was the

lead ship The lead ship, name ship, or class leader is the first of a series or class of ships all constructed according to the same general design. The term is applicable to naval ships and large civilian vessels. Large ships are very complex and may ...

of her class of four

escort ship Ocean escort was a type of United States Navy warship. They were an evolution of the World War II destroyer escort types. The ocean escorts were intended as convoy escorts and were designed for mobilization production in wartime or low-cost mass ...

s 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 surrender ...

during World War II.

Background and description

The Japanese called these ships ''

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. ...

'', "ocean defence ships", (''Kai'' = sea, ocean, ''Bo'' = defence, ''Kan'' = ship), to denote a multi-purpose vessel. They were initially intended for patrol and fishery protection,

minesweeping Minesweeping is the practice of the removal of explosive naval mines, usually by a specially designed ship called a minesweeper using various measures to either capture or detonate the mines, but sometimes also with an aircraft made for that ...

and as convoy escorts. 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 Beam may refer to: Streams of particles or energy *Light beam, or beam of light, a directional projection of light energy **Laser beam *Particle beam, a stream of charged or neutral particles **Charged particle beam, a spatially localized grou ...

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 vessel ...

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-call ...

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. 186 The main armament of the ''Shimushu'' class consisted of three Type 3 guns in single mounts, one

superfiring Superfiring armament is a naval military building technique in which two (or more) turrets are located in a line, one behind the other, with the second turret located above ("super") the one in front so that the second turret can fire over the ...

pair aft and one mount forward of the

superstructure A superstructure is an upward extension of an existing structure above a baseline. This term is applied to various kinds of physical structures such as buildings, bridges, or ships. Aboard ships and large boats On water craft, the superstruct ...

. They were built with four Type 96 anti-aircraft guns in two twin-gun mounts, but the total was increased to 15 guns by August 1943. A dozen

depth charge 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 Shock factor, hydraulic shock. Most depth ...

s were stowed aboard initially, but this was doubled in May 1942 when their minesweeping gear was removed. The anti-submarine weaponry later rose to 60 depth charges with a Type 97 trench mortar and six depth charge throwers.

Construction and career

''Shimushu'' participated in the landings in Thailand, escorting the 55th IJA Infantry Division to landings at Nakhon on 8 December 1941. She also escorted various other invasion convoys to

Malaya Malaya refers to a number of historical and current political entities related to what is currently Peninsular Malaysia in Southeast Asia: Political entities * British Malaya (1826–1957), a loose collection of the British colony of the Straits ...

Sumatra Sumatra is one of the Sunda Islands of western Indonesia. It is the largest island that is fully within Indonesian territory, as well as the sixth-largest island in the world at 473,481 km2 (182,812 mi.2), not including adjacent i ...

, and

Palembang Palembang () is the capital city of the Indonesian province of South Sumatra. The city proper covers on both banks of the Musi River on the eastern lowland of southern Sumatra. It had a population of 1,668,848 at the 2020 Census. Palembang ...

. Using her sonar, she located the British

battlecruiser The battlecruiser (also written as battle cruiser or battle-cruiser) was a type of capital ship of the first half of the 20th century. These were similar in displacement, armament and cost to battleships, but differed in form and balance of attr ...

on 29 January 1942, being the first ship to locate the submerged wreck. ''Shimushu'' participated in the HI-40 convoy disaster of 19–24 February 1944, in which all six oilers that were escorted by her — and only her, as she was the lone escort vessel — Nampo Maru were torpedoed and sunk by the American submarines and . After that convoy disaster, the Naval General staff discontinued assigning only one escort to convoys and organized larger convoys with more escorts. ''Shimushu'' participated in the TA No. 2 and 3, the Japanese effort to hold

Leyte Leyte ( ) is an island in the Visayas group of islands in the Philippines. It is eighth-largest and sixth-most populous island in the Philippines, with a total population of 2,626,970 as of 2020 census. Since the accessibility of land has be ...

island, and claimed one of the five

B-25 Mitchell The North American B-25 Mitchell is an American medium bomber that was introduced in 1941 and named in honor of Major General William "Billy" Mitchell, a pioneer of U.S. military aviation. Used by many Allied air forces, the B-25 served in ...

medium bomber A medium bomber is a military bomber Fixed-wing aircraft, aircraft designed to operate with medium-sized Aerial bomb, bombloads over medium Range (aeronautics), range distances; the name serves to distinguish this type from larger heavy bombe ...

s lost in the first wave. On 25 November, ''Shimushu'' was torpedoed by the submarine and lost her bow, and was repaired by 20 January 1945. The ship spent more than a year on repatriation duty and was ceded to the Soviet Union on 5 July 1947. The ship served in the Soviet Pacific Ocean Fleet as patrol ship ''EK-31'' (1947), dispatch ship ''PS-25'' (1948), repair ship ''PM-74'' (1957). She was decommissioned on 16 May 1959 and scrapped.

Notes

References

* * *

External links

*http://www.combinedfleet.com/Shimushu_t.htm {{DEFAULTSORT:Shimushu World War II naval ships of Japan Shimushu-class escort ships 1939 ships Ships built by Mitsui Engineering and Shipbuilding Patrol vessels of the Soviet Navy