SM U-12 (Germany)

SM U-12 with seaplane on deck
History
German Empire
Name:	U-12
Ordered:	15 July 1908
Builder:	Kaiserliche Werft Danzig
Cost:	2,140,000 Goldmark
Yard number:	11
Launched:	6 May 1910
Commissioned:	13 August 1911
Fate:	Sunk 10 March 1915 off Eyemouth, Scotland
General characteristics
Class and type:	German Type U 9 submarine
Displacement:	493 t (485 long tons) surfaced 611 t (601 long tons) submerged
Length:	57.38 m (188 ft 3 in)
Beam:	6 m (19 ft 8 in)
Draught:	3.13 m (10 ft 3 in)
Installed power:	2 × Körting 6-cylinder and 2 × Körting 8-cylinder two stroke paraffin motors with 900 PS (660 kW; 890 shp) 2 × SSW electric motors with 1,040 PS (760 kW; 1,030 shp) 550 rpm surfaced 600 rpm submerged
Propulsion:	2 shafts
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)
Test depth:	50 m (160 ft)
Boats & landing craft carried:	1 dingi
Complement:	4 officers, 25 men
Armament:	4 × 45 cm (17.7 in) torpedo tubes (2 each bow and stern) with 6 torpedoes 1 × 3.7 cm (1.5 in) Hotchkiss gun
Service record
Part of:	I Flotilla 1 August 1914 – 10 March 1915
Commanders:	Kptlt. Walter Forstmann 1 August 1914 – 9 February 1915 Kptlt. Hans Kratzsch 10 February 1915 – 10 March 1915
Operations:	4 patrols
Victories:	1 merchant ship sunk (1,005 GRT) 1 warship sunk (810 tons)

SM U-12 was a German submarine, built in 1911 and sunk off Scotland in 1915. It was the first submarine to launch a plane at sea. U-12 was a Type U 9 U-boat built for the Imperial German Navy. Her construction was ordered on 15 July 1908 and her keel was laid down by Kaiserliche Werft in Danzig. She was launched on 6 May 1910 and commissioned on 13 August 1911.

The German Empire was the first nation to experiment with submarine aircraft carriers. Oberleutnant zur See Friedrich von Arnauld de la Perière of the Naval Air Service and U-12's Kapitanleutnant Walther Forstmann theorised that they could increase the range of their seaplanes by carrying the aircraft out to sea on the deck of submarine and launching the seaplanes after the sub partially submerged, allowing the plane to float off.

On 15 January 1915 U-12 left Zeebrugge transporting a Friedrichshafen FF.29 seaplane on its deck. Once beyond the safety of the breakwater, the captain realised that the heavy swell might swamp the aircraft and ordered the immediate launch of the seaplane. Forstmann flooded the sub's forward tanks and Arnauld floated the seaplane off the deck and took off from the sea. The German plane flew along the English coastline undetected and returned safely to Zeebrugge.

U-12 torpedoed the British gunboat HMS Niger at Deal on 11 November 1914. This was the first Allied casualty from submarines based in Belgian ports.

On 10 March 1915, while on patrol off the east coast of Britain, U-12 was hunted down by the three Royal Navy destroyers HMS Ariel, HMS Acheron and HMS Attack.