U-5-class submarine (Austria-Hungary)

U-5, the lead boat of the U-5 class, as seen in a pre-war postcard
Class overview
Builders	Whitehead & Co., Fiume[1]
Operators	Austro-Hungarian Navy
Preceded by	U-3 class
Succeeded by	U-7 class
Built	1909–1911
In commission	1910–1918
Completed	3
Lost	2
Preserved	0
General characteristics
Type	submarine
Displacement	240 t (240 long tons) surfaced 273 t (269 long tons) submerged[1]
Length	105 ft 4 in (32.11 m)[1]
Beam	13 ft 9 in (4.19 m)[1]
Draft	12 ft 10 in (3.91 m)[1]
Propulsion	2 × shafts 2 × 6-cylinder gasoline engines, 500 bhp (370 kW) total[2] 2 × electric motors, 230 shp (170 kW) total[1]
Speed	10.75 knots (19.91 km/h) surfaced 8.5 knots (15.7 km/h) submerged[1]
Range	800 nmi (1,500 km) @ 8.5 knots (15.7 km/h) surfaced 48 nmi (89 km) @ 6 knots (11.1 km/h) submerged[1]
Complement	19[1]
Armament	2 × 45 cm (17.7 in) torpedo tubes (both in front); 4 torpedoes[3]

The U-5 class was a class of three submarines or U-boats that were operated by the Austro-Hungarian Navy (German: Kaiserliche und Königliche Kriegsmarine or K.u.K. Kriegsmarine) before and during World War I. The class was a part of the Austro-Hungarian Navy's efforts to competitively evaluate three foreign submarine designs.

The design of the boats was based upon the Electric Boat Company's EB-17 (C-class), the first to be designed by the company's new chief designer, Lawrence York Spear.^[4] It featured a single, teardrop hull, which resembled the design of modern nuclear submarines.^[5] The class members were just over 105 feet (32 m) long and displaced 240 tonnes (240 long tons) surfaced and 273 tonnes (269 long tons) submerged. All were originally equipped with two bow torpedo tubes and could carry four torpedoes. The first two boats, U-5 and U-6, built specifically for the Austro-Hungarian Navy, to the same design as the United States C-class submarine were partially constructed in the United States and completed at Whitehead & Co. at Fiume. The third was completely constructed by Whitehead's at Fiume and purchased by Austria-Hungary to bolster their U-boat fleet after the outbreak of World War I.

All three boats had successes during World War I; between them they sank five ships with a combined tonnage of 22,391. In addition they captured seven ships as prizes and damaged Jean Bart, a French dreadnought of 22,189 tons displacement. All three boats were sunk during the war, though U-5, the lead boat of the class, was raised and recommissioned after her sinking. After the war's end, U-5, the only survivor of the class, was ceded to Italy as a war reparation and was broken up in 1920.