after it hit the dam wall, before it went >BOOM!<. It was effective, and ingenious, but not super-practical, and required the best and bravest crews.
There was a similar ball-shaped rotational bomb developed alongside this barrel bomb to be fitted to a Mosquito but it was never used.
World War II. The stories will never end.
