German submarine U-998

German submarine U-998 was a Type VIIC/41 U-boat of Nazi Germany's Kriegsmarine during World War II.

She was ordered on 14 October 1941, and was laid down on 5 December 1942 at Blohm & Voss, Hamburg, as yard number 198. She was launched on 18 August 1943 and commissioned under the command of Kapitänleutnant Hans Fiedler on 7 October 1943.

Design
German Type VIIC/41 submarines were preceded by the heavier Type VIIC submarines. U-998 had a displacement of 769 t when at the surface and 871 t while submerged. She had a total length of 67.10 m, a pressure hull length of 50.50 m, an overall beam of 6.20 m, a height of 9.60 m, and a draught of 4.74 m. The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2800 to 3200 PS for use while surfaced, two BBC GG UB 720/8 double-acting electric motors producing a total of 750 PS for use while submerged. She had two shafts and two 1.23 m propellers. The boat was capable of operating at depths of up to 230 m.

The submarine had a maximum surface speed of 17.7 kn and a maximum submerged speed of 7.6 kn. When submerged, the boat could operate for 80 nmi at 4 kn; when surfaced, she could travel 8500 nmi at 10 kn. U-998 was fitted with five 53.3 cm torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm SK C/35 naval gun, 220 rounds, and an anti-aircraft gun. The boat had a complement of between forty-four and fifty-two.

Service history
U-998 had been fitted out in May 1944 with a Schnorchel underwater-breathing apparatus.

Departing Kiel on 12 June 1944, U-998 left on her first, and only, war patrol. Five days into her patrol U-998 was located on 16 June 1944, west of Bergen, by two Norwegian Mosquito FB Mk XVIII aircraft from 333 Sqdn RAF, piloted by Erling U. Johansen and Lauritz Humlen. They were able to hit the boat with 57mm cannon fire and depth charges which caused severe damage to U-998. She was forced to return to Bergen, Norway, where she was removed from active service due to the damage from the attack. U-998 would be cannibalized for spare parts until being broken up later in 1944.