SM U-6 (Austria-Hungary)

U-6, as seen in a pre-war postcard
History
Austria-Hungary
Name:	SM U-6
Ordered:	1906
Builder:	Whitehead & Co., Fiume
Laid down:	21 February 1908
Launched:	12 June 1909
Commissioned:	1 July 1910
Fate:	trapped in anti-submarine net and scuttled, 13 May 1916
Service record
Commanders:	Georg Ritter von Trapp (July 1910 – June 1913) Nikolaus Halavanja (June 1913 – July 1915) Albrecht Graf von Attems (July – August 1915) Urban Passerar (August 1915) Lüdwig Eberhardt (August – October 1915) Nikolaus Halavanja (October – November 1915) Hugo von Falkhausen (November 1915 – May 1916)
Victories:	1 warship (756 GRT) sunk
General characteristics
Class and type:	U-5-class submarine
Displacement:	240 t surfaced 273 t submerged
Length:	105 ft 4 in (32.11 m)
Beam:	13 ft 9 in (4.19 m)
Draft:	12 ft 10 in (3.91 m)
Propulsion:	2 × shafts 2 × 6-cylinder gasoline engines, 500 bhp (370 kW) total 2 × electric motors, 230 shp (170 kW) total
Speed:	10.75 knots (19.91 km/h) surfaced 8.5 knots (15.7 km/h) submerged
Range:	800 nmi (1,500 km) at 8.5 knots (15.7 km/h) surfaced 48 nmi (89 km) at 6 knots (11.1 km/h) submerged
Complement:	19
Armament:	2 × 45 cm (17.7 in) torpedo tubes (both in front) 4 torpedoes

SM U-6 or U-VI was a U-5-class submarine or U-boat built for and operated by the Austro-Hungarian Navy (German: Kaiserliche und Königliche Kriegsmarine or K.u.K. Kriegsmarine) before and during the First World War. The submarine was built as part of a plan to evaluate foreign submarine designs, and was the second of three boats of the class built by Whitehead & Co. of Fiume after a design by Irishman John Philip Holland.

U-6 was laid down in February 1908 and launched in June 1909. The double-hulled submarine was just over 105 feet (32 m) long and displaced between 240 and 273 tonnes (265 and 301 short tons), depending on whether surfaced or submerged. U-6's design had inadequate ventilation and exhaust from her twin gasoline engines often intoxicated the crew. The boat was commissioned into the Austro-Hungarian Navy in July 1910, and served as a training boat—sometimes making as many as ten cruises a month—through the beginning of the First World War in 1914.

The submarine had only one wartime success, which was sinking a French destroyer in March 1916. Later that year, in May, U-6 became entangled in anti-submarine netting deployed as part of the Otranto Barrage. Coming under fire from Royal Navy's drifters running the nets, U-6 was abandoned and sunk. All of her crewmen were rescued and were held in captivity through the end of the war.