Vickers 4,000lb 'Tallboy Small' Demonstration Earthquake Bomb
1943, Stratosphere Chamber, On long term display
This is the only known surviving example of a Vickers ‘Tallboy Small’ 4,000lb demonstration deep penetration bomb designed by Barnes Wallis. In Autumn 1943 Vickers carried out drop tests with inert models of the 4,000lb bomb. Trials were completed by November and revealed instability of the bomb in flight and break up on impact. The instability was cured by adding offset tail fins which caused the bomb to spin. Manganese steel and a chrome molybdenum steel (‘Hykro’), which had a higher yield point, were used in production bomb cases to prevent impact break up.
The precise war-time history of this exhibit is unknown but, sometime after 1945, it was acquired by the Vickers-Armstrongs R&D Department at Brooklands and displayed vertically outside Sir Barnes Wallis’ office in the former motoring Clubhouse. In 1989 it was removed for restoration and display elsewhere in the new