617 Squadron RAF was formed in March 1943 to attack the Mohne and Sorpe dams, which provided water to the industrial German Ruhr region, and the Eder, which helped keep canals at navigable depth. A special bomb was developed for the mission by Barnes Wallis. Dropped from low level, it bounced on the water before sliding down the dam wall. On the night of May 16-17, the Mohne and Eder dams were both breached, but although loss of life and industrial dislocation were considerable, the damage was short-lived. Above, Wing Commander Guy Gibson, commander of 617 Squadron, is seen boarding his Lancaster. Eight of the nineteen bombers were lost.
The Barnes Wallis 9,250 Ib (4,195 kg) bouncing bomb slung below a British Lancaster bomber.
The breached Mohne dam four hours after the raid.
Guy Gibson, photographed near RAF Scampton on 22 July 1943. Awarded the Victoria Cross, Britain's highest award for military valour, Gibson was killed the following year at the age of 26.