Grand Slam

The Bomb, Medium Capacity, 22,000 lb (Grand Slam) was a 22,000 lb (10,000 kg) earthquake bomb used by RAF Bomber Command against German targets towards the end of the Second World War. The bomb was originally called Tallboy Large until the term Tallboy got into the press and the code name was replaced by "Grand Slam". The bomb was similar to a large version of the Tallboy bomb but a new design and closer to the size that its inventor, Barnes Wallis, had envisaged when he developed the idea of an earthquake bomb. It was the largest and most powerful conventional (non-nuclear) aerial bomb used by either side during the war.
Medium Capacity (MC) bombs were designed to remedy the shortcomings of General Purpose (GP) bombs, with a greater blast and casings which were robust enough to confer a considerable capacity to penetrate, especially the Tallboy and Grand Slam. The Grand Slam case was made of a chrome-molybdenum alloy steel, with the charge constituting over 43 per cent of the bomb's weight.
Standard Avro Lancaster bombers could not carry the bomb; Avro built 32 Lancaster B.Mk 1 (Special)s with more powerful Merlin engine variants, a stronger undercarriage, without bomb bay doors and...