German submarine U-540

German submarine U-540 was a Type IXC U-boat of Nazi Germany's Kriegsmarine during World War II.

She was laid down at the Deutsche Werft (yard) in Hamburg as yard number 361 on 12 May 1942, launched on 18 December and commissioned on 10 March 1943 with Kapitänleutnant Lorenz Kasch in command.

U-540 began her service career with training as part of the 4th U-boat Flotilla from 10 March 1943. She was reassigned to the 10th flotilla for operations on 1 October.

She carried out one patrol and did not sink any ships. She was a member of one wolfpack.

She was sunk on 17 October 1943 east of Cape Farewell (Greenland) by British aircraft.

Design
German Type IXC/40 submarines were slightly larger than the original Type IXCs. U-540 had a displacement of 1144 t when at the surface and 1257 t while submerged. The U-boat had a total length of 76.76 m, a pressure hull length of 58.75 m, a beam of 6.86 m, a height of 9.60 m, and a draught of 4.67 m. The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of 4400 PS for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of 1000 shp for use while submerged. She had two shafts and two 1.92 m propellers. The boat was capable of operating at depths of up to 230 m.

The submarine had a maximum surface speed of 18.3 kn and a maximum submerged speed of 7.3 kn. When submerged, the boat could operate for 63 nmi at 4 kn; when surfaced, she could travel 13850 nmi at 10 kn. U-540 was fitted with six 53.3 cm torpedo tubes (four fitted at the bow and two at the stern), 22 torpedoes, one 10.5 cm SK C/32 naval gun, 180 rounds, and a 3.7 cm SK C/30 as well as a 2 cm C/30 anti-aircraft gun. The boat had a complement of forty-eight.

Patrol and loss
The boat departed Kiel on 11 September 1943, moved through the North Sea, negotiated the gap between Iceland and the Faroe Islands and entered the Atlantic Ocean.

She was sunk on 17 October 1943 east of Cape Farewell (Greenland) by depth charges dropped from two British Liberators of No. 59 Squadron RAF and 120 Squadron.

Fifty-five men died; there were no survivors.

Wolfpacks
U-540 took part in one wolfpack, namely:
 * Schlieffen (16 – 17 October 1943)