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
John Verdun Newton Force. He was posted to the United Kingdom for operational training with RAF Bomber Command. For several months, Newton trained for night bombing with four-engined heavy bombers at No. 11 OTU (RAF Oakley, Buckinghamshire). In late October 1943, Newton was promoted to Flight Lieutenant and posted to No. 90 Squadron RAF, at RAF Tuddenham in Suffolk. He captained Short Stirlings during raids on Germany, including raids on Kassel, Frankfurt and Bremen. His commanding officer at 90 Sqn, Wing Commander J. H. Giles, described Newton as: "An above average Officer who is an excellent leader of men." In a newspaper interview