The famous dams raid in May 1943 was made possible only by the fusion of cutting-edge technology with the raw courage of a hand-picked squadron of RAF airmen. The incredible bouncing bomb, used to devastating effect by 617 Squadron on the Ruhr dams, was the vanguard of a whole train of technical developments that made this and other precision raids possible. Using the Haynes Manual approach, Iain Murray describes the technology behind the bouncing bomb as well as the heavily modified Lancasters that were used to deliver the weapons.