German submarine U-136 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II.
She was laid down at Vulkan-Vegesackerwerft in Bremen on 2 October 1940 as yard number 15, launched on 5 July 1941 and commissioned on 30 August with Kapitänleutnant Heinrich Zimmermann in command.
Her service career began with the commencement of crew training with the 6th U-boat Flotilla on her commissioning date. She became operational on 1 January 1942, also with the 6th flotilla.
She sank five ships, with a total of and two warships totalling 1,850 tons. She also damaged one ship of .
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-136 had a displacement of 769t when at the surface and 871t while submerged. She had a total length of 67.1m (220.1feet), a pressure hull length of 50.5m (165.7feet), a beam of 6.2m (20.3feet), a height of 9.6m (31.5feet), and a draught of 4.74m (15.55feet). The submarine was powered by two MAN 6-cylinder 4-stroke M6V 40/46 four-stroke, six-cylinder supercharged diesel engines producing a total of NaNPS for use while surfaced, two Brown, Boveri & Cie GG UB 720/8 double-acting electric motors producing a total of 750PS for use while submerged. She had two shafts and two 1.23abbr=onNaNabbr=on propellers. The boat was capable of operating at depths of up to .
The submarine had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . U-136 was fitted with five 53.30NaN0 torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.82NaN2 SK C/35 naval gun, 220 rounds, and an anti-aircraft gun. The boat had a complement of between forty-four and sixty.
Her first patrol was unusual in that it was divided into three parts. Part one saw the boat depart Kiel on 22 January 1942 and arrive at Kristiansand in Norway on the 24th. Part two was from Kristiansand to Bergen, also in Norway. Part three involved the boat crossing the North Sea and negotiating the passage between the Faroe and Shetland Islands into the Atlantic Ocean. While doing so, she sank on 5 February and on the 11th. She also sank on the 17th. She then sailed to St. Nazaire in occupied France, arriving on 1 March.
During U-136s second patrol, the boat damaged Axtell J. Byles off the US North Carolina coast on 19 April 1942 and sank Empire Drum about 280nmi southeast of New York on the 24th. All the crew survived; one of them, the third engineer, was found floating with a part of the ship's cargo tucked under each arm - it was TNT.
The boat's third and last patrol began with her departure from St. Nazaire on 29 June 1942. On 11 July, she was sunk with all hands (45 men), by depth charges from the Free French destroyer Léopard, the British frigate and the British sloop west of Madeira.
U-136 took part in two wolfpacks, namely:
| - | Date | Name | Nationality | Tonnage[1] | Fate[2] |
|---|---|---|---|---|---|
| 5 February 1942 | 925 | Sunk | |||
| 11 February 1942 | Heina |  Norway | 4,028 | Sunk | |
| 11 February 1942 | 925 | Sunk | |||
| 17 February 1942 | Empire Comet |  United Kingdom | 6,914 | Sunk | |
| 19 April 1942 | Axtell J. Byles |  United States | 8,955 | Damaged | |
| 24 April 1942 | Empire Drum | United Kingdom | 7,244 | Sunk | |
| 28 April 1942 | Arundo |  Netherlands | 5,163 | Sunk | |
| 8 May 1942 | Mildred Pauline |  Canada | 300 | Sunk |