German submarine U-175 was a Type IXC U-boat of Nazi Germany's Kriegsmarine built for service during World War II. She was laid down on 30 January 1941 at Bremen, and commissioned on 5 December 1941 with Kapitänleutnant Heinrich Bruns in command. After training with the 4th U-boat Flotilla, U-175 was transferred to the 10th U-boat Flotilla for front-line service. Throughout her career, the boat undertook three war patrols during which she sank ten merchant ships amounting to a total of before being sunk by the US Coast Guard cutter on 17 April 1943.
Construction and design
Construction
U-175 was ordered by the Kriegsmarine on 23 December 1939. She was constructed as part of Plan Z, a naval construction program that envisaged the acquisition of 249 U-boats along with numerous surface vessels by 1948, and which was in direct contravention of Germany's obligations under the Anglo-German Naval Agreement. The vessel's keel was laid down in the DeSchiMAG AG Weser shipyard in Bremen on 30 January 1941 at which point it became known by the yard number or designation 1015. Built alongside and , the boat's crew was slowly assembled during construction, they were billeted within a building at the North German Lloyd Shipping Company, also in Bremen. After about nine months of construction U-175 was launched on 2 September 1941.
Design
German Type IXC submarines were slightly larger than the original Type IXBs. U-174 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-174 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.
As part of the improvements of the IXC type over the previous IXBs, U-175 was able to carry an extra 43 tonnes of fuel, giving her a capacity of 208 tonnes. Her power plant was heavier than those in previous models, and in order to accommodate this and balance the boat, the engine room was built directly aft of the control room, as opposed to behind the galley like in other types. The periscope in the control room was also deleted, leaving the boat with just two of the optical devices, both of which were located in the conning tower.
Service history
Working up
U-175 was commissioned into the Kriegsmarine on 5 December 1941 under the command of Kapitänleutnant Heinrich Bruns. Bruns graduated from the 1931 class and had previously commanded a torpedo boat, T3, which had been sunk by British aircraft in September 1940 near Le Havre. After recovering from his wounds, Bruns served on a training ship before transferring to the U-boat service in early 1941. Upon completion of the U-boat captain's course, Bruns served briefly on , where he was confirmed as suitable for command. He was 29 years old upon taking up his post with U-175. British naval intelligence, which tried to maintain personality and psychological profiles on all U-boat commanders, assessed him as "too ambitious and incautious". Nevertheless, he was later described by his crew as a "'humane officer' with more concern for...his men than the niceties of military protocol" who was "strict, but fair" and "dedicated to running an efficient, contented boat".