German submarine U-123 was a Type IXB U-boat of the Kriegsmarine, constructed at the AG Weser yard in Bremen with yard number 955. Laid down on 15 April 1939, she was launched on 2 March 1940 and commissioned on 30 May 1940 under the command of Kapitänleutnant Karl-Heinz Moehle. The vessel measured 76.50 meters in length overall, with a pressure hull length of 58.75 meters, a beam of 6.76 meters, and a height of 9.60 meters. Her displacement was 1,051 tonnes surfaced and 1,178 tonnes submerged. Propelled by two MAN diesel engines producing 4,400 horsepower for surface travel and Siemens-Schuckert electric motors generating 1,000 horsepower submerged, U-123 could reach speeds of 18.2 knots on the surface and 7.3 knots underwater. She had a maximum operational depth of 230 meters. U-123 was armed with six 53.3 cm torpedo tubes (four at the bow, two at the stern), carrying a total of 22 torpedoes, and was equipped with a 10.5 cm deck gun, a 3.7 cm anti-aircraft gun, and a 2 cm AA gun. Her complement was 48 crew members. Throughout her wartime service, U-123 conducted 12 patrols, sinking 45 ships totaling 223,367 GRT and damaging six others. Notable early successes included sinking multiple merchant ships off Ireland and the Atlantic, such as Shekatika, Grootekerk, Venezuela, and the neutral Swedish vessels SS Anten, MV Korsholm, SS Nanking, and MV Venezuela. She participated in Operation Paukenschlag ("Second Happy Time"), attacking Allied shipping along the US East Coast, including near New York, and sinking ships such as Cyclops, Norness, Coimbra, and others, often employing torpedoes and deck guns. Her operational history featured notable engagements, including damaging the armed merchant cruiser HMS Aurania, and sinking the U.S. Q-ship USS Atik after an intense battle. She also sank a Spanish-registered neutral vessel, Castillo Montealegre, in April 1943, an incident marked by controversial conduct. U-123's later patrols involved attacks along the West African coast, sinking ships like Hill-class naval trawler HMS Inkpen and the British submarine HMS P-615. She was ultimately scuttled at Lorient on 19 August 1944, after being decommissioned on 17 June 1944. Post-war, she was raised by the French in 1945 and converted into the French submarine Blaison (Q165), remaining in service until her decommissioning on 18 August 1959. U-123 remains a significant example of the Type IXB submarines and their role in Atlantic naval warfare during WWII.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.