Japanese submarine I-9

The submarines of the A1 type were versions of the preceding J3 class with superior range, improved aircraft installation, and were fitted as squadron flagships.[1] They displaced 2,966 tonnes (2,919 long tons) surfaced and 4,195 tonnes (4,129 long tons) submerged. The submarines were 113.7 meters (373 ft 0 in) long, had a beam of 9.5 meters (31 ft 2 in) and a draft of 5.3 meters (17 ft 5 in). They had a diving depth of 100 meters (330 ft).[1]

For surface running, the boats were powered by two 6,200-brake-horsepower (4,623 kW) diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 1,200-horsepower (895 kW) electric motor. They could reach 19 knots (35 km/h; 22 mph) on the surface[2] and 8.25 knots (15.28 km/h; 9.49 mph) underwater. On the surface, the A1s had a range of 16,000 nautical miles (30,000 km; 18,000 mi) at 16 knots (30 km/h; 18 mph); submerged, they had a range of 90 nmi (170 km; 100 mi) at 3 knots (5.6 km/h; 3.5 mph).[3]

The boats were armed with four internal bow 53.3 cm (21.0 in) torpedo tubes and carried a total of 18 torpedoes. They were also armed with a single 140 mm (5.5 in)/40 deck gun and two twin 25 mm (1 in) Type 96 anti-aircraft guns.[3]

Unlike the J3 class, the aircraft hangar is integrated into the conning tower and faces forward; the positions of the deck gun and the catapult were exchanged so the aircraft can use the forward motion of the ship to supplement the speed imparted by the catapult.[3]

On 11 December 1941, I-9 sank SS Lahaina 700 miles northeast of Oahu. On 19 June 1942, the boat damaged US Army Transport General W. C. Gorgas with gunfire. On 25 August, she was depth charged and damaged by the destroyers USS Grayson (DD-435), USS Monssen (DD-436), and USS Patterson (DD-392). She made supply runs to Guadalcanal from November 1942 to January, 1943. She was sunk off Kiska (58°08′N 177°38′E) on 13 June 1943 by the destroyer USS Frazier (DD-607).[4][5][6]

• Bagnasco, Erminio (1977). Submarines of World War Two. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-962-6.
• Boyd, Carl & Yoshida, Akikiko (2002). The Japanese Submarine Force and World War II. Annapolis, Maryland: Naval Institute Press. ISBN 1-55750-015-0.
• 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 (2012). "IJN Submarine I-9: Tabular Record of Movement". SENSUIKAN! Stories and Battle Histories of the IJN's Submarines. Combinedfleet.com. Retrieved 18 August 2015.
• Hashimoto, Mochitsura (1954). Sunk: The Story of the Japanese Submarine Fleet 1942 – 1945. Colegrave, E.H.M. (translator). London: Cassell and Company. ASIN B000QSM3L0.
• Stille, Mark (2007). Imperial Japanese Navy Submarines 1941-45. New Vanguard. 135. Botley, Oxford, UK: Osprey Publishing. ISBN 978-1-84603-090-1.