Tsugaru-class patrol vessel

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Tsugaru-class patrol vessel
JCG Settsu(PLH-07) right front view at Port of Kobe July 22, 2017 03.jpg
Settsu (PLH-07)
Class overview
Name: Tsugaru-class
Operators: Ensign of the Japanese Coast Guard.svg Japan Coast Guard
Preceded by: Sōya
Built: 1978–2001
In commission: 1979–present
Completed: 9
Active: 9
General characteristics of the Ryukyu-class
Type: PLH (Patrol vessel Large with Helicopter)
Displacement: 4,037 tonnes full load
Length: 105.4 m (346 ft)
Beam: 14.6 m (48 ft)
Draught: 8.0 m (26.2 ft)
Propulsion:
Speed: 23 knots
Range: 6,000 nmi
Complement: 69
Armament:
Aviation facilities: 1 × ASR helicopter

The Tsugaru-class patrol vessel (つがる型巡視船, Tsugaru-gata-junnshi-senn) is a class of PLH type patrol vessels of the Japan Coast Guard (JCG; former Maritime Safety Agency, MSA).[1][2]

Backgrounds[edit]

In late 1970s, it was clear that the new international rules on exclusive economic zone would need a considerable increase in the size of the Maritime Safety Agency fleets. In order to cover a wide ocean with a small number of vessels, JMSA began considering the shipping operation of air-sea rescue helicopters.[1]

At first, Sōya was built as a prototype in the plan of FY1977. Then, from the supplementary budget for the same year, construction of this class was started.[1]

Design[edit]

This class is roughly based on its prototype, Sōya, it is the same as having a long forecastle, but her icebreaking capability was omitted. In order to operate helicopter with these small ships, antiroll tanks and fixed fin stabilizers were set up. Since this class were built for a long time, the design are slightly different.[1] In particular, the overall improvement was added to the design of the last two vessels, so the United States Naval Institute dealt them as a separate group, Ryukyu-class.[2]

Like Sōya, these ships are not only a helicopter platform but also a command ship, so an operations room, OIC section, is installed adjacent to the bridge. The ability of Command and control is improved sequentially. Currently, Heli-TV system are installed to enable transmission of TV signals directly from a helicopter to OIC section. There are also SATCOM system to relay these TV signals to headquarters onshore.[3]

In the earliest ships, one L/60 Bofors 40 mm gun and one L/70 Oerlikon 20 mm cannon were set up. But both of them became obsolete, so later, 40 mm guns were replaced by L/90 Oerlikon 35mm guns, and 20 mm cannons were replaced by JM61-M 20 mm rotary cannons. And in the Ryukyu-class, the 20 mm rotary cannons are upgraded to JM61-RFS, remotely operated version with a optical director.[4]

In the early days, Bell 212 air-sea rescue helicopters were deployed as the shipboard helicopters. Then, with the aging of the Bell 212, they were superseded by the Sikorsky S-76C/D by 2016.[5]

In service[edit]

These ships are operated as command ships of each Regional Coast Guard Headquarters flotilla or task force, and conducting many search and rescue operations.[6]

In the Incident of Suspicious Boats off the Coast of Noto Peninsula, Chikuzen acted as a forward operating base of the Special Security Team (SST). She also fired warning shots by her JM61-M.[7]

With their high-endurance and aviation patrol capability, these ships also attend to overseas dispatch including counter-piracy operations in the Strait of Malacca.[6]

Ships in the class[edit]

Pennant Number Ship Name Builder Commission Decommission Homeport
PLH-02 Tsugaru IHI Corporation 17 April 1979 Hakodate
PLH-03 Ōsumi Tamano Shipyard,
Mitsui Engineering & Shipbuilding
18 October 1979 Kagoshima
PLH-04 Uruma
(former Uraga, Hayato)
Maizuru Shipyard,
Hitachi Zosen Corporation
5 March 1980 Naha
PLH-05 Zaō Nagasaki Shipyard,
Mitsubishi Heavy Industries
19 March 1983 Sendai
PLH-06 Okinawa
(former Chikuzen)
Kawasaki Shipbuilding Corporation 28 September 1983 Naha
PLH-07 Settsu Uraga Shipyard,
Sumitomo Heavy Industries
27 September 1984 Kobe
PLH-08 Echigo Tamano Shipyard,
Mitsui Engineering & Shipbuilding
28 February 1990 Niigata
PLH-09 Ryukyu Nagasaki Shipyard,
Mitsubishi Heavy Industries
31 March 2000 Naha
PLH-10 Daisen Tsurumi Shipyard,
JFE Engineering
1 October 2001 Maizuru

References[edit]

  1. ^ a b c d Asanaga, Youichirou; Ōtsuka, Yukitaka (1995). Japan Maritime Safety Agency - their vessels and aviation. Seizando-shoten publishing co.,ltd. pp. 120–126. ISBN 4-425-77041-2.
  2. ^ a b Wertheim, Eric (2013). The Naval Institute Guide to Combat Fleets of the World, 16th Edition. Naval Institute Press. pp. 383–384. ISBN 978-1591149545.
  3. ^ Okada, Hiroshi (December 2001). "Mechanism of JCG's helicopter patrol vessels". Ships of the World. Kaijin-sha (590): 146–151.
  4. ^ Nakanomyo, Masami (October 2015). "History of shipboard guns on JCG's patrol vessels". Ships of the World. Kaijin-sha (825): 168–173.
  5. ^ Nanba, Yoko (July 2016). "From 212 to 76C/D: Model change of JCG onboard helicopter". Ships of the World. Kaijin-sha (840): 146–151.
  6. ^ a b Henmi, Masakazu (December 2001). "PLH BUILDING PROGRAM AND ITS BACKGROUND". Ships of the World. Kaijin-sha (590): 141–145.
  7. ^ Hirose, Hajime (1999). "Research on new order formation with neighboring countries" (in Japanese). Retrieved 9 November 2017.

External links[edit]