Dogsuli-class frigate

Dogsuli c.1971
Class overview
Builders:	Tayeong Shipyards, Daekan
Operators:	Daekanese People's Army Navy
Preceded by:	Seutokeo-class
Succeeded by:	Pyobeom-class
Built:	1967-1993
In service:	1971-present
Planned:	30
Completed:	20
Cancelled:	10
Active:	16
Lost:	1
Retired:	3
General characteristics
Class and type:	Guided Missile frigate
Displacement:	3,500 (initial variant)
Length:	116.28 metres (381.5 feet)
Beam:	13.4 m metres (43.96 feet)
Draught:	3.65 metres (12 feet)
Propulsion:	2 shaft; COGAG
Speed:	33 knots
Range:	8,700 km (4,697.6 nmi) at 14 knots (26 km/h)
Complement:	200
Sensors and processing systems:	LS-440 (MR-300 copy) air search radar LS-435 air search radar LS-333 fire control radar 4R90 fire control radar LS-276 gun fire control radar SJS-4 hull mounted sonar
Armament:	2x3-cell box launchers for KJ-1/2/3 AShMs x2 Type 76 twin 37mm guns x2 Type 61 twin 25mm guns x2 JP-70 naval gun x2 RBU-6000 ASW rocket launchers
Aircraft carried:	Later variants carry one HU-5 helicopter
Aviation facilities:	Later variants may feature one hangar

The Dogsuli-class frigate (Daekanese: 독수리, meaning "eagle") is a class of guided-missile frigates of the Daekanese People's Army Navy. The ships of the class were the first Daekanese vessels that were purpose-built to carry anti-ship cruise missiles, and they were also the first to feature a combined gas and gas (COGAG) propulsion system. The Dogsuli-class was intended to be used in hit-and-run tactics, hence the -for the time- advanced propulsion system that enabled it to reach speeds up to 33 knots. However, it was that exact propulsion system that was the cause of several teething problems at the start, as well as slow initial production rate. Despite its initial problems, upgraded variants of the Dogsuli remain in active DPAN service, with their retirement process beginning only in 2017.

History

The economic upturn caused by the success of the first three 5-year plans had serious influence on military affairs. The implementation of the new "Forward Defence" strategy was announced in the 12th Communist Party Congress in 1966, a year after the beginning of the Fourth 5-year plan. Among others, this new military strategy shifted the role of the navy from a token green water defence fleet - as per the previous "War of the masses" doctrine - to a more high-tech, modern force that could engage possible threats in more equal terms, and cause enough damage to delay any attack on the mainland, or even drive it away. The "Forward Defence" strategy called for the creation of a fleet of modern warships to replace the obsolete DPAN's inventory of mostly upgraded WW2-era vessels.

Despite the more ambitious posture of "Forward Defence", the DSPR leadership was under no illusions of being able to face the major powers of the world on an equal footing. The naval component of "Forward Defence" was still, as the name implies, a heavily defencive one that would ideally see the DPAN operating in a way that would expose it to enemy fire the least. The Dogsuli-class frigates are a design that is indicative of the new doctrine's tenents. It was the first Daekanese class of warships to feature combined gas and gas (COGAG) propulsion, meant to allow the vessel to get within missile range, fire, and then retreat as fast as possible.

The design was approved in late 1967 and the lead ship, the Dogsuli, was laid down later that year and was supposed to be launched in 1969, with the second ship following soon after. However, problems discovered in the GT-2 gas turbines that were supposed to be used, as well as their overall complexity, caused construction to be heavily delayed. After initial teething problems were fixed, construction continued and the Dogsuli was launched in early 1971, entering active service several months later. Further problems with the engines were discovered during the ship's sea trials, and all further production was paused. There were some suggestions to redesign the class to use steam turbines, but these were ignored.

With the upgraded GT-2D entering production in 1972, construction of further vessels was continued and the second vessel entered service in 1974. Reliability issues peristed until the introduction of the GT-5 in 1980, but these were deemed acceptable. Meanwhile, several other modifications were gradually made to the design, resulting in several variants.

The latest Dogsuli variants continue to serve in the DPAN today, but have began to be retired.

Variants

Dogsuli

The original batch of 4 ships, armed with two triple KJ-2 (later upgraded to KJ-3s) ASCM boxes, two JP-70 100m guns, two twin 37mm and two twin 25mm guns, as well as two RBU-6000 ASW rocket launchers. They mounted the LS-440 and LS-435 radars as well as the SJS-4 hull mounted sonar. They have all been retired.

Dogsuli II

The Dogsuli II is the second batch of 5 ships, first deployed in 1976. Its electronics suite was upgraded and was equipped for underway replenishment (UNREP). The most significant change is the replacement of the aft 100mm gun turret with a HHC-4 arm launcher.

Dogsuli III

The Dogsuli III is the third batch of 6 ships, first deployed in 1984. The aft of the ship was redesigned heavily and a helipad and hangar was installed for one HU-5 helicopter, while the HHC-4 arm launcher was moved forward, replacing the RBU-6000 launchers, while the smaller Type 65 ASW launchers were installed behind the main gun. Additionally, the triple EG-400 torpedo tubes were installed. The upgrade also replaced the LS-440 with a LS-534 3-D air and surface search radar and its overall electronics were upgraded.

Dogsuli IV

The Dogsuli IV is the fourth and last batch, it includes 4 ships and was first deployed in 1995. It is a direct development of the Dogsulu III, replacing the HHC-4 arm launcher with a 16-cell HHC-10, the JP-70 with the newer JP-72 naval gun, the KJ-3s with KJ-11s and the 37mm guns with 30mm JB-730 CIWS. The LS-435 was replaced with the SPS-49 and the LS-534 with the LS-570, while SaTnav antennas were installed and the ageing communication equipment was upgraded.