U-9 ready for patrol.
History
German Empire
Name	U-9
Ordered	15 July 1908
Builder	Kaiserliche Werft,Danzig
Cost	2,140,000Goldmark
Yard number	4
Launched	22 February 1910
Commissioned	18 April 1910
Fate	Surrendered 26 November 1918. Broken up atMorecambe in 1919.
General characteristics
Class and type	German Type U 9 submarine
Displacement	493tonnes (485long tons) surfaced 611 tonnes (601 long tons) submerged
Length	57.38 m (188 ft 3 in) (o/a) 48 m (157 ft 6 in) (pressure hull)
Beam	6 m (19 ft 8 in) (o/a) 3.65 m (12 ft) (pressure hull)
Height	7.05 m (23 ft 2 in)
Draught	3.13 m (10 ft 3 in)
Installed power	2 ×Körting 6-cylinder and 2 × Körting 8-cylinder two strokeparaffin motors with a total of 1,000 PS (740 kW; 990 shp) 2 ×SSWelectric motors with 1,160 PS (850 kW; 1,140 shp) 550 rpm surfaced 460 rpm submerged
Propulsion	2 shafts 2 × 1.45 m (4 ft 9 in)propellers
Speed	14.2 knots (26.3 km/h; 16.3 mph) surfaced 8.1 knots (15.0 km/h; 9.3 mph) submerged
Range	1,800 nmi (3,300 km; 2,100 mi) at 14 knots (26 km/h; 16 mph) 80 nmi (150 km; 92 mi) at 5 knots (9.3 km/h; 5.8 mph)
Test depth	50 m (160 ft)
Boats & landing craft carried	1 dinghy
Complement	4 officers, 25 enlisted
Armament	four 45 cm (17.7 in)torpedo tubes (2 eachbow andstern) 6torpedoes 1 × 3.7 cm (1.5 in)Hotchkiss gun 1 ×5 cm (2 in) SK L/40 gun (from 1915) 1 ×machine gun 12 P-Mines (March–December 1916)
Service record
Part of:	I Flotilla 1 August 1914 – 7 July 1915 Baltic Flotilla 7 July 1914 – 29 April 1916 Training Flotilla 20 April 1916 – 11 November 1918
Commanders:	Kptlt.Otto Weddigen[1] 1 October 1911 – 11 January 1915 Kptlt.Johannes Spieß[2] 12 January 1915 – 19 April 1916
Operations:	7 patrols
Victories:	13 merchant ships sunk (8,635 GRT) 4 warships sunk (43,350 tons) 1 auxiliary warship sunk (1,080 GRT)
Awards:	Iron Cross

SMU-9 was aGerman Type U 9U-boat. She was one of 329submarines serving in theImperial German Navy, and engaged incommerce raiding (Handelskrieg) duringWorld War I.

Her construction was ordered on 15 July 1908 and herkeel waslaid down byKaiserliche Werft inDanzig. She waslaunched on 22 February 1910 andcommissioned on 18 April 1910.

U-9 had anoverall length of 57.38 m (188 ft 3 in), herpressure hull was 48 m (157 ft 6 in) long. The boat'sbeam was 6 m (19 ft 8 in) (o/a), while the pressure hull measured 3.65 m (12 ft 0 in). She had adraught of 3.13 m (10 ft 3 in) with a total height of 7.05 m (23 ft 2 in). The boatdisplaced 493 t (485 long tons) when surfaced and 611 t (601 long tons) when submerged.^[3]

U-9 was fitted with twoKörting 8-cylinder plus two Körting 6-cylinder two-strokepetrol engines with a total of 1,000metric horsepower (735 kW; 986 bhp) for use on the surface and twoSiemens-Schuckertdouble-acting electric motors plus twoelectric motors with a total of 1,160 PS (853 kW; 1,144 shp) for underwater use. These engines powered two shafts, each with a 1.45 m (4.8 ft)propeller, which gave the boat a top surface speed of 14.2knots (26.3 km/h; 16.3 mph), and 8.1 knots (15.0 km/h; 9.3 mph) when submerged. Cruising range was 1,800nautical miles (3,300 km; 2,100 mi) at 14 knots (26 km/h; 16 mph) on the surface, and 80 nmi (150 km; 92 mi) at 5 knots (9.3 km/h; 5.8 mph) under water. Diving depth was 50 m (164 ft 1 in).^[3]

The U-boat was armed with four 50 cm (20 in)torpedo tubes, two fitted in thebow and two in thestern, and carried 6torpedoes. Originally, the boat was equipped with amachine gun, which was augmented with a 3.7 cm (1.5 in)Hotchkiss gun when war broke out in 1914. In 1915, an additional 5 cm (2.0 in) gun was fitted. WhenU-9 underwent a major refit in 1916, two mine-laying rails were added, which were later removed again. The boat'scomplement was 4 officers and 31 enlisted.^[3]

