Type U 9 submarine

Class overview
Builders	Kaiserliche Werft Danzig
Operators	Imperial German Navy
Preceded by	Type U 5
Succeeded by	Type U 13
Completed	4
Lost	3
General characteristics
Displacement	493 tonnes (485 long 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 stroke paraffin motors with a total of 1,000 PS (740 kW; 990 shp) 2 × SSW electric 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)
Complement	4 officers, 25 enlisted
Armament	four 45 cm (17.7 in) torpedo tubes (2 each bow and stern) 6 torpedoes 1 × 3.7 cm (1.5 in) Hotchkiss gun 1 × 5 cm (2 in) SK L/40 gun (from 1915) 1 × machine gun

Type U 9 was a class of U-boats built during World War I by the Kaiserliche Marine.

Type U 9s had an overall length of 57.38 m (188 ft 3 in) The boats' beam was 6.00 m (19 ft 8 in), the draught was 3.65 m (12 ft 0 in). The boats displaced 493 tonnes (485 long tons) when surfaced and 611 t (601 long tons) when submerged.^[1]

Type U 9s were fitted with two Körting 6-cylinder and two 8-cylinder two-stroke paraffin engines with a total of 1,000 metric horsepower (735 kW; 986 bhp) for use on the surface and two SSW double-acting electric motors with a total of 860 kW (1,169 PS; 1,153 shp) for underwater use. These engines powered two shafts, which gave the boats a top surface speed of 14.2 knots (26.3 km/h; 16.3 mph), and 8.1 knots (15.0 km/h; 9.3 mph) when submerged. Cruising range was 3,250 nautical miles (6,020 km; 3,740 mi) at 9 knots (17 km/h; 10 mph) on the surface and 80 nautical miles (150 km; 92 mi) at 5 knots (9.3 km/h; 5.8 mph) submerged.^[1] Constructional diving depth was 50 m (164 ft 1 in).^[2]

The U-boats were armed with four 45 cm (18 in) torpedo tubes, two fitted in the bow and two in the stern, and carried six torpedoes. The boats' complement was 4 officers and 25 enlisted.^[1]

• 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.
• Möller, Eberhard; Brack, Werner (2004). The Encyclopedia of U-Boats. London: Chatham. ISBN 1-85367-623-3.
• Rössler, Eberhard (1981). The U-boat: The evolution and technical history of German submarines. London: Cassell & Co. ISBN 0-304-36120-8.