On this day in 1943, British submarines attempt to sink the German battleship Tirpitz as it sits in Norwegian waters, as Operation Source gets underway. The Tirpitz was the second largest battleship in the German fleet (after the Bismarck) and a threat to Allied vessel movement through Arctic waters.
In January 1942, Hitler ordered the Germany navy to base the Tirpitz in Norway in order to attack Soviet convoys transporting supplies from Iceland to the U.S.S.R. The Tirpitz also prevented British naval forces from making their way to the Pacific. Winston Churchill summed up the situation this way: "The destruction or even crippling of this ship is the greatest event at the present time.... The whole strategy of the war turns at this period on this ship...."
Attacks had already been made against the Tirpitz. RAF raids were against it in January 1942 failed to hit it. Another raid was made in March; dozens of RAF bombers sought out the Tirpitz, which had been reinforced with cruisers, pocket battleships, and destroyers. All of the British bombers, once again, missed their target.
Sporadic attacks continued to be made against the German battleship, including an attempt in October 1942 to literally drive a two-man craft up to the ship and plant explosives on the Tirpitz's hull. This too failed because of brutal water conditions and an alert German defense. In 1943, the battleship Scharnhorst joined the Tirpitz, creating a threat to Allied shipping that caused all convoys to the Soviet Union to be temporarily halted. Finally, in September, six midget British subs set out to take the Tirpitz down for good. The midgets had to be towed to Norway by conventional subs. Only three of the six midgets made it to their target. This time, they were successful in attaching explosives to the Tirpitz's keel—and did enough damage to put it out of action for six months. Two British commanders and four crewmen were taken captive by the Germans and spent the rest of the war as POWs.
Ironically, the mighty Tirpitz fired its guns only once in aggression during the entire war—against a British coaling station on the island of Spitsbergen.