Heavy bomber version of the bouncing bomb, was used to destroy the Mohne and Eder dams by Lancasters from the specially recruited and trained 617 Squadron, often known as the Dambusters, under Wing Commander Guy Gibson. In March and April 1945, as the war in Europe was ending, Lancasters dropped Grand Slams and Tallboys on U-boat pens and railway viaducts across north Germany. At Bielefeld more than of railway viaduct was destroyed by Grand Slams creating an earthquake effect, which shook the foundations. The Boeing B-29 Superfortress was a development of the Fortress, but a larger design with four Wright R-3350 Duplex-Cyclone
History of the Royal Air Force war was the strategic bombing campaign against Germany. From 31 May 1942 RAF Bomber Command was able to mount large-scale night raids, sometimes involving up to 1,000 aircraft. From mid-1942 increasing numbers of these aircraft were heavy four-engined bombers such as the Handley-Page Halifax and the Avro Lancaster. Noteworthy raids include Operation Millennium against Cologne, the first 1000-bomber raid; Operation Chastise, the 'Dambusters' raids on targets in the Ruhr Valley; Operation Gomorrah, the destruction of Hamburg; and the 'Battle of Berlin'. The lighter, fast two-engine de Havilland Mosquito fighter-bomber was used for tactical raids like Operation Carthage, a raid on