SM U-23 (Germany)

History
German Empire
Name	U-23
Ordered	18 March 1911
Builder	Friedrich Krupp Germaniawerft, Kiel
Cost	2,808,000 Goldmark
Yard number	177
Laid down	21 December 1911
Launched	12 April 1913
Commissioned	11 September 1913
Fate	20 July 1915 - torpedoed and sunk off Fair Isle, Scotland, by HMS C27
General characteristics Ocean-going diesel submarine
Class and type	German Type U 23 submarine
Displacement	669 t (658 long tons) surfaced; 864 t (850 long tons) submerged;
Length	64.70 m (212.3 ft)
Beam	6.32 m (20 ft 9 in)
Draught	3.45 m (11 ft 4 in)
Propulsion	2 shafts; 2 × Germania 6-cylinder two stroke diesel motors with 1,800 PS (1,320 kW; 1,780 shp); 2 × SSW double Motordynamos with 1,200 PS (880 kW; 1,180 shp); 450rpm surfaced; 330 rpm submerged;
Speed	16.7 knots (30.9 km/h; 19.2 mph) surfaced; 10.3 knots (19.1 km/h; 11.9 mph) submerged;
Range	9,910 nmi (18,350 km; 11,400 mi) at 8 knots (15 km/h; 9.2 mph) surfaced; 85 nmi (157 km; 98 mi) at 5 knots (9.3 km/h; 5.8 mph) submerged;
Test depth	about 50 m (160 ft)
Boats & landing ; craft carried	1 dinghy
Complement	4 officers, 31 men
Armament	4 × 50 cm (19.7 in) torpedo tubes (2 each bow and stern); 6 torpedoes; 1 × 8.8 cm (3.5 in) SK L/30 gun;
Service record
Part of:	IV Flotilla; 1 August 1914 - Unknown end; III Flotilla; Unknown start – 20 July 1915;
Commanders:	Kptlt. Erwin Weisbach; 1 August – 25 November 1914; Kptlt. Hans Adam; 26 November – 17 December 1914; Kptlt. Egewolf Freiherr von Berckheim; 18 December 1914 – 12 January 1915; Kptlt. Hans Schultheß; 13 January – 20 July 1915;
Operations:	3 patrols
Victories:	7 merchant ships sunk; (8,822 GRT)

SM U-23^{[Note 1]} was one of the 329 U-boats serving in the Imperial German Navy in World War I.

U-23 was engaged in the naval warfare and took part in the First Battle of the Atlantic.

U-23 served on three war patrols, sinking a total of seven ships for 8,822 gross register tons (GRT). She was baited by the Q ship Princess Louise and torpedoed by HMS C27 at 58°55′N 0°14′E / 58.917°N 0.233°E / 58.917; 0.233, off Fair Isle, in Shetland, Scotland. Twenty four men died and 10 survived.

Summary of raiding history

Date	Name	Nationality	Tonnage^{[Note 2]}	Fate^[5]
13 March 1915	Invergyle	United Kingdom	1,794	Sunk
15 March 1915	Fingal	United Kingdom	1,562	Sunk
15 May 1915	Martha	Denmark	1,182	Sunk
19 May 1915	Chrysolite	United Kingdom	222	Sunk
19 May 1915	Crimond	United Kingdom	173	Sunk
19 May 1915	Lucerne	United Kingdom	154	Sunk
22 May 1915	Minerva	Norway	3,735	Sunk

References

Notes

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

Citations

^ Helgason, Guðmundur. "WWI U-boat commanders: Erwin Weisbach". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 16 March 2015.
^ Helgason, Guðmundur. "WWI U-boat commanders: Hans Adam (Pour le Mérite)". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 16 March 2015.
^ Helgason, Guðmundur. "WWI U-boat commanders: Egewolf Freiherr von Berckheim (Royal House Order of Hohenzollern)". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 16 March 2015.
^ Helgason, Guðmundur. "WWI U-boat commanders: Hans Schultheß". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 16 March 2015.
^ Helgason, Guðmundur. "Ships hit by U 23". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 16 March 2015.

Bibliography

Gröner, Erich; Jung, Dieter; Maass, Martin (1991). U-boats and Mine Warfare Vessels. German Warships 1815–1945. Vol. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN 0-85177-593-4.

[5] "SM" stands for "Seiner Majestät" (English: His Majesty's) and combined with the U for Unterseeboot would be translated as His Majesty's Submarine.

[tonnage-6] Tonnages are in gross register tons

[1] Helgason, Guðmundur. "WWI U-boat commanders: Erwin Weisbach". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 16 March 2015.

[2] Helgason, Guðmundur. "WWI U-boat commanders: Hans Adam (Pour le Mérite)". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 16 March 2015.

[3] Helgason, Guðmundur. "WWI U-boat commanders: Egewolf Freiherr von Berckheim (Royal House Order of Hohenzollern)". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 16 March 2015.

[4] Helgason, Guðmundur. "WWI U-boat commanders: Hans Schultheß". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 16 March 2015.

[7] Helgason, Guðmundur. "Ships hit by U 23". German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved 16 March 2015.

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v t e Shipwrecks and maritime incidents in July 1915
Shipwrecks	7 Jul: Amalfi, Ellesmere 8 Jul: Marion Lightbody 11 Jul: SMS Königsberg 18 Jul: Giuseppe Garibaldi 20 Jul: SM U-23 24 Jul: Eastland, SM U-36 26 Jul: Cimba, Mariotte 28 Jul: Trondhjemsfjord 30 Jul: Iberian
Other incidents	19 Jul: USS Oklahoma Unknown date: HMT Boorara, Kléber
1914 1915 1916 June 1915 August 1915