Japanese destroyer Keyaki (1944)

Designed for ease of production, the Matsu class was smaller, slower and more lightly armed than previous destroyers as the IJN intended them for second-line duties like escorting convoys, releasing the larger ships for missions with the fleet.[1] The ships measured 100 meters (328 ft 1 in) long overall, with a beam of 9.35 meters (30 ft 8 in) and a draft of 3.3 meters (10 ft 10 in).[2] Their crew numbered 210 officers and enlisted men.[3] They displaced 1,282 metric tons (1,262 long tons) at standard load and 1,554 metric tons (1,529 long tons) at deep load.[4] The ships had two Kampon geared steam turbines, each driving one propeller shaft, using steam provided by two Kampon water-tube boilers. The turbines were rated at a total of 19,000 shaft horsepower (14,000 kW) for a speed of 27.8 knots (51.5 km/h; 32.0 mph). The Matsus had a range of 4,680 nautical miles (8,670 km; 5,390 mi) at 16 knots (30 km/h; 18 mph).[5]

The main armament of the Matsu-class ships consisted of three 127-millimeter (5 in) Type 89 dual-purpose guns in one twin-gun mount aft and one single mount forward of the superstructure. The single mount was partially protected against spray by a gun shield. The accuracy of the Type 89 guns was severely reduced against aircraft because no high-angle gunnery director was fitted. The ships carried a total of twenty-five 25-millimeter (1 in) Type 96 anti-aircraft guns in 4 triple and 13 single mounts. The Matsus were equipped with Type 13 early-warning and Type 22 surface-search radars.[6] The ships were also armed with a single rotating quadruple mount amidships for 610-millimeter (24 in) torpedoes. They could deliver their 36 depth charges via two stern rails and two throwers.[2][6]

Sister ship Momi, 4 September 1944

Authorized in the late 1942 Modified 5th Naval Armaments Supplement Program,[7] Keyaki (Japanese elm) was laid down on 22 June 1944 at the Yokosuka Naval Arsenal and launched on 30 September.[8] Upon her completion on 15 December, the ship was assigned to Destroyer Squadron 11 of the Combined Fleet for training. On 15 March the ship was reassigned to the squadron's Destroyer Division 53. The squadron was briefly attached to the Second Fleet from 1–20 April before rejoining the Combined Fleet.[9]

The division was disbanded on 15 July and Keyaki was assigned to the Osaka Guard District. The ship was turned over to Allied forces at Yokosuka at the time of the surrender of Japan on 2 September and was stricken from the navy list on 5 October.[9] The destroyer was disarmed and used to repatriate Japanese personnel from late 1945 to 1947. Keyaki was turned over to the United States on 5 July of the latter year and was subsequently sunk as a target.[10]

• Chesneau, Roger, ed. (1980). Conway's All the World's Fighting Ships 1922–1946. Greenwich, UK: Conway Maritime Press. ISBN 0-85177-146-7.
• 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.
• Nevitt, Allyn D. (1998). "IJN Keyaki: Tabular Record of Movement". www.combinedfleet.com. Retrieved 21 September 2020.
• Stille, Mark (2013). Imperial Japanese Navy Destroyers 1919–45 (2): Asahio to Tachibana Classes. Botley, UK: Osprey Publishing. ISBN 978-1-84908-987-6.
• Whitley, M. J. (1988). Destroyers of World War Two: An International Encyclopedia. Annapolis, Maryland: Naval Institute Press. ISBN 0-87021-326-1.