On 16 July 1914, the crew ofU-9 reloaded hertorpedo tubes while submerged, the first time any submarine had succeeded in doing so. On 1 August 1914,KapitänleutnantOtto Weddigen took command. On 22 September, while patrolling theBroad Fourteens, a region of the southernNorth Sea,U-9 found a squadron of three BritishCressy-classarmoured cruisers (HMS Aboukir,HMS Hogue, andHMS Cressy, sardonically nicknamed the "Live Bait Squadron"), which had been assigned to prevent German surface vessels from entering the eastern end of theEnglish Channel. She fired four of her torpedoes, reloading while submerged, and sank all three in less than an hour. 1,459 British sailors died.^[4] It was one of the most notablesubmarine actions of all time. Members of theAdmiralty who had consideredsubmarines mere toys no longer expressed that opinion after this event.^[5]

On 15 October,U-9 sank theprotected cruiserHMS Hawke.On 12 January 1915,Johannes Spieß relieved Weddigen, and commandedU-9 until 19 April 1916. During this period, she sank 13 ships totalling 8,635 GRT: 10 small fishing vessels and three British steamers (Don,Queen Wilhelmina andSerbino).

After April 1916, she was withdrawn from front-line duties to be used for training.

U-9 and the raiderSMS Emden were the only ships whichKaiser Wilhelm II awarded theIron Cross.

Date	Ship Name	Nationality	Tonnage[Note 1]	Fate[6]
22 September 1914	HMS Aboukir	United Kingdom	12,000	Sunk
22 September 1914	HMS Cressy	United Kingdom	12,000	Sunk
22 September 1914	HMS Hogue	United Kingdom	12,000	Sunk
15 October 1914	HMS Hawke	United Kingdom	7,350	Sunk
3 May 1915	Bob White	United Kingdom	191	Sunk
3 May 1915	Coquet	United Kingdom	176	Sunk
3 May 1915	Hector	United Kingdom	179	Sunk
3 May 1915	Hero	United Kingdom	173	Sunk
3 May 1915	Iolanthe	United Kingdom	179	Sunk
3 May 1915	Northward Ho	United Kingdom	180	Sunk
3 May 1915	Progress	United Kingdom	273	Sunk
4 May 1915	Rugby	United Kingdom	205	Sunk
5 May 1915	Straton	United Kingdom	198	Sunk
6 May 1915	Merrie Islington	United Kingdom	147	Sunk
8 May 1915	Don	United Kingdom	939	Sunk
8 May 1915	Queen Wilhelmina	United Kingdom	3,590	Sunk
16 August 1915	Serbino	United Kingdom	2,205	Sunk
5 November 1915	Dagö (n.4)	Imperial Russian Navy	1,080	Sunk

• Beesly, Patrick (1982).Room 40: British Naval Intelligence 1914–1918. London: H Hamilton.ISBN 978-0-241-10864-2.
• Fitzsimons, Bernard, ed.The Illustrated Encyclopedia of 20th Century Weapons and Warfare, "U-Boats (1905–18), Volume 23, p. 2534. London: Phoebus Publishing, 1978.
• Gröner, Erich; Jung, Dieter; Maass, Martin (1991).German Warships 1815–1945, U-boats and Mine Warfare Vessels. Vol. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press.ISBN 0-85177-593-4.*Halpern, Paul G. (1995).A Naval History of World War I. New York: Routledge.ISBN 978-1-85728-498-0.
• Koerver, Hans Joachim (2008).Room 40: German Naval Warfare 1914–1918. Vol I., The Fleet in Action. Steinbach: LIS Reinisch.ISBN 978-3-902433-76-3.
• Koerver, Hans Joachim (2009).Room 40: German Naval Warfare 1914–1918. Vol II., The Fleet in Being. Steinbach: LIS Reinisch.ISBN 978-3-902433-77-0.
• Rössler, Eberhard (1985).Die deutschen U-Boote und ihre Werften: U-Bootbau bis Ende des 1. Weltkriegs, Konstruktionen für das Ausland und die Jahre 1935–1945 [The German Submarines and Their Shipyards: Submarine Construction Until the End of the First World War] (in German). Vol. I. Koblenz:Bernard & Graefe.ISBN 3-7637-5213-7.
• Roessler, Eberhard (1997).Die Unterseeboote der Kaiserlichen Marine. Bonn: Bernard & Graefe.ISBN 978-3-7637-5963-7.
• Schroeder, Joachim (2002).Die U-Boote des Kaisers. Bonn: Bernard & Graefe.ISBN 978-3-7637-6235-4.
• Spindler, Arno (1966) [1932].Der Handelskrieg mit U-Booten. 5 Vols. Berlin: Mittler & Sohn. Vols. 4+5, dealing with 1917+18, are very hard to find:Guildhall Library, London, has them all, also Vol. 1–3 in an English translation: The submarine war against commerce.

• Photos of cruises of German submarine U-54 in 1916–1918.
• A 44 min. German film from 1917 about a cruise of the German submarine U-35.
• Room 40:Archived 15 October 2018 at theWayback Machine original documents, photos and maps about World War I German submarine warfare and BritishRoom 40 Intelligence fromThe National Archives, Kew, Richmond, UK.
• Helgason, Guðmundur."WWI U-boats: U 9".German and Austrian U-boats of World War I - Kaiserliche Marine - Uboat.net. Retrieved27 May 2007.

• Type U 9 submarines
• U-boats commissioned in 1910
• World War I submarines of Germany
• 1910 ships
• Ships built in Danzig
• Recipients of the Iron Cross (1914)

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