British Forces

Grand Slam earthquake bomb.

This is the later, and heavier, version of the British "Tallboy" bomb (22,000 pounds, as compared with 12,000 pounds for the "Tallboy" which was used against V-3 installations and the "Tirpitz"). Both were the result of a concept developed by Barnes Wallace (designer of the Wellington Bomber and the Dam Busters' "bouncing bomb"), and manufactured by Vickers of Sheffield. Both types were carried as single bombs by Lancaster heavy bombers. As a late arrival on the scene, use of the "Grand Slam" was limited - only about 40 were dropped, sometimes in conjunction with "Tallboys". The results were mixed - but devastating, where accurate strikes were effected. Best regards, JR.