German submarine U-154 was a Type IXC U-boat of Nazi Germany's Kriegsmarine built for service during World War II. The keel for this boat was laid down on 21 September 1940 at the DeSchiMAG AG Weser yard in Bremen, Germany as yard number 996. She was launched on 21 April 1941 and commissioned on 2 August under the command of Korvettenkapitän Walther Kölle.
The submarine began her service life with training as part of the 4th U-boat Flotilla; moving on to the 2nd flotilla for operations. She conducted eight patrols, sinking ten ships.
Although it was believed to be sunk by the Colombian Destroyer ARC Caldas during a short encounter near San Andrés Island in 1944, the U-154 escaped without damage. Using spare oil and some damaged torpedo tubes, the Germans were able to fake the oil slick and wreckage.
U-154 was sunk by the US destroyer escorts and northwest of Madeira on 3 July 1944.
German Type IXC submarines were slightly larger than the original Type IXBs. U-154 had a displacement of when at the surface and while submerged. The U-boat had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of for use while submerged. She had two shafts and two 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-154 was fitted with six torpedo tubes (four fitted at the bow and two at the stern), 22 torpedoes, one SK C/32 naval gun, 180 rounds, and a SK C/30 as well as a C/30 anti-aircraft gun. The boat had a complement of forty-eight.
The boat's first patrol began with her departure from Kiel on 7 February 1942. She headed for the Atlantic Ocean west of Ireland via the gap between the Faroe and Shetland Islands. She docked at Lorient in occupied France, on 1 March.
For her second sortie, she sailed to the Caribbean, sinking Como Rico on 4 April 1942, about north of St. Juan, in Puerto Rico. Her success continued with the sinking of Catahoula, Delvalle, Empire Amethyst and Vineland, all near Haiti and the Dominican Republic.
Her third patrol saw her cross the Atlantic once more. She sank Tillie Lykes on 28 June 1942, about south of Santo Domingo in the Dominican Republic and Lalita, using the deck gun, in the Yucatán Channel on 6 July.
One of the boat's victims on this, her fourth patrol, was Nurmahal. She was sunk on 9 November 1942 east of Martinique "in less than thirty seconds." Another was Tower Grange, sunk off Cayenne in French Guiana.
Having made the short trip from Lorient to Brest, the submarine's fifth foray was her longest (109 days) and second most successful. Amongst many others, she attacked Florida. Although the ship had her back broken on 28 May 1943, she was eventually repaired.
She departed on patrol number six on 2 October 1943. U-154 was attacked by an unidentified PBY Catalina flying boat on 3 November; she was also twice attacked on the 22nd. None caused any damage. The boat returned to Lorient on 20 December.
She was then attacked on 13 March 1944, possibly by the US Navy patrol boat north of the Panama Canal; only minor damage was sustained. U-154 was also engaged on 29 March by the Colombian Navy destroyer ARC Caldas. She returned to France, again to Lorient, on 28 April 1944.
U-154 was sunk by the US destroyer escorts and northwest of Madeira on 3 July 1944.
U-154 took part in one wolfpack, namely:
Oblt.z.S. Oskar Kusch, who had commanded the boat in 1943 and the first month of 1944 and successfully attacked three ships, was court-martialled and shot in May 1944, having been reported by his first officer, Ulrich Abel and his chief engineer, Kurt Druschel for (sedition and defeatism). Kusch had removed Hitler's portrait from the boat and had repeatedly called him an idiot and described the Nazis as tapeworms. Ironically Ulrich Abel, who subsequently gained his own command on U-193 was killed before Kusch's murder, when U-193 was sunk in April 1944 on its first patrol under his command. Druschel was killed when U-154 was sunk on 3 July 1944. It was not until the 1990s that Kusch's legal record was wiped clean and a memorial to his memory was erected, Oskar-Kusch-Strasse, a street in Kiel, Germany is named after him.