Ōtori-class torpedo boat
|Preceded by:||Chidori class|
|Succeeded by:||Matsu class (small destroyers)|
|Beam:||8.18 m (26 ft 10 in)|
|Draft:||2.76 m (9 ft 1 in)|
|Depth:||4.85 m (15 ft 11 in)|
|Speed:||30.5 knots (56.5 km/h; 35.1 mph)|
|Range:||4,000 nmi (7,400 km; 4,600 mi) at 14 kn (26 km/h; 16 mph)|
To circumvent the terms of the 1930 London Naval Treaty, which limited its total destroyer tonnage the Imperial Japanese Navy designed the Chidori class torpedo boat, but planned to arm it with half the armament of a Fubuki class destroyer. The resultant design was top-heavy and unstable, resulting in the 1934 Tomozuru Incident, in which one of the Chidori-class vessels capsized. The subsequent investigation revealed the fundamental design flaw, and the four vessels in the class which had been completed were extensively rebuilt, and the remaining sixteen vessels projected were cancelled in favor of a new design which would address these design issues from the beginning. Sixteen Ōtori-class vessels were ordered in the 1934 2nd Naval Armaments Supplement Programme, of which eight were completed between 1936 and 1937. The remaining eight were cancelled in favor of building additional submarine chasers.
Benefiting from the redesign of the Chidori-class, the Ōtori-class had a slightly longer hull with an increased beam. The bridge structure was also lower than on the Chidori-class to help keep the center-of-gravity low. Two Kampon geared turbines powered by two Kampon water-tube boilers produced a total of 19,000 shaft horsepower (14,000 kW), which gave the ships more power than the Chidori-class, and thus a slightly higher maximum speed of 30.0 knots (34.5 mph; 55.6 km/h)
The armament of the Ōtori-class was almost the same as for the rebuilt Chidori-class with a main battery of three single 12 cm/45 3rd Year Type naval guns which to elevate to 55 degrees for a limited anti-aircraft capability. The torpedo mount was upgraded from a twin to a triple torpedo launcher, and a single Type 94 depth charge launcher was carried. However, anti-aircraft weaponry was only a single license-built Vickers 40 mm (2 pounder pom pom).
During the Pacific War, in 1944 survivors had the aft gun removed, and up to three twin-mount and five single-mount Type 96 25mm AA guns were installed as well as a Type 22 and a Type 13 radar. The number of depth charges was increased to 48.
The Ōtori-class were used extensively from the start of the Pacific War to escort invasion convoys to the Philippines, Dutch East Indies and the Solomon Islands. Hiyodori sank the USS Amberjack (SS-219) during the Solomon Islands campaign on 16 February 1943. Seven of the eight ships in the class were sunk by submarines or air attack in the Pacific or the South China Sea and only Kiji survived to the end of the war.
Ships in class
|Ship and meaning||Builder||Laid down||Launched||Completed||Fate|
|Maizuru Naval Arsenal||8 November 1934||25 April 1935||10 October 1936||Sunk 12 June 1944 by aircraft of Task Force 58 NW of Saipan.|
|Ishikawajima Shipyards||26 November 1934||25 October 1935||20 December 1936||Sunk 17 November 1944 by USS Gunnel in South China Sea.|
|Yokohama Dock Company||19 December 1934||28 October 1935||7 December 1936||Sunk 24 September 1944 by aircraft in Sibuyan Sea.|
|Ōsaka Iron Works||4 March 1935||18 October 1935||15 January 1937||Sunk 26 September 1943 by USS Bluefish in Flores Sea.|
|Mitsui Engineering & Shipbuilding, Tamano||24 October 1935||26 January 1937||31 July 1937||Surrendered to Soviet Union on 3 October 1947 at Nakhodka. Renamed Vnimatel'nyy. Decommissioned on 31 October 1957.|
|Yokohama Dock Company||11 May 1936||20 January 1937||20 September 1937||Sunk 16 July 1945 by USS Baya at Java Sea.|
|Harima Shipyards||20 May 1936||30 January 1937||31 July 1937||Sunk 8 November 1944 by USS Gunnel W of Luzon.|
|Ishikawajima Shipyards||28 May 1936||25 January 1937||7 August 1937||Sunk 16 October 1944 by aircraft at Hong Kong.|
|Cancelled in 1937.|
- Ōtori was 1,012 tons for battle condition.
- Kari was equipped 2 × Type 96 25 mm (0.98 in) AA guns.
- Stille, Mark (2017). Imperial Japanese Navy Antisubmarine Escorts 1941–45. Oxford, UK: Osprey Publishing. pp. 18–20. ISBN 978 1 4728 1817 1.
- The cancelled units, Torpedo boats #13 to #20 under the 1934 Programme, were projected to have been named Hatsutaka, Aotaka, Wakataka, Kumataka ("bear hawk"), Yamadori ("mountain bird"), Mizudori ("water fowl"), Umidori ("seabird") and Komadori; however, no contracts were placed by the time the order was changed in 1937 in favour of Submarine chasers #4 to #11.
- Collection of writings by Sizuo Fukui Vol.5, Stories of Japanese Destroyers, Kōjinsha (Japan) 1993, ISBN 4-7698-0611-6
- Model Art Extra No.340, Drawings of Imperial Japanese Naval Vessels Part-1, Model Art Co. Ltd. (Japan), October 1989, Book code 08734-10
- The Maru Special, Japanese Naval Vessels No.39 Japanese Torpedo Boats, Ushio Shobō (Japan), May 1980, Book code 68343-40