The was a

destroyer escort Destroyer escort (DE) was the United States Navy mid-20th-century classification for a warship designed with the endurance necessary to escort mid-ocean convoys of merchant marine ships. Development of the destroyer escort was promoted by th ...

(or frigate) class built for the

Coastal Safety Force , also simply known as the Coastal Security Force, was an organization under the jurisdiction of the National Safety Agency, and existed from 1 August 1952 to 30 June 1954 in Japan. It was a maritime security agency established for the purpose o ...

(later

Japan Maritime Self-Defense Force , abbreviated , also simply known as the Japanese Navy, is the maritime warfare branch of the Japan Self-Defense Forces, tasked with the naval defense of Japan. The JMSDF was formed following the dissolution of the Imperial Japanese Navy (IJN) ...

, JMSDF) in the late 1950s. In the FY1953, the Japanese government ordered three destroyer escorts, and this class. These vessels were the first indigenous post-

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...

Japanese destroyer escorts, but their propulsion systems were different because the JMSDF tried to find the best way in the propulsion systems of future surface combatants. ''Akebono'' was a

steam-powered vessel Steam-powered vessels include steamboats and steamships. Smaller steamboats were developed first. They were replaced by larger steamships which were often ocean-going. Steamships required a change in propulsion technology from sail to paddlewheel ...

, but this class was diesel-powered vessels. So equipment of this class were almost the same as those of ''Akebono'', with two American 3"/50 caliber Mark 21 guns (or Type 54, the Japanese version) with two Mark 22 single mounts controlled by Mark 51 director each, two

Bofors 40 mm Bofors 40 mm gun is a name or designation given to two models of 40 mm calibre anti-aircraft guns designed and developed by the Swedish company Bofors: *Bofors 40 mm L/60 gun - developed in the 1930s, widely used in World War II and into the 1990s ...

anti-aircraft guns in a dual mount, a

Hedgehog A hedgehog is a spiny mammal of the subfamily Erinaceinae, in the eulipotyphlan family Erinaceidae. There are seventeen species of hedgehog in five genera found throughout parts of Europe, Asia, and Africa, and in New Zealand by introductio ...

anti-submarine mortar Anti-submarine mortars are artillery pieces deployed on ships for the purpose of sinking submarines by a direct hit with a small explosive charge. They are often larger versions of the mortar used by infantry and fire a projectile in relatively t ...

and eight

K-gun A depth charge is an anti-submarine warfare (ASW) weapon. It is intended to destroy a submarine by being dropped into the water nearby and detonating, subjecting the target to a powerful and destructive hydraulic shock. Most depth charges use h ...

depth charge throwers. And in 1959, all Mark 21 guns were replaced by Mark 22 rapid-fire guns with Mark 34 single mounts and Mark 63 GFCS was introduced in exchange of the reduction of Bofors 40 mm guns. This class had a twin-shaft machinery installation with two

diesel engine The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-ca ...

s (6,000ps each). This propulsion system was less powerful than the steam turbine machinery of ''Akebono'', but it was able to propel the ship at a top speed of still. The JMSDF appreciated the lower cost of maintenance of machinery of this class, so every Japanese destroyer escorts adopted diesel propulsion system until the period of

gas turbine A gas turbine, also called a combustion turbine, is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the directio ...

powered vessels.

Ships

References

{{Combatant ship classes of the Japan Maritime Self-Defense Force Frigate classes Frigates of the Japan Maritime Self-Defense Force