Chŏndong-class destroyer

The Chŏndong-class destroyers were a group of fourteen warships built in Menghe during the 1980s and early 1990s. They are designed around anti-surface warfare, carrying a heavy main battery of eight YDH-23 anti-ship missiles and a HP-130/2 Type 82 twin 130mm main gun. Their anti-aircraft armament, however, is limited to short-range point defense, and their anti-submarine armament is also relatively weak. Ships of the class have no helicopter facilities, and are entirely reliant on land-based aircraft or aircraft from nearby warships for targeting.

Owing to their small size and lack of helicopter facilities, the Chŏndong class are sometimes described as frigates. A few foreign intelligence services have remarked that in terms of role, they more closely resemble large corvettes. The Menghean Navy officially classifies them as "missile destroyers" (Yudotan Guchugham), in contrast to the contemporary Yobu-class destroyers, which are classified as "escort ships" (Howiham).

Development

The Chŏndong class are direct successors to the Nunbora-class destroyers, which likewise carried heavy AShM and gun armament but had poor anti-air and anti-submarine capability. Menghean naval planners envisioned sending them out in groups of four, led by a Yobu-class destroyer, to launch coordinated missile strikes against enemy carrier battle groups.

Design

The design was primarily the work of Jin Gi-tae, the chief naval architect at the Naval Design 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.

The design went through several iterations, each time decreasing in tonnage. Even smaller versions were considered, sacrificing, for example, the aft surface-to-air missile mount. Other problems concerned the powerplant. Jin Gi-tae originally hoped to install gas turbine propulsion in a CODOG arrangement, for a high maximum speed and fuel-efficient cruising. Technological constraints, however, limited Menghe to the use of a steam turbine plant, which in turn was derived from that on the Yobu class.

Construction

The final iteration of the design, designated Plan 272, was approved for mass production by the MoND, with the first hull laid down in March 1982. Construction was carried out under conditions of considerable secrecy, with the final fitting-out conducted in the city of Wihae rather than Gyŏngsan where the drydocks were located. For this reason, Dayashinese intelligence officials originally labeled the destroyer as the Wihae class.

Construction work was complicated by Menghe's first nuclear test in November 1984, which officially placed Menghe in violation of the STAPNA agreement. Faced with an embargo with its few remaining trading partners, including Polvokia, Menghe encountered delays in securing key components for the hulls still under construction. Economic dislocation under Ryŏ Ho-jun's ill-conceived reforms also disrupted supply chains, even as the Navy fought to limit interference in shipyard operations.

At the same time, the worsening geopolitical situation led the Menghean Navy to launch the Second Emergency Shipbuilding Program, stepping up new orders of Chŏndong-class warships to confront the increasing risk of an enemy attack. The Gyŏngsan 2 drydock, originally intended for cruisers and large destroyers, was appropriated for Chŏndong construction, and the Kimhae Naval Yard took on additional orders. Some documents from the period suggest that the DPRM intended to build a total of 25 Chŏndong-class warships, more than any postwar destroyer class.

After the Decembrist Revolution, the Second Emergency Shipbuilding Program was slowed down, and the military budget was decreased. The eight ships which remained in various states of construction in 1988 were completed on a reduced schedule, and three additional ships were laid down after 1989, all of them at Gyŏngsan. Later construction included careful inspections for faulty parts installed during rushed building, and both Chŏndong and Swaejŏn were drydocked in 1989-1990 to identify and replace faulty parts and welds. The basic design, however, was not modified during this stage, though there was some discussion of building the last two ships with helicopter facilities.

Description (as built)

Main armament

As built, the Chŏndong-class destroyers carried a powerful forward-facing battery of eight YDH-23JG "Yusŏng" anti-ship missiles. A surface-launched derivative of the Letnian KSR-5, the YDH-23 follows a quasi-ballistic trajectory toward the target, climbing to an altitude of 25 to 30 kilometers before descending at a terminal speed of Mach 4. While it has a maximum range of 280 kilometers when air-launched (500 kilometers for improved variants), the surface-launched variant has a range of only 200 kilometers due to the loss of fuel while ascending through denser low-altitude air.

Readying these missiles for launch could take over two minutes, a longer time than on Letnian 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 30 degrees to either side of the bow, requiring the ship to face toward its target during the launch phase.

From the late 1990s onward, the Chŏndong-class destroyers were refitted with YDH-25 missiles as part of their mid-life overhauls. About half of the 14 ships in service had been refitted this way when Menghe dispatched the South Sea Fleet to take part in the Ummayan Civil War. Though it has a shorter range, a lower speed, and a smaller warhead, the YDH-25 can follow a sea skimming trajectory all the way to the target, making it harder to detect and intercept. Later Menghean variants of the YDH-25 also boast improved performance, including the ability to perform pseudo-random evasive maneuvers on the final approach.

Other armament

Gun armament consists of a single HP-130/2 Type 82 twin 130mm gun mount. This weapon system was designed specifically for the Chŏndong class, and boasts improved traverse performance and a higher rate of fire than the SM-2-1 mount on the Nunbora class. It is capable of engaging ships, land targets, aircraft, and incoming anti-ship missiles, using contact, timed, or proximity fuses. Special guided rounds and submunition rounds were also later introduced.

Close-range gun armament consists of four AK-630 CIWS guns, two on each side. The forward pair are slightly further outboard than the aft pair, allowing both mounts to fire directly aft. Combined with the superstructure layout, this arrangement also creates a blind spot in CIWS coverage at 15 degrees to either side of the ship's prow. Air defense over this arc depends entirely on the main gun and surface-to-air missiles.

The surface-to-air missile armament, like the gun mount, was designed specifically for the Chŏndong class. Originally, it consisted of two launch modules for the YDG-36 surface-to-air missile. Each module consists of an eight-box launch unit, plus 24 reload missiles stored below deck. Each mount can