Japanese submarine I-181

Japanese submarine I-181
Sister ship I-176 at sea, 1942
Career (Empire of Japan)
Name:	I-181
Builder:	Kure Naval Arsenal
Laid down:	1941?, as I-81
Launched:	2 May 1942
Completed:	24 May 1943
Renamed:	1942, as I-181
Struck:	30 April 1944
Fate:	Ran aground and wrecked, 16 January 1944
General characteristics
Class & type:	Kaidai-class submarine (KD7 Type)
Displacement:	1,862 t (1,833 long tons) surfaced 2,644 t (2,602 long tons) submerged
Length:	105.5 m (346 ft 2 in)
Beam:	8.25 m (27 ft 1 in)
Draft:	4.6 m (15 ft 1 in)
Installed power:	8,000 bhp (6,000 kW) (diesels) 1,800 hp (1,300 kW) (electric motors)
Propulsion:	Diesel-electric 2 × diesel engines 2 × electric motors
Speed:	23 knots (43 km/h; 26 mph) surfaced 8 knots (15 km/h; 9.2 mph) submerged
Range:	8,000 nmi (15,000 km; 9,200 mi) at 16 knots (30 km/h; 18 mph) surfaced 50 nmi (93 km; 58 mi) at 5 knots (9.3 km/h; 5.8 mph) submerged
Test depth:	80 m (260 ft)
Complement:	86
Armament:	6 × 533 mm (21 in) torpedo tubes (all bow) 1 × 120 mm (4.7 in) deck gun 1 × twin 25 mm (1.0 in) Type 96 AA gun

The Japanese submarine I-181 was a Kaidai-class attack submarine of the KD7 sub-class built for the Imperial Japanese Navy (IJN) during the 1940s. She was lost with all hands when she was ran aground in New Guinea after a battle with American ships in early 1944.

Design and description

The submarines of the KD7 sub-class were medium-range attack submarines developed from the preceding KD6 sub-class. They displaced 1,862 metric tons (1,833 long tons) surfaced and 2,644 metric tons (2,602 long tons) submerged. The submarines were 105.5 meters (346 ft 2 in) long, had a beam of 8.25 meters (27 ft 1 in) and a draft of 4.6 meters (15 ft 1 in). The boats had a diving depth of 80 m (260 ft) and a complement of 86 officers and crewmen.

For surface running, the boats were powered by two 4,000-brake-horsepower (2,983 kW) diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 900-horsepower (671 kW) electric motor. They could reach 23 knots (43 km/h; 26 mph) on the surface and 8 knots (15 km/h; 9.2 mph) underwater. On the surface, the KD7s had a range of 8,000 nautical miles (15,000 km; 9,200 mi) at 16 knots (30 km/h; 18 mph); submerged, they had a range of 50 nmi (93 km; 58 mi) at 5 knots (9.3 km/h; 5.8 mph).

The boats were armed with six internal 53.3 cm (21.0 in) torpedo tubes, all in the bow. They carried one reload for each tube; a total of a dozen torpedoes. They were originally intended to be armed with two twin-gun mounts for the 25 mm (1.0 in) Type 96 anti-aircraft gun, but a 120 mm (4.7 in) deck gun for combat on the surface was substituted for one 25 mm mount during construction.

Construction and career

Built by the Kure Naval Arsenal, the boat was laid down as I-81 and renamed I-181 in 1942. She was launched on 2 May 1942 and completed on 24 May 1943. I-181 ran aground in Kelanoa Harbour, New Guinea, and wrecked after a battle with an American destroyer and a PT boat with the loss of all 89 officers and crewmen. She was struck from the Navy List on 30 April 1944.

References

• Bagnasco, Erminio (1977). Submarines of World War Two. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-962-6. 
• Carpenter, Dorr B. & Polmar, Norman (1986). Submarines of the Imperial Japanese Navy 1904–1945. London: Conway Maritime Press. ISBN 0-85177-396-6. 
• Chesneau, Roger, ed (1980). Conway's All the World's Fighting Ships 1922–1946. Greenwich, UK: Conway Maritime Press. ISBN 0-85177-146-7. 
• Hackett, Bob; Kingsepp, Sander (2010). "IJN Submarine I-181: Tabular Record of Movement". combinedfleet.com. http://www.combinedfleet.com/I-181.htm. Retrieved 8 November 2015. 
• Jentschura, Hansgeorg; Jung, Dieter & Mickel, Peter (1977). Warships of the Imperial Japanese Navy, 1869–1945. Annapolis, Maryland: United States Naval Institute. ISBN 0-87021-893-X.