German submarine U-240

German submarine U-240 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 14 May 1942 at the Friedrich Krupp Germaniawerft yard at Kiel as yard number 670, launched on 18 February 1943 and commissioned on 3 April 1943 under the command of Oberleutnant zur See Günther Link.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-240 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-240 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.

Service history
After training with the 5th U-boat Flotilla at Kiel, U-240 was transferred to the 9th U-boat Flotilla for front-line service on 1 February 1944.

She sailed from Kiel to Kristiansand in Norway, on 27 to 28 March 1944, departing from there on her first combat patrol on 13 May.

The U-boat was listed as missing in the North Sea west of Norway from 15 May 1944. No definite explanation exists for her loss, but Sunderland JM667/V of No. 330 Norwegian Squadron (RAF Coastal Command) attacked and sank an unidentified U-boat in that area on 16 May. This is believed to be U-240.

Previously recorded fate
U-240 was originally thought to have been sunk west of Norway by depth charges dropped by a Norwegian Short Sunderland flying boat of No. 330 Squadron RAF. The attack was against GS U-668. No damage was caused.