The bouncing bomb was created by British engineer Sir Barnes Wallis, in order to destroy numerous dams in the Ruhr valley, Germany. The Ruhr valley was one of the dominant industrial areas of Germany, with arms, vehicles and raw materials constantly feeding the Nazi war machine. If the dams were breached, the production potential of the area would be significantly reduced.
The bomb’s design was simple yet complex. It consisted of a cylindrical drum housing almost 3,000kg (6,614lbs) of high explosives, which would be detonated once at the base of a dam. Hydrostatic pistons – as used in depth charges – caused massive structural instability from the resultant explosion and shock waves. Generating the explosion, however, was the simple part of the problem; the real challenge was getting the bomb into position.
Multiple torpedo nets, large steel-linked sheets that formed underwater barriers, protected the dams of the Ruhr. These would snag any incoming underwater explosives and prevent any explosion near the base. Wallis’s bomb, however, was designed to skim across the surface of the water, effectively jumping the nets until it made contact with the dam.
To achieve this, the bomb – apart from having a cylindrical shape – needed to be dropped at a specific height and speed, as well as having a preloaded backspin.
Wallis’s bombs were used on the 16 May 1943 in Operation Chastise, in which 19 bombing aircraft and 113 attack fighters descended on the Ruhr valley. Two major dams were breached, causing massive flooding and loss of life. These successes came at a cost, however, with eight of the bombing aircraft shot down along with 53 of the fighter planes.