Japanese destroyer Hasu

The Momi class was designed with higher speed and better seakeeping than the preceding Enoki-class second-class destroyers.[1] The ships had an overall length of 280 feet (85.3 m) and were 275 feet (83.8 m) between perpendiculars. They had a beam of 26 feet (7.9 m), and a mean draft of 8 feet (2.4 m). The Momi-class ships displaced 850 long tons (864 t) at standard load and 1,020 long tons (1,036 t) at deep load.[2] Hasu was powered by two Parsons geared steam turbines, each driving one propeller shaft using steam provided by three Kampon water-tube boilers.[3] The turbines were designed to produce 21,500 shaft horsepower (16,000 kW) to give the ships a speed of 36 knots (67 km/h; 41 mph). The ships carried a maximum of 275 long tons (279 t) of fuel oil which gave them a range of 3,000 nautical miles (5,600 km; 3,500 mi) at 15 knots (28 km/h; 17 mph). Their crew consisted of 110 officers and crewmen.[4]

The main armament of the Momi-class ships consisted of three 12-centimeter (4.7 in) Type 3 guns in single mounts; one gun forward of the well deck, one between the two funnels, and the last gun atop the aft superstructure. The guns were numbered '1' to '3' from front to rear. The ships carried two above-water twin sets of 533-millimeter (21 in) torpedo tubes; one mount was in the well deck between the forward superstructure and the bow gun and the other between the aft funnel and aft superstructure.[2]

In 1939–40, Hishi was converted into a patrol boat. Her torpedo tubes, minesweeping gear, and aft 12 cm gun were removed in exchange for two triple mounts for license-built 25 mm (1 in) Type 96 light AA guns and 60 depth charges. In addition one boiler was removed, which reduced her speed to 18 knots (33 km/h; 21 mph) from 12,000 shp (8,900 kW). These changes made her top heavy and ballast had to be added which increased her displacement to 950 metric tons (935 long tons).[5][6]

Hasu, built at the Uraga Dock Company in Uraga, was launched on December 8, 1921, and completed on July 31, 1922. The ship served throughout the Sino-Japanese War and World War II. It was officially retired on October 12, 1945, and was scuttled as a breakwater in Fukui in 1946.

• Friedman, Norman (1985). "Japan". In Gardiner, Robert & Gray, Randal (eds.). Conway's All the World's Fighting Ships 1906–1921. Annapolis: Naval Institute Press. ISBN 0-87021-907-3.
• Hackett, Bob; Kingsepp, Sander & Cundall, Peter (2014). "IJN Second Class Destroyer Hasu: Tabular Record of Movement". KUCHIKUKAN! Stories and Battle Histories of the IJN's Second-Class Destroyers. Combinedfleet.com. Retrieved 16 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.
• Watts, Anthony J. & Gordon, Brian G. (1971). The Imperial Japanese Navy. Garden City, New York: Doubleday. ISBN 0-35603-045-8.