The is a class of 1,000 ton-class PL type

patrol vessels A patrol boat (also referred to as a patrol craft, patrol ship, or patrol vessel) is a relatively small naval vessel generally designed for coastal defence, border security, or law enforcement. There are many designs for patrol boats, and they ...

of the Japan Coast Guard (JCG).

Background

In the 2000s, the JCG was building 1,000-ton class PLs with a high speed planing hull, such as and es. Although these ships were excellent in security missions, they were also unsuitable for rescue missions because of their poor low-speed stability and cruising capacity. Since the mass retirement of the was planned in the 2010s, general-purpose ships as replacements were needed. For this purpose, construction of this class was started under the FY2009 supplement budget. As a result of emphasis on versatility, the price soared, only two ships were built, more reasonable was built from the following fiscal year. However, after that, additional construction was done to deploy on the

Senkaku Islands The are a group of uninhabited islands in the East China Sea, administered by Japan. They are located northeast of Taiwan, east of China, west of Okinawa Island, and north of the southwestern end of the Ryukyu Islands. They are known in main ...

in the FY2012 budgets. And construction is continuing from FY 2013 onwards, as construction costs have been reduced due to the mass production effect of this large-scale construction.

Design

Due to the demand for multi-mission capabilities, displacement hull made of steel was adopted. Also, since low-speed stability was required,

antiroll tanks Antiroll tanks are tanks fitted onto ships in order to improve the tank's response to roll motion. Fitted with baffles intended to slow the rate of water transfer from the port side of the tank to the starboard side and the reverse, the tanks are d ...

was also installed in addition to fin stabilizers. The superstructure is made of

aluminium alloy An aluminium alloy (or aluminum alloy; see spelling differences) is an alloy in which aluminium (Al) is the predominant metal. The typical alloying elements are copper, magnesium, manganese, silicon, tin, nickel and zinc. There are two principal ...

, but the bridge has

bulletproofing Bulletproofing is the process of making an object capable of stopping a bullet or similar high velocity projectiles (e.g. shrapnel). The term bullet resistance is often preferred because few, if any, practical materials provide complete protectio ...

structure introduced. A

helipad A helipad is a landing area or platform for helicopters and powered lift aircraft. While helicopters and powered lift aircraft are able to operate on a variety of relatively flat surfaces, a fabricated helipad provides a clearly marked hard s ...

is set on the stern deck. Although there is no

hangar A hangar is a building or structure designed to hold aircraft or spacecraft. Hangars are built of metal, wood, or concrete. The word ''hangar'' comes from Middle French ''hanghart'' ("enclosure near a house"), of Germanic origin, from Frankish ...

, they can supply fuel and electric power to a helicopter on board. As a main weapon, a JM61-RFS 20 mm

rotary gun A rotary cannon, rotary autocannon, rotary gun or Gatling cannon, is any large-caliber multiple-barreled automatic firearm that uses a Gatling-type rotating barrel assembly to deliver a sustained saturational direct fire at much greater rate ...

system with an optical director was installed on the early ships built under the FY2009 and FY2012. And more powerful

Bushmaster II The Mk44 Bushmaster II is a 30 mm chain gun manufactured by Northrop Grumman. It is a derivative of the 25 mm M242 Bushmaster, and uses 70% of the same parts as the M242 while increasing the firepower by as much as 50% with the 20% increase ...

30 mm 30 mm caliber is a specific size of popular autocannon ammunition. Such ammunition includes NATO standard 30×113mmB and 30×173mm (STANAG 4624), Soviet 30×155mmB, 30×165mm, and 30×210mmB, Yugoslav 30×192mm, Anglo-Swiss 30×170mm, and ...

chain gun system was installed on the late ships built under the FY2013 and following fiscal years.

In service

The 10 ''Kunigami'' class ships leading JCG's increased focus on grey-zone challenges along with 2 Hateruma-class patrol vessels has made the base at Ishigaki JCG's largest base, surpassing Yokohama. The ships of FY2012 constitutes the main force of the task force deployed around the Senkaku Islands. And the ships built under the FY2013 and following fiscal years were deployed as replacements of the ''Shiretoko'' class.

Ships in the class

References

{{Reflist Patrol vessels of the Japan Coast Guard Patrol ship classes

Background

Design

In service

Ships in the class

See also

References