This text offers an account of a key operation of World War II. For much of the war, the powerful German battleship Tirpitz had dominated the Atlantic and was a deadly adversary of the Allied convoys. The Royal Navy had achieved notable successes in sinking the Graf Spee in 1939 and the Bismarck in 1941, but from its base in Norway, Tirpitz effectively blocked the convoy routes to North Russia and threatened the possibility of a destructive breakout into the Atlantic. British midget submarines and Soviet and Royal Navy Fleet Air Arm torpedo bombers all tried to destroy Tirpitz in port, but only succeeded in temporarily immobilizing her. Parallel to these efforts, were those of inventor Dr Barnes Willis (of the bouncing bomb) who strove to perfect a similar bomb for use against Tirpitz by the specially formed No. 618 Squadron RAF. Protracted trials and technical problems dogged the programme and by late 1943, it was deemed to late for success. Meanwhile, the Royal Navy's midget submarine took place and torpedo bombers had some success although by mid-1944 Tirpitz remained a menace. Barnes Willis, however, continued to develop a bomb capable of piercing concrete and armour, resulting in the 12,000lb Tallboy ballistic bomb used by Lancaster bombers in a raid on Tirpitz in September 1944. Following two more attacks, the solitary dinosaur was finally destroyed.