German submarine U-340

German submarine U-340 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II.

The submarine was laid down on 1 October 1941 at the Nordseewerke yard at Emden, launched on 20 August 1942, and commissioned on 16 October 1942 under the command of Oberleutnant zur See Hans-Joachim Klaus. U-340 served with the 8th U-boat Flotilla, for training and then with the 6th U-boat Flotilla for operational service from 1 May to 2 November 1943.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-340 had a displacement of 769 t when at the surface and 871 t while submerged. She had a total length of 67.10 m, a pressure hull length of 50.50 m, a beam of 6.20 m, a height of 9.60 m, and a draught of 4.74 m. The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2800 to 3200 PS for use while surfaced, two AEG GU 460/8–27 double-acting electric motors producing a total of 750 PS for use while submerged. She had two shafts and two 1.23 m propellers. The boat was capable of operating at depths of up to 230 m.

The submarine had a maximum surface speed of 17.7 kn and a maximum submerged speed of 7.6 kn. When submerged, the boat could operate for 80 nmi at 4 kn; when surfaced, she could travel 8500 nmi at 10 kn. U-340 was fitted with five 53.3 cm torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm SK C/35 naval gun, 220 rounds, and two twin 2 cm C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.

First patrol
U-340 sailed from Kiel on 29 April 1943, and out into the Atlantic to the waters south-east of Cape Farewell, Greenland, before returning to Bordeaux on 31 May, after 33 days at sea with no successes.

Second patrol
U-340's next patrol took her from Bordeaux on 6 July 1943, south to the coast of West Africa. On 25 August she rescued five Luftwaffe airmen off the coast of Spain, and was attacked by an aircraft shortly afterwards, suffering some damage; several men were wounded. She returned to Saint-Nazaire on 2 September.

Third patrol
U-340's third and final patrol began on 17 October 1943, sailing from Saint-Nazaire south to the Strait of Gibraltar. There she was sunk on 2 November 1943, near Tangier at position 35.55°N, -6.61667°W, by depth charges from the sloop HMS Fleetwood (U47), the destroyers HMS Active (H14) and HMS Witherington (D76) and a Liberator bomber of No. 179 Squadron RAF. One of U-340's crew was killed and 48 survived the attack.