SM UC-55

History
German Empire
NameUC-55
Ordered12 January 1916[1]
BuilderKaiserliche Werft, Danzig[2]
Yard number37[1]
Laid down25 February 1916[1]
Launched2 August 1916[1]
Commissioned15 November 1916[1]
FateSunk off Shetland Islands, 29 September 1917
General characteristics [3]
Class and typeType UC II submarine
Displacement
  • 415 t (408 long tons), surfaced
  • 498 t (490 long tons), submerged
Length
Beam
  • 5.22 m (17 ft 2 in) o/a
  • 3.65 m (12 ft) pressure hull
Draught3.61 m (11 ft 10 in)
Propulsion
Speed
  • 11.6 knots (21.5 km/h; 13.3 mph), surfaced
  • 7.3 knots (13.5 km/h; 8.4 mph), submerged
Range
  • 8,660–9,450 nmi (16,040–17,500 km; 9,970–10,870 mi) at 7 knots (13 km/h; 8.1 mph) surfaced
  • 52 nmi (96 km; 60 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth50 m (160 ft)
Complement26
Armament
Notes30-second diving time
Service record
Part of:
  • I Flotilla
  • 15 February – 29 September 1917
Commanders:
  • Kptlt. Karl Neureuther[4]
  • 15 November 1916 – 11 May 1917
  • Oblt.z.S. Theodor Schultz[5]
  • 12 May – 27 June 1917
  • Oblt.z.S. Horst Rühle von Lilienstern[6]
  • 28 June – 29 September 1917
Operations: 6 patrols
Victories:
  • 9 merchant ships sunk
    (12,988 GRT)
  • 2 merchant ships damaged
    (5,740 GRT)
  • 1 warship damaged
    (440 tons)

SM UC-55[Note 1] was a German Type UC II minelaying submarine or U-boat in the German Imperial Navy (German: Kaiserliche Marine) during World War I. The U-boat was ordered on 12 January 1916, laid down on 25 February 1916, and was launched on 2 August 1916. She was commissioned into the German Imperial Navy on 15 November 1916 as SM UC-55.

Design

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A Type UC II submarine, UC-55 had a displacement of 415 tonnes (408 long tons) when at the surface and 498 tonnes (490 long tons) while submerged. She had a length overall of 50.52 m (165 ft 9 in), a beam of 5.22 m (17 ft 2 in), and a draught of 3.61 m (11 ft 10 in). The submarine was powered by two six-cylinder four-stroke diesel engines each producing 290–300 metric horsepower (210–220 kW; 290–300 shp) (a total of 580–600 metric horsepower (430–440 kW; 570–590 shp)), two electric motors producing 620 metric horsepower (460 kW; 610 shp), and two propeller shafts. She had a dive time of 48 seconds and was capable of operating at a depth of 50 metres (160 ft).[3]

The submarine had a maximum surface speed of 11.6 knots (21.5 km/h; 13.3 mph) and a submerged speed of 7.3 knots (13.5 km/h; 8.4 mph). When submerged, she could operate for 52 nautical miles (96 km; 60 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 8,660 to 9,450 nautical miles (16,040 to 17,500 km; 9,970 to 10,870 mi) at 7 knots (13 km/h; 8.1 mph). UC-55 was fitted with six 100 centimetres (39 in) mine tubes, eighteen UC 200 mines, three 50 centimetres (20 in) torpedo tubes (one on the stern and two on the bow), seven torpedoes, and one 8.8 cm (3.5 in) Uk L/30 deck gun. Her complement was twenty-six crew members.[3]

Service

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In 6 patrols UC-55 was credited with sinking 9 ships, either by torpedo or by mines laid.

