Chŏndong-class destroyer

File:DD Nunbora.png DD Nunbora as it appeared during the Battle of the Aqaba Sea.
Class overview
Name:	Chŏndong-class
Operators:	Menghe
Preceded by:	Angae-class destroyer
Succeeded by:	Emil-si class destroyer
Built:	1981-1999
In service:	1994-present
Planned:	13
Completed:	13
Active:	6
Lost:	2
Retired:	3
Preserved:	2
General characteristics Chŏndong-I subclass
Type:	Guided missile destroyer
Displacement:	3,500 tonnes fully loaded
Length:	126.1 m at waterline, full load 134.5 m overall
Beam:	12.8 m
Draught:	4.73 m to keel, full load 5.49 m including sonar bulge
Propulsion:	CODOG 2 × diesel engine, 4,000 shp each 2 × gas turbine, 24,000 shp each 2 shafts
Speed:	33 knots
Range:	2,000 nm (3,700 km) at 18 knots
Complement:	282
Sensors and processing systems:	HR-200 3D search radar HR-110 VHF search radar HR-280 surface search radar STH-775 hull-mounted sonar
Electronic warfare & decoys:	4 × P203 ECM 1 × ShMTK-761 ship-to-ship datalink
Armament:	1 × HP-130/2 twin dual purpose 130mm gun 2 × 4-tube launcher for YDH-25 AShM 2 × twin-arm launcher for YDG-32 SAM 4 × GBM-30/6 CIWS 2 × 2 533mm torpedo tube 2 × RBDJ-21/12 depth charge rocket projector
Aircraft carried:	1 × GHZ-28 helicopter
Aviation facilities:	landing pad only

The Chŏndong-class destroyers (Menghean: 천둥급 구축함, Chŏndong-gŭb Guchugham) were a series of guided missile destroyers built in Menghe from the mid-1980s to the late 1990s. They are Menghe's most numerous postwar destroyer class in terms of hulls built, though the Haeju-class destroyers are the most numerous among hulls still in service.

Like contemporary destroyer classes in the Federation of Socialist Republics, they were primarily designed around anti-surface warfare, and carried a powerful main battery of supersonic anti-ship missiles. Conversely, their anti-submarine armament was relatively poor, and their anti-air armament was limited to short-range self-defense. Compared to the FSR's destroyers, they were also smaller and more compact, with reduced endurance at sea, optimized for rapid sortie missions rather than prolonged operations at sea.

Owing to their small size and constrained role, they are sometimes described as frigates; a few foreign intelligence services have remarked that in terms of role, they more closely resembled large corvettes. At the time of their construction, Menghean sources formally classified them as "Attack Destroyers" (Gonggyŏk Guchugham), but they were reclassified to destroyer status in 2006.

Development

During the 1970s and 1980s, the Democratic People's Republic of Menghe faced pressing security threats from the Organized States of Columbia to the west and New Oyashima to the east. Its previous naval buildup had been ambitious, and included the construction of two light aircraft carriers, yet the Menghean People's Navy was still far behind its Columbian and Oyashimese counterparts in terms of fleet size and individual ship capability. To compensate for this shortcoming, in the late 1970s the Ministry of Defense ordered the development of a new warship optimized for anti-shipping missions.

Design process

The resulting design was primarily the work of Jin Gi-tae, the chief naval architect at the 55th Naval Institute. Rejecting earlier proposals that had called for a large and flexible destroyer, Jin insisted on a compact, efficient warship built around a clear mission. This choice was a function of Menghe's military needs at the time: facing two opponents with greater industrial capacity, Jin Gi-tae believed that the only way to balance in national defense was to create a warship that could be produced in large numbers and easily maintained. This meant restricting features and capabilities superfluous to the core mission's needs.

During the design phase, Menghean naval architects consulted extensively with military advisors from the Federation of Socialist Republics, both for overall ship design and the individual electronic systems involved. The ships' gas-turbine engines were imported from the FSR, as Menghe lacked the necessary facilities to manufacture high-performance turbines independently, and the anti-ship missiles were domestically produced copies of FSR weapons and incorporated a number of imported components. In terms of their overall configuration, the Chŏndong class loosely resembled contemporary Letnevian destroyer classes, though Jin Gi-tae's revisions heavily reduced the displacement.

Construction

The first hull was laid down in 1981, and commissioned in 1985. Built under conditions of considerable secrecy, its name was not known in the West, and OSN intelligence officials tentatively termed it the Wihae-class after the fishing town where it was first spotted on satellite images.

