Japanese Type 6 submarine

Holland-type submarine No.6
Class overview
Builders	Kawasaki Dockyards, Kobe
Operators	Imperial Japanese Navy
Preceded by	Kaigun Type 1 class
Succeeded by	Ha-1 class
In commission	1906–1920
Completed	2
Retired	2
General characteristics
Type	Submarine
Displacement	Submarine No.6: 57 long tons (58 t) surfaced 64 long tons (65 t) submerged Submarine No.7: 78 long tons (79 t) surfaced 95 long tons (97 t) submerged
Length	22.5 m (73 ft 10 in) 25.5 m (83 ft 8 in) (Submarine No.7)
Beam	2.1 m (6 ft 11 in) (Submarine No.6) 2.4 m (7 ft 10 in) (Submarine No.7)
Draft	2 m (6 ft 7 in) (Submarine No.6) 2.3 m (7 ft 7 in) (Submarine No.7)
Installed power	300 hp (220 kW) (gasoline engines) 22 hp (16 kW) (electric motors)
Propulsion	Gasoline engines Electric motors 1 shaft
Speed	8.5 knots (15.7 km/h; 9.8 mph) surfaced 4 knots (7.4 km/h; 4.6 mph) submerged
Range	184 nmi (341 km; 212 mi) at 8 knots (surfaced) 12 nmi (22 km; 14 mi) at 4 knots (submerged)
Test depth	30.5 metres (100 ft)
Complement	16 officers and enlisted
Armament	2 × 18 in (460 mm) bow torpedo tubes (2 × torpedoes)

The No.6-class submarine (第六型潜水艦, Dairoku-gata sensuikan) was the first class of submarines of the Imperial Japanese Navy built domestically in Japan. Consisting of two vessels, these submarines were highly modified versions of Holland-class vessels designed in the United States.