German submarine U-1 (1935)

German submarine U-1 was the first U-boat (or submarine) built for the German Kriegsmarine following Adolf Hitler's abrogation of the terms of the Treaty of Versailles in 1935, which banned Germany possessing a submarine force.

A Type IIA U-boat, she was built at the Deutsche Werke shipyards in Kiel as 'Werk' 236, her keel being laid on 11 February 1935 amid celebration. She was completed on 29 June 1935 after a very rapid construction, and was manned by crews trained in the Netherlands.

Service history
Her pre-war service was unremarkable, but she did gain a reputation as a poor ship. Her rapid construction, combined with the inadequacy of the technology which was used to create her, made her uncomfortable, leaky and slow. When war came, there were already plans to shelve her and her immediate sisters of the Type II class for use as training boats only.

Despite this however, owing to a shortage of available units she sailed on 29 March 1940 against British shipping operating off Norway, close to the limit of her effective operating range. She failed to find a target, but was sent out again on 4 April, in preparation for Operation Weserübung (the invasion of Norway).

Fate
U-1 sent a brief radio signal on 6 April, giving her position, before she disappeared. The cause of her loss is unknown, but she was scheduled to sail through a minefield laid unknown to the Germans by the British submarine HMS Narwhal (N45) that same day. U-1 may have also been sunk by the British submarine HMS Porpoise (N14), which reported launching a torpedo at an unidentified enemy submarine (subsequently thought to be GS U-3 (1935)), on 16 April following the invasion.

She was the first of over 1,000 U-boats to serve during the Battle of the Atlantic, and one of over 700 to be lost at sea.