Avro Lancaster B. MK1 Special 'Grand Slam"

In early 1945 the Lancaster was the only aircraft capable of carrying the 22,400lb "Grand Slam" earthquake bomb designed by Barnes Wallis, the largest conventional bomb of WWII. 32 Lancasters of type B.I (Spec) had the bomb bay doors removed to assist loading the massive bomb, and the front and upper turrets were removed and faired over to save as much weight as possible. Air defence was four 0.303in Browning machine guns in the rear turret, later changed to two 0.5in Brownings.
Markings for PD119/YZ-J, 617 Squadron, Woodhall Spa, England April 1945