Loss

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UC-55 sailed from Heligoland on 25 September 1917 to lay mines in the Lerwick Channel, the southern approach to the port of Lerwick in the Shetland Islands. On 29 September, just as she started dropping her mines, she suffered a loss of trim which resulted in her diving beyond her rated maximum dive depth. This in turn resulted in the forward compartment flooding, the batteries failing, and chlorine gas developing. She was forced to surface to ventilate the boat, but when she surfaced, the rudder refused to answer the helm due to the lack of battery power. Her captain then gave orders to destroy secret documents and codebooks and set scuttling charges in the mine room and engine room. While the charges were being placed she was sighted by the armed trawler Moravia and the destroyers HMS Tirade and HMS Sylvia.[7]

A 12-pdr shell from the Sylvia hit the submarine's conning tower, killing her commander, Horst Ruhle von Lilienstern, and a second shell hit the hull and she began to sink, after which two depth charges were dropped right beside the UC-55, resulting in the U-boat blowing up. The Moravia then closed with the wreck, fired two more shots into her, and dropped a final depth charge. Of the submarine's crew, 17 were taken prisoner, and 10 were killed.[8]

Location

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The wreck of UC-55 was discovered by side scan sonar lying on its keel on 3 July 1985, at a depth of 105 m (344 ft) at 60°3′13″N 0°57′57″W / 60.05361°N 0.96583°W / 60.05361; -0.96583. The submarine's remains were noted to be approximately 5.60 m (18.4 ft) high and 50 m (160 ft) long.[9]

On Friday 21 July 2023 the wreck was confirmed to be that of the UC-55 by the first divers to visit site.[10]

Summary of raiding history

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Date Name Nationality Tonnage[Note 2] Fate[11]
9 March 1917 HMS Albacore  Royal Navy 440 Damaged
19 April 1917 Bethlehem  United Kingdom 379 Sunk
21 April 1917 Gerda  Norway 979 Sunk
28 May 1917 Asters  Norway 1,531 Sunk
29 May 1917 Clan Murray  United Kingdom 4,835 Sunk
30 May 1917 Fernley  United Kingdom 3,820 Damaged
4 June 1917 Clara  Norway 923 Sunk
8 July 1917 Spekulation  Sweden 291 Sunk
10 July 1917 Flamma  United Kingdom 1,920 Damaged
12 July 1917 Balzac  Norway 1,720 Sunk
13 July 1917 Lai  Norway 509 Sunk
19 August 1917 Rosario  United Kingdom 1,821 Sunk

References

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Notes

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  1. ^ "SM" stands for "Seiner Majestät" (English: His Majesty's) and combined with the U for Unterseeboot would be translated as His Majesty's Submarine.
  2. ^ Tonnages are in gross register tons

Citations

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  1. ^ a b c d e Helgason, Guðmundur. "WWI U-boats: UC 55". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 23 February 2009.
  2. ^ Tarrant, p. 173.
  3. ^ a b c Gröner 1991, pp. 31–32.
  4. ^ Helgason, Guðmundur. "WWI U-boat commanders: Karl Neureuther". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 1 March 2015.
  5. ^ Helgason, Guðmundur. "WWI U-boat commanders: Theodor Schultz". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 1 March 2015.
  6. ^ Helgason, Guðmundur. "WWI U-boat commanders: Horst Rühle von Lilienstern". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 1 March 2015.
  7. ^ Messimer, Dwight R. (2002). Verschollen: World War I U-boat losses. Naval Institute Press. pp. 295–296. ISBN 1-55750-475-X.
  8. ^ Baird, R.N. (2003). Shipwrecks of the North of Scotland. Birlinn Ltd. pp. 286–287. ISBN 1-84158-233-6.
  9. ^ Historic Environment Scotland. "Uc-55 [possibly]: North Sea (102953)". Canmore.
  10. ^ "German WW1 U-boat found off the coast of Shetland". BBC News. 25 July 2023. Retrieved 25 July 2023.
  11. ^ Helgason, Guðmundur. "Ships hit by UC 55". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 1 March 2015.

Bibliography

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60°2′N 1°2′E / 60.033°N 1.033°E / 60.033; 1.033