A line of three bomb trailers, each holding one 12,000 pound Tallboy bomb, which are waiting in a ...

A line of three bomb trailers, each holding one 12,000 pound Tallboy bomb, which are waiting in a bomb dump at 9 Squadron, RAF. The Tallboy was designed by Dr Barnes Wallis as a heavy cased, deep penetration bomb that attained the speed of sound during descent. It was equipped with angled fins which spun the bomb and a delayed action fuse allowed the bomb to penetrate deeply into the ground before exploding, thus causing massive shock waves that would shake down nearby structures such as bridges and railway tunnels. It was also very effective at penetrating the thick concrete covering U boat pens and armoured steel plate. Tallboys were 6.35 metres (21 feet) in length, .95 metres (3 feet 2 inches) in diameter and carried 2,358 kilograms (5,200 pounds) of Torpex explosive. These types of bombs were carried by converted Lancaster bombers of 9 and 617 Squadrons, RAF, and were used to attack the German battleship Tirpitz. Three raids using Tallboy bombs were made against the Tirpitz in 1944 (September, October and November). In the last raid on 12 November 1944, Tirpitz was struck by three Tallboys, which caused massive damage and capsized the battleship, killing nearly 1,000 German sailors.