Construction work was complicated by Menghe's first nuclear test in November 1984, which officially placed Menghe in violation of the STAPNA agreement. Facing an embargo with its few remaining trading partners, including the FSR, Menghe was unable to secure key components for the hulls still under construction. Enough turbines had been imported for five hulls, but planned construction called for at least ten in total, and since then the security threat had worsened.

In July 1986, the Politburo inquired about the possibility of modifying the design to rely on steam turbine propulsion, which had been used on the Taepung and Angae classes. Jin Gi-tae strongly objected, as this would not only severely curtail performance but would also require a major re-design of the engine compartment. After a prolonged argument against visiting Party officials, Jin was relieved of his post and handed a prison sentence. His successor did, in fact, design a Chŏndong derivative with steam-turbine propulsion, but construction never started due to the growing political turmoil of 1987.

After the Decembrist Revolution, the international embargo on Menghe was lifted, and construction of the remaining ships resumed. Jin Gi-tae was freed from prison, but chose to retire from the military design industry, leaving the Chŏndong program to his subordinates. Choe Sŭng-min was reportedly very favorable toward the ships' efficient design, and once the two remaining hulls in drydock were finished, he ordered the construction of six more, this time built to a modified standard. Politics played a major role in the class's continuation, as Menghe's security threat from New Oyashima had declined, and the country now had easier access to more advanced naval equipment.

Design

Main armament

The core armament of the Chŏndong-class destroyers was a powerful forward-facing battery of eight YDH-25 supersonic anti-ship missiles, four on each side of the bridge. These were copied from a Letnevian design, and had a top speed of Mach 3, with a maximum range of 120 kilometers on an all-low trajectory. New missiles imported in 1992 extended this range to 240 kilometers through the use of a more efficient engine and a mid-low trajectory. During the sea-skimming final approach, the supersonic missiles would leave the target with under 30 seconds between detection and impact.

Readying the missiles for launch took over one minute, a longer time than on the FSR's warships, with an additional 15 seconds between ready status and launch. The launchers themselves could only fire missiles at 10-second intervals, but this could be reduced to 5 by alternating between port and starboard batteries; total time to fire a full salvo was in theory just 40 seconds, but could be longer with a less prepared crew. The missiles could only engage targets 60 degrees to either side of the bow, requiring the ship to face toward its target during the launch phase.

Other armament

The ships' forward-facing gun mount was a twin-barrel, 130mm HP-130/2 81-nyŏn, different from the HP-130/2 67-nyŏn on the Taepung-class destroyers. It had an improved autoloading system, and could fire at a maximum rate of 20 rounds per minute per barrel. In addition to surface targets, it could also engage aircraft and incoming missiles with the help of an improved fire-control system.

For self-defense against aircraft, the type carried two twin-arm launchers for the YDG-32 SAM. Each launcher carried 20 missiles in a carousel arrangement below the deck, and could automatically reload in a 20-second process. With a range of 15 kilometers, the missiles were limited to short-range defense, and even then they were constrained by the launcher's reloading time. Additional anti-aircraft / anti-missile armament came in the form of four [[GBM-30/6#GBM-30.2F6|GBM-30/6}} CIWS guns, two on either side. These offered good protection along the sides and rear, but had a 60-degree blind spot over the ship's forward arc, which was only covered by the 130mm turret and YDG-32 launcher.

For anti-submarine operations, the ships relied on two pairs of traversing 533mm torpedo tubes, which could be used to fire sonar-guided torpedoes or the RDJH-3 anti-submarine rocket. Two RBDJ-21/12 rocket-propelled depth charge projectors on the quarterdeck provided close-range anti-submarine defense, but were restricted to a small magazine by their location.

Sensors and electronics

The early Chŏndong-class destroyers carried two radar units: one HR-200 3D search radar on the forward mast, and one HR-110 VHF-band air-search radar using Yagi antennas. This provided some measure of redundancy in the event that one radar unit was damaged. Both radar systems considerably out-ranged the ship's own YDG-32 surface-to-air missiles, and mainly existed to provide early warning about incoming aircraft.

The ships' only anti-submarine detection system was a single sonar bulge in the bow; early models lacked any form of variable-depth or towed-array sonar. This severely constrained their effectiveness in anti-submarine warfare, limiting them to anti-surface missions unless the onboard helicopter was dedicated to searching for submarines.

Aircraft facilities

Early proposals for the Chŏndong-class featured a helicopter hangar on the stern, later moved amidships, but Jin Gi-tae opposed this feature on the basis that Chŏndong-class destroyers would mainly be operating close to shore and would have support from coastal aviation. Eventually, designers compromised on a single helipad with no hangar and only minimal support facilities. This allowed helicopters to temporarily land aboard Chŏndong-class ships to refuel, re-arm, switch out crews, and conduct basic maintenance, but did not allow the ships to support them during prolonged operations or in severe weather.

