The Type VII U-boat (Anatomy of the Ship, Repost)

At 21 minutes to eight in the evening of 3 September 1939, the SS Athenia, outward bound from Liverpool to Montreal with 1400 passengers, was struck by a torpedo. This was the first attack in the Second World War to be made by the German Navy, and the torpedo was fired by U30, a Type VII U-boat, commissioned in 1936. On 10 July 1945, the British steam fishing boat Kned was sunk by mine off Lizard Head, in a minefield laid in August 1944 by U 218, a VIID U-boat, commissioned in 1942. Thus the German naval war began and ended in submarine action.
Despite the operations carried out by the more glamorous surface ships, such as Bismarck, GrafSpee, Scharnhorst and Tirpitz, the major effort of this war was made by the Submarine Arm, which began hostilities with 57 boats, of which just 18 were Type VIIs. At that time (September 1939) neither side had an inkling of what effect these boats would have as hostilities continued for five years and nine months, although Britain had instituted convoy sailing as early as August that year. Admiral Raeder, Commander-in-Chief of the German Navy, and Admiral Donitz, Commander of the Submarine Arm, were agreed at the time that the German Navy could contribute little to the war apart from showing that its men knew 'how to die gallantly'.