The were a

class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used differentl ...

of eight ''

kaibōkan or coastal defense ship was a type of naval ship used by the Imperial Japanese Navy during World War II for escort duty and coastal defense. The term escort ship was used by the United States Navy to describe this category of Japanese ships. ...

'' escort vessels built for the

Imperial Japanese Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrend ...

during

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 ...

. Five of the eight ships were sunk during the war. The class was also referred to by internal Japanese documents as the .

Background

The ''Mikura''-class ''

'', as with the torpedo boat, was a consequence of the 1930 London Naval Treaty, which placed limitations on the total destroyer tonnage the Imperial Japanese Navy was permitted. One way in which the treaty could be circumvented was to use a loophole in the treaty which permitted ships of between 600 and 2,000 tons, with no more than four guns over 76mm, no torpedoes, and with a maximum speed of no more than 20 knots. A new class of vessel was designed to use this loophole, and was given the obsolete designation of ''kaibōkan'' (''Kai'' = sea, ocean, ''Bo'' = defence, ''Kan'' = ship), which had previously been used to designate obsolete battleships which had been reassigned to coastal defense duties. The first of these vessels were the and ; however, after the start of the Pacific War, it became apparent that a design more capable of

anti-submarine warfare Anti-submarine warfare (ASW, or in older form A/S) is a branch of underwater warfare that uses surface warships, aircraft, submarines, or other platforms, to find, track, and deter, damage, or destroy enemy submarines. Such operations are t ...

was needed. The 1941 Rapid Naval Armaments Supplement Programme authorized eight of these new vessels, which were designated the ''Mikura''-class. Production began in late 1942 concurrently with later ''Etorofu''-class vessels.

Description

Although the ''Mikura''-class was based on the two previous classes of escort vessels and used a simplified version of the Etorofu-class hull, it presented a much different appearance, with a stepped bridge, smaller single smokestack located further aft, shape of the aft deckhouse, and the type of main gun. The ships measured

overall Overalls, also called bib-and-brace overalls or dungarees, are a type of garment usually used as protective clothing when working. The garments are commonly referred to as a "pair of overalls" by analogy with "pair of trousers". Overalls were ...

, with a beam of and a

draft Draft, The Draft, or Draught may refer to: Watercraft dimensions * Draft (hull), the distance from waterline to keel of a vessel * Draft (sail), degree of curvature in a sail * Air draft, distance from waterline to the highest point on a vesse ...

of .Chesneau, p. 205 They displaced at

standard Standard may refer to: Symbols * Colours, standards and guidons, kinds of military signs * Standard (emblem), a type of a large symbol or emblem used for identification Norms, conventions or requirements * Standard (metrology), an object th ...

load and at deep load. The ships had 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, each driving one

propeller shaft A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power and torque and rotation, usually used to connect ...

, which were rated at a total of for a speed of . The ships had a range of at a speed of .Jentschura, Jung & Mickel, p. 187 The

main battery A main battery is the primary weapon or group of weapons around which a warship is designed. As such, a main battery was historically a gun or group of guns, as in the broadsides of cannon on a ship of the line. Later, this came to be turreted ...

of the ''Mikura''-class consisted of three Type 10 120 mm AA guns — one in a enclosed turret forward and two in an open twin mount aft. These were dual-purpose guns capable of attacking both surface and aircraft targets. Anti-aircraft protection was by four Type 96 anti-aircraft guns in two twin-gun mounts abreast the bridge. The ''Mikura'' class was initially armed with 120 Type 95 depth charges with two Type 94 depth charge launchers and had a Model 93 sonar and a Type 93 hydrophone. Later in the war, a third Type 94 depth charge launcher was added on the stern and the paravanes were removed. During the Pacific War, the number of Type 96 anti-aircraft guns was increased with the addition of a triple-mount in front of the bridge and an additional four single-mounts. A Type 22 and a Type 13 radar were also added. A Type 97 trench mortar was also installed front of the bridge

Operational service

All eight vessels in the class saw extensive combat service in the

South China Sea The South China Sea is a marginal sea of the Western Pacific Ocean. It is bounded in the north by the shores of South China (hence the name), in the west by the Indochinese Peninsula, in the east by the islands of Taiwan and northwestern Phi ...

and the East China Sea, where they were used for convoy escort. Two American submarines may have been destroyed by ''Mikura''-class vessels, with ''Chiburi'' given credit for the sinking of on 8 November 1944 and ''Mikura'' given credit for assisting in the destruction of on March 28, 1945. Of the eight vessels in the class, five were lost in combat (four to USN submarines). One ship survived the war to be used for repatriation duties and one was given as a reparations to the

Republic of China Navy The Republic of China Navy (ROCN; ), also called the ROC Navy and colloquially the Taiwan Navy, is the maritime branch of the Republic of China Armed Forces (ROCAF). The service was formerly commonly just called the Chinese Navy during World W ...

, under whose flag it continued to serve until scrapped in 1963.

Ships in class

Notes

References