German submarine U-7 (1935)

German submarine U-7 was a Type IIB U-boat of Nazi Germany's Kriegsmarine, based out of Kiel during World War II. It was one of the smaller versions, and was first launched on 29 June 1935 with a crew of 29. Its first commander was Kurt Freiwald. U-7 would have 16 commanders over the course of its service, the last being Günther Loeschcke.

During the war U-7 was responsible for sinking two vessels.

On 18 February 1944, west of Pillau, U-7 sank in what is believed to have been a malfunction during a diving manoeuvre. There were no survivors.

Design
German Type IIB submarines were enlarged versions of the original Type IIs. U-7 had a displacement of 279 t when at the surface and 328 t while submerged. Officially, the standard tonnage was 250 LT, however. The U-boat had a total length of 42.70 m, a pressure hull length of 28.20 m, a beam of 4.08 m, a height of 8.60 m, and a draught of 3.90 m. The submarine was powered by two MWM RS 127 S four-stroke, six-cylinder diesel engines of 700 PS for cruising, two Siemens-Schuckert PG VV 322/36 double-acting electric motors producing a total of 460 PS for use while submerged. She had two shafts and two 0.85 m propellers. The boat was capable of operating at depths of up to 80 - 150 m.

The submarine had a maximum surface speed of 12 kn and a maximum submerged speed of 7 kn. When submerged, the boat could operate for 35 - 42 nmi at 4 kn; when surfaced, she could travel 3800 nmi at 8 kn. U-7 was fitted with three 53.3 cm torpedo tubes at the bow, five torpedoes or up to twelve Type A torpedo mines, and a 2 cm anti-aircraft gun. The boat had a complement of twentyfive.

Service history
U-7 was ordered on 20 July 1934, i.e. in violation of the Versailles Treaty, which denied Germany possession of submarines. The U-boat was not laid down until 11 March 1935, and launched on 29 June 1935, within weeks of the Anglo-German Naval Agreement, which granted Germany parity with the British Empire in submarines.

Commissioned on 18 July 1935 with Kapitänleutnant Kurt Freiwald in command, U-7 mainly served as a training boat except for two brief deployments during the Invasion of Poland in 1939 and Operation Weserübung in 1940.

On 18 February 1944, west of Pillau, U-7 sank in what is believed to have been a malfunction during a diving manoeuvre. There were no survivors.