The helicopters used, GHJ-28s, were capable of conducting anti-submarine search missions, filling in for the ships' lack of variable-depth sonar, but in practice helicopters assigned to these ships were usually tasked with surface-search missions to locate targets for the ships' own heavy AShMs.

Service

During the Ummayan Civil War, Chŏndong-class destroyers played a prominent role in the Battle of the Aqaba Sea, with three destroyers in the 5th Surface Strike Group taking part in the attack: GCh-225 Nunbora, GCh-229 Bŏngae, and GCh-234 Dolpung. In total, the vessels fired 24 anti-ship missiles before turning back, but only landed three hits, according to Tiperyni records of the engagement. Poor coordination with AEW and maritime patrol aircraft contributed to this poor performance, which also convinced the Menghean Navy to revise its anti-carrier strike doctrine.

In the fighting that followed, two Chŏndong-class destroyers in the task force were lost. The Bŏngae succumbed to air-launched anti-ship missiles on the afternoon of the 14th, while the Nunbora (pictured at top) was damaged in the aerial attack yet remained afloat. Despite damage to the rear superstructure, it was able to retreat under its own power, but began experiencing engine problems overnight. During the early dawn hours of March 15th, it was struck by a torpedo from a Tiperyni submarine, and split in half directly beneath the funnel. As all ships in the formation were maintaining radio silence, and the captain had no time to send a distress signal, the ship's loss went unnoticed among the ships further ahead until 1103 hours when a patrol helicopter sent from the Dolpung failed to locate the Nunbora.

Later on the 15th, an Oyashimese destroyer arrived to pick up the survivors. This move was a major step in cementing Menghe-Oyashimese friendship. A monument to the Nunbora was built in the city of Hamyang in 2008, and the captain of the Oyashimese ship was invited to the unveiling ceremony, where he was greeted by the survivors.

The wreck of the Nunbora today lies within Ummayah's exclusive economic zone, but as a signal of gratitude, the Ummayan government in 2010 allowed Menghean salvage vessels to conduct dives over the ship's hull. The helm, recovered intact from the bridge, was brought to the surface and transported to the monument at Hamyang, after serving as a two-year temporary display in Gyŏngsan. The recovery team also claimed to have brought up the remains of Captain Ho Tae-su, cremating them for use at a Sŏngindan in his hometown of Hwaju. Some skeptics have questioned the official explanation of the recovery, charging that the description of Captain Ho "still standing at the helm" was unlikely and that the ashes used were false.

Ships in the class

Because construction began during the 1980s, ships in the Chŏndong class were named after weather systems, in keeping with ship naming conventions in the Menghean People's Navy. This practice persisted after the Decembrist Revolution. Subsequent destroyer classes, such as the Emil-si class destroyers and Haeju-class destroyers, were instead named for cities.

Ship numbers marked with an apostrophe (*) are of the Chŏndong-II subclass.

Hull number	Name	Sinmun	Meaning	Launched	Commissioned	Status
GCh-218	Chŏndong	천동	Thunder	19 December 1982	17 April 1984	Museum ship 2015
GCh-220	Hoeuri	회우리	Whirlwind	24 November 1983	11 February 1985	Scrapped 2017
GCh-222	Mulgyŏl	물결	Wave	12 March 1984	7 October 1985	Scrapped 2016
GCh-223	Pungrang	풍랑	Storm	6 January 1985	23 August 1986	Active
GCh-225	Nunbora	눈보라	Snowstorm	30 September 1985	11 November 1987	Sunk 2005
GCh-226	Noesŏng	뇌성	Thunderclap	14 August 1988	27 December 1989	Scrapped 2017
GCh-227	Ubak	우박	Hail	13 May 1989	1 September 1990	Active
GCh-228*	Sona-gi	소나기	Sudden rain	20 February 1991	5 October 1992	Active
GCh-229*	Bŏngae	번개	Lightning	21 November 1991	4 July 1993	Sunk 2005
GCh-230*	Kŭn-bi	큰비	Heavy rain	13 March 1993	12 September 1994	Active
GCh-231*	Ilchul	일출	Sunrise	14 June 1993	14 February 1995	Active
GCh-232*	Ho-u	호우	Torrential rain	4 September 1996	12 March 1998	Active
GCh-234*	Dolpung	돌풍	Squall	15 December 1997	22 June 1999	Museum ship 2014

See also

• Emil-si class destroyer
• Yŏngbŏk-class frigate