U-400

U-400. It was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. Commissioned in late 1943, the vessel conducted a single, unsuccessful war patrol in the Atlantic Ocean. The submarine was ultimately sunk with all hands by Allied forces in late 1944, contributing to the heavy losses sustained by the U-boat Arm in the final years of the conflict.

Design and construction

U-400 was ordered by the Oberkommando der Marine as part of the massive naval expansion program following the outbreak of World War II. Its keel was laid down on 17 October 1942 at the Howaldtswerke-Deutsche Werft (HDW) shipyard in Kiel, a major center for U-boat construction. The vessel belonged to the Type VIIC class, which formed the backbone of the German submarine fleet, renowned for its balance of seaworthiness, armament, and range. Like its sisters, it was designed for operations across the Atlantic Ocean, featuring a pressure hull strong enough for deep diving and equipped with five torpedo tubes. After nearly a year of fitting out, U-400 was launched on 23 September 1943 in a ceremony attended by shipyard workers and naval officials. The boat was formally commissioned into the Kriegsmarine on 28 October 1943 under the command of Kapitänleutnant Horst Creutz, beginning its service with the 5th U-boat Flotilla for training in the Baltic Sea.

Service history

Following intensive training exercises in the Baltic Sea with the 5th U-boat Flotilla, U-400 was declared operational and transferred to the 11th U-boat Flotilla based in Bergen for front-line duties. Its only war patrol began on 16 November 1944 when it departed Horten under the command of Kapitänleutnant Horst Creutz, tasked with joining the wolfpack operations against Allied shipping in the North Atlantic. The strategic situation for the Kriegsmarine was dire, as the Battle of the Atlantic had decisively turned in favor of the Allies due to advancements like Hedgehog and improved intelligence. During its transit, U-400 was directed to patrol areas west of the British Isles, but it failed to encounter any convoys or engage enemy vessels. The patrol was marked by constant evasion of Allied patrols and aircraft, reflecting the overwhelming dominance of the Western Approaches Command and RAF Coastal Command. After a month at sea with no successes to report, the boat was ordered to return to base, highlighting the crippling effectiveness of the Allied anti-submarine warfare campaign led by forces like the Royal Navy and United States Navy.

Fate

While returning from its futile patrol, U-400 was detected and attacked in the Celtic Sea southwest of Ireland. On 17 December 1944, the British frigate HMS *Nyasaland* and the sloop HMS *Amethyst*, operating as part of a Hunter-killer group, made sonar contact with the submerged submarine. The warships, veterans of numerous Atlantic engagements, commenced a sustained depth charge attack. After a series of detonations, a large underwater explosion was observed, followed by debris and oil rising to the surface. No survivors were recovered from U-400, and its entire crew of 50 men, including Kapitänleutnant Horst Creutz, was lost. The sinking was a typical result of the final phase of the U-boat campaign, where German submarines suffered catastrophic losses to Allied countermeasures. The wreck of U-400 was later identified by marine archaeologists, lying at a depth of approximately 100 meters, serving as a war grave and a testament to the fierce naval conflict around the British Isles.

Category:World War II submarines of Germany Category:Type VIIC submarines Category:Maritime incidents in December 1944