Plan 1828 ocean surveillance ship
 3-view image of Girin in 2009, before refit
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| Class overview | |
|---|---|
| Name: | Plan 1828 (Girin) class |
| Builders: | Samsan Shipyard, Haeju |
| Operators: | Menghe |
| Preceded by: | none |
| Succeeded by: | Plan 1850 ocean surveillance ship |
| Built: | 2001-2007 |
| In service: | 2003-present |
| Planned: | 3 |
| Completed: | 3 |
| General characteristics | |
| Type: | Ocean surveillance ship |
| Displacement: | 1500 tons |
| Length: | 65.2 m (overall) |
| Beam: | 25.3 m (overall) |
| Draft: | 7.6 m |
| Propulsion: |
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| Speed: | 10 knots |
| Range: | 3,000 nautical miles (5,500 km) at 8 knots |
| Complement: |
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Plan 1828 is the design designation for a type of ocean surveillance ship built in Menghe in the early 2000s. They are also sometimes called the Girin class after the first ship to be commissioned. They carry an experimental low frequency active sonar array and towed array sonar, and have greatly improved submarine detection capabilities compared to a conventional warship. Only three were built, with the class functioning mainly as a stepping stone to the larger Plan 1850 design which followed.
Design
The Plan 1828 design is the first Menghean military vessel to use a small-waterplane-area twin hull configuration. While structurally weaker than a conventional-hulled catamaran, the SWATH design offers greater stability in rough seas and a reduced acoustic signature. To further improve quieting, the class uses an integrated electric propulsion system, with four diesel generators in the above-water section powering electric motors in the submerged hulls.
The core feature of the Plan 1828 ships is the "Ilgi-gab" sonar suite. This consists of the Ŭ-808 low frequency active sonar and the Ŭ-515 passive towed array sonar. The Ŭ-808 consists of 20 sonar projectors spread out along a cable which is suspended between the twin hulls of the ship. It can scan in 360 degrees around the centerpoint, and the beam can be steered in angle to vary the depth. The entire array can also be lowered beyond its nominal depth, allowing the ship to search below the thermocline. It transmits in the 100-500 Hz frequency range. The Ŭ-515 listening array then receives echoes from this system and transmits them to the combat information center for processing. The Ŭ-515 array can also be used in a passive-only mode, to detect noise emitted by submarines.
Like ocean surveillance ships in other navies, the Plan 1828 (or Girin class) carries no meaningful armament. During the Innominadan Crisis, TŬG Bulsajo was spotted with 12.7mm machine guns on pintle mounts on the superstructure, but this appeared to be an improvised solution rather than a planned refit. Later, in 2016-2018, all ships in the class were refitted with Manhwagyŏng torpedo countermeasure launchers on either side of the superstructure. They remain highly vulnerable to attack.
Ships in the class
No standard nomenclature for experimental undersea surveillance ships (TŬG in Menghean nomenclature) existed when the Plan 1828s were ordered. On an ad-hoc basis, the Navy named the three vessels for mythological animals. The twelve ships of the Plan 1850 design would be named for animals of the Menghean zodiac.
| Name | Meaning | Builder | Laid down | Launched | Commissioned | Status |
|---|---|---|---|---|---|---|
| Girin | Qilin | Haeju (Samsan) | 2001 Sep 12 | 2002 Aug 24 | 2003 Nov 17 | In service |
| Bulsajo | Phoenix | Haeju (Samsan) | 2003 May 20 | 2004 Apr 08 | 2005 Feb 26 | In service |
| Ryongma | Longma | Haeju (Samsan) | 2005 Oct 03 | 2006 Sep 11 | 2007 Jul 30 | In service |