German submarine U-30 was a Type VIIA U-boat of Nazi Germany's Kriegsmarine that served during World War II.

[1] Like all Type VIIA submarines, U-30 had two MAN 6-cylinder 4-stroke M6V 40/46 diesel engines totalling 2,100–2,310 PS (1,540–1,700 kW; 2,070–2,280 bhp) as well as two Brown, Boveri & Cie GG UB 720/8 electric motors, that produced 750 PS (550 kW; 740 shp) and allowed her to travel at a maximum of 17 knots (31 km/h; 20 mph) while surfaced and 8 knots (15 km/h; 9.2 mph) submerged.

[4] Her active service career began on 3 September 1939, just 12 days after leaving Wilhelmshaven and only 10 hours after Great Britain declared war on Germany, she sank the 13,581 GRT passenger ship SS Athenia about 200 nmi (370 km; 230 mi) west of the Hebrides while she was en route from Liverpool to Montreal in Canada.

[5][6] The Athenia was the first ship sunk in World War II; out of 1,400 passengers, 112 of them, including 28 neutral Americans, died.

[6] They claimed instead that the British had torpedoed their own vessel in an attempt to bring the United States into the war on the side of the Allies.

Dönitz subsequently received orders that Athenia affair was to be kept a "total secret",[7] the High Command of the Navy (OKM) were not to court-martial Lemp as they considered his actions in good faith, and that any other political explanations about the sinking of Athenia were to be handled by the OKM, who would deny any allegations that a German U-boat had sunk the vessel.

[7][8] As a result of the investigation undertaken by the German General Staff following the sinking of Athenia, U-30 remained in port until 9 December 1939, when she was finally allowed to put to sea again for her second war patrol.

It lasted only six days, during which time she travelled up to the southern coast of (then neutral) Norway before returning to Wilhelmshaven on 14 December 1939.

It was near to the west coast of Scotland that U-30 sank her first enemy vessel during her third patrol, the 325 GRT anti-submarine trawler HMS Barbara Robertson, on 28 December.

[10] The fourth patrol that U-30 undertook began on 11 March 1940, when she left Wilhelmshaven for the west coast of Norway in preparation for the invasion of that country.

For a period of 20 days, she traveled northeast along the Norwegian coast in search of any Allied convoys; she did not find any and returned to Wilhelmshaven on 30 March 1940.

She put to sea on 3 April 1940 to support the German invasion of Norway and Denmark (codenamed Operation Weserubung).

Having left Wilhelmshaven on 8 June 1940, she once again entered the North Sea in an attempt to sink any Allied ships in the area.

[16] The eighth and last war patrol that U-30 was to undertake began on 5 August 1940, when she left Lorient for the North Atlantic.

[17] After these successes, however, U-30 once again experienced engine trouble and was forced to end her patrol early, returning to Germany.

[18] Following her eighth patrol, U-30 was retired from front-line service on 15 September 1940 and was assigned to training flotillas in the Baltic for the rest of the war.