In 1943, the RAF 617 Squadron, led by Wing Commander Guy Gibson, used Derwent Dam to practice low level flying in preparation for the daring Dam Buster raids on the Ruhr Valley Dams in Germany.
They had to practice flying Lancaster bombers at night to a height of only 60 feet above the water. To do this they had to develop a special altimeter, which was made from two spotlights that were put onto the nose and tail of the Lancaster.
The spotlights were angled so that the beams converged at exactly 60 feet below the aircraft.
A special bomb was developed for the raids, known as the 'Bouncing Bomb'. It was developed by Barnes Wallace and was designed to skim or ‘bounce’ across the water, rather like a pebble, before sinking and exploding next to the Dams.
The Upper Derwent Valley is still used today by the RAF for low flying practice.
Photos by Peter de Wolf
