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
Wing leader it", though he had to override his intelligence officer's fear that it made him an attractive target for the enemy. Members of other Commonwealth air forces who led RAF wings included New Zealander Al Deere at Biggin Hill in 1943, and Canadian Howard Blatchford at RAF Coltishall, also in 1943. RAF wing leaders in the Mediterranean and Middle East theatre included wing commanders Ian Gleed and "Cocky" Dundas, who led No. 244 Wing in North Africa in 1943 and in Italy in 1944, respectively. The Royal Navy also employed wing leaders—generally lieutenant commanders or majors in the Royal Marines—to control