Avro Lancaster B.III Special (Type 464 Provisioning)
The Dambusters' Lancaster — no bomb doors, no mid-upper turret, and a spinning 'Upkeep' mine slung underneath · First flight 1943 · In service 1943
To carry Barnes Wallis's "Upkeep" bouncing mine, 23 Lancaster B.IIIs were converted at Avro's Woodford works, with crews working day and night. The bomb-bay doors were removed and replaced by Vickers-built struts that held the drum-shaped mine crosswise, and a hydraulic motor — driven by the pump that had served the deleted mid-upper turret — gave it backspin before release. Two lamps, one in the bomb bay and one in the nose, threw beams that met on the water at exactly the right release height.
The aircraft were flown by No. 617 Squadron, formed less than two months before the raid. On the night of 16–17 May 1943 nineteen Type 464s flew Operation Chastise at very low level against the Möhne, Eder, Sorpe and Ennepe dams; the Möhne and Eder were breached. Eight aircraft were lost and 53 of the 133 aircrew who took part were killed.
Wing Commander Guy Gibson, who led the raid in ED932 "AJ-G", received the Victoria Cross. The operation became the subject of a best-selling book and the 1955 film "The Dam Busters", and 617 Squadron has carried the "Dambusters" name ever since.
