On the night of 16-17 May 1943, Wing Commander Guy Gibson led 617 Squadron of the Royal Air Force on an audacious bombing raid to destroy three dams in the Ruhr valley, the industrial heartland of Germany. The mission was codenamed Operation 'Chastise'.
The dams were fiercely protected. Torpedo nets in the water stopped underwater attacks and anti-aircraft guns defended them against enemy bombers.
But 617 Squadron had a secret weapon: the 'bouncing bomb'.
The targets
The Möhne dam in Germany's Ruhr valley secured the water supply for much of the surrounding area. Water from its reservoir was also used to generate electricity. It was thought that destruction of this dam and others in the region would cause massive disruption to German war production. Plans for an attack on the dams had first been considered in 1937, but it took until 1942 to develop a weapon capable of destroying the dams - and the aircraft to deliver it.
