The Ruhr valley has long served as a primary base of heavy industry for the German nation. In World War II, for example, the region processed millions of tons of raw materials to make the steel used to conquer its neighbors.

The area teemed with factories running round the clock, along with a canal and rail system providing efficient transport to receiving docks. And all around, farmers plied the thousands of acres of land that kept the soldiers and citizens of the Third Reich from going hungry.

And nearby, watching at different points in the valley, standing like majestic monuments to man’s efficiency, laid the sources that made it all possible.

They provided the electricity to keep the machinery running without end, and the water to quench the thirst of the workers, as well as millions of others who depended upon them to carry out their livelihoods. They were, of course, the cluster of dams that controlled the flow of the many rivers which coursed throughout the valley, and whose presence weighed heavy on the minds of British war planners. Such structures were viewed as strategic targets at the top of the list to be destroyed…if they could.

The British war planners knew they had to destroy these dams, but, with no weapons system accurate enough to do the job, the idea remained in limbo even after the war passed through its second and third years. By this point Germany was being bombed, yet the dams stood defiant simply because no one put forth a plan worthy enough to attack them with any effect.

That is, until a gifted British aircraft designer named Barnes Wallis began studying the issue, and became convinced he could find a way to destroy them.

Sir Barnes Wallis

Over the next several months, this man, designer of the Vickers Wellington medium bomber used in the early raids against Germany, came up with several unorthodox methods to test his theories. The end result was one of the most unusual, yet brilliant, creations in the history of warfare – a bomb that skipped across water as effortlessly as a stone, yet once contacting its target held on to it until it sunk to a predetermined depth and exploded.