German Type IXC/40 submarines were slightly larger than the original Type IXCs. U-866 had a displacement of 1,144 tonnes (1,126 long tons) when at the surface and 1,257 tonnes (1,237 long tons) while submerged.[1] The U-boat had a total length of 76.76 m (251 ft 10 in), a pressure hull length of 58.75 m (192 ft 9 in), a beam of 6.86 m (22 ft 6 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.67 m (15 ft 4 in). The submarine was powered by two MAN M 9 V 40/46 supercharged four-stroke, nine-cylinder diesel engines producing a total of 4,400 metric horsepower (3,240 kW; 4,340 shp) for use while surfaced, two Siemens-Schuckert 2 GU 345/34 double-acting electric motors producing a total of 1,000 shaft horsepower (1,010 PS; 750 kW) for use while submerged. She had two shafts and two 1.92 m (6 ft) propellers. The boat was capable of operating at depths of up to 230 metres (750 ft).[1]
The submarine had a maximum surface speed of 18.3 knots (33.9 km/h; 21.1 mph) and a maximum submerged speed of 7.3 knots (13.5 km/h; 8.4 mph).[1] When submerged, the boat could operate for 63 nautical miles (117 km; 72 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 13,850 nautical miles (25,650 km; 15,940 mi) at 10 knots (19 km/h; 12 mph). U-866 was fitted with six 53.3 cm (21 in) torpedo tubes (four fitted at the bow and two at the stern), 22 torpedoes, one 10.5 cm (4.13 in) SK C/32 naval gun, 180 rounds, and a 3.7 cm (1.5 in) Flak M42 as well as two twin 2 cm (0.79 in) C/30 anti-aircraft guns. The boat had a complement of forty-eight.[1]
Her commander from 17 November 1943 until December 1944 was Korvettenkapitän Walter Pommerehne, followed by Oberleutnant zur See Peter Rogowsky, who commanded her from December 1944 until 18 March 1945.[2]
While under command of Rogowsky, on 18 March, USS Lowe acquired U-866onsonar and commenced a hedgehog attack. This attack missed the U-boat, which then settled on the ocean floor, attempting to hide from the attacking surface ships. Unfortunately for the U-boat, the seabed in the area was ideal for the surface ship's sonar and USS Lowe, USS Menges, USS Mosley, and USS Pride, all destroyer escorts, continued to attack with depth charges, until the U-boat was judged destroyed.[3][4]
She did not sink or damage any ships while on patrol.
Busch, Rainer; Röll, Hans-Joachim (1999). German U-boat commanders of World War II : a biographical dictionary. Translated by Brooks, Geoffrey. London, Annapolis, Md: Greenhill Books, Naval Institute Press. ISBN1-55750-186-6.
Nazi Germany
