German submarine U 1023

Design

German Type VIIC/41 submarines were preceded by the heavier Type VIIC submarines. U-1023 had a displacement of 759 tonnes (747 long tons) when at the surface and 860 tonnes (850 long tons) while submerged. She had a total length of 67.10 m (220 ft 2 in), a pressure hull length of 50.50 m (165 ft 8 in), a beam of 6.20 m (20 ft 4 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.74 m (15 ft 7 in). The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2,800 to 3,200 metric horsepower (2,060 to 2,350 kW; 2,760 to 3,160 shp) for use while surfaced, two Brown, Boveri & Cie GG UB 720/8 double-acting electric motors producing a total of 750 metric horsepower (550 kW; 740 shp) for use while submerged. She had two shafts and two 1.23 m (4 ft) propellers. The boat was capable of operating at depths of up to 230 metres (750 ft).

The submarine had a maximum surface speed of 17.7 knots (32.8 km/h; 20.4 mph) and a maximum submerged speed of 7.6 knots (14.1 km/h; 8.7 mph). When submerged, the boat could operate for 80 nautical miles (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 8,500 nautical miles (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph). U-1023 was fitted with five 53.3 cm (21 in) torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm (3.46 in) SK C/35 naval gun, 220 rounds, and an anti-aircraft gun. The boat had a complement of between forty-four and sixty.

Service history

U-1023 was ordered by the Kriegsmarine on 13 June 1942. She was laid down about one year later at Blohm & Voss, Hamburg on 20 May 1943. Almost a year later, U-1023 was launched from Hamburg on 3 May 1944. She was formally commissioned later that year on 15 July. U-1023 carried 5 × 53.3 cm (21 in) torpedo tubes (4 located in the bow, 1 in the stern) and had one 8.8 cm (3.46 in) deck gun with 220 rounds. She could also carry 14 G7e torpedoes or 26 TMA mines and had a crew of 44–52 men. She was one of the U-boats that used the Schnorchel underwater breathing apparatus.

After her redesignation as a front-line U-boat, U-1023 left port on her first and only patrol. By that time, she had moved from Kiel to her later location in Bergen via a stopover in Horten Naval Base. After leaving on 25 March 1945 for her first patrol, U-1023 intercepted and attacked Riverton, a 7,345 tonnes (7,229 long tons) British steam merchant on 23 April. She was damaged and beached off of St. Ives Bay. Later, on 7 May 1945, the last day of the war in Europe, U-1023 found the 335 ton Norwegian minesweeper NYMS 382, which was sunk with 22 dead.

Fate

Three days later, the ship surrendered at Weymouth, England. After the war she was paraded up the west coast of the UK visiting a number of ports including Plymouth, Brixham, Falmouth, Bristol, Swansea, Liverpool, Holyhead, Manchester, Fleetwood, Belfast, Glasgow, Greenock, Rothsay, Oban. Several hundred thousand visitors were given a tour of the boat during this time. U-1023 was then used in Operation Deadlight and sunk by the Allies.

FLAK weaponry

U-1023 was mounted with a single 3.7 cm Flakzwilling M43U gun on the rare LM 43U mount. The LM 43U mount was the final design of mount used on U-boats and is only known to be installed on U-boats (U-249, U-826, U-977, U-1171, U-1305 and U-1306). The 3.7 cm Flak M42U was the marine version of the 3.7 cm Flak used by the Kriegsmarine on Type VII and Type IX U-boats. U-1023 was mounted with two 2cm Flak C38 in a M 43U Zwilling mount with short folding shield on the upper Wintergarten. The M 43U mount was used on a number of U-boats (U-190, U-250, U-278, U-337, U-475, U-853, U-1058, U-1109, U-1105, U-1165 and U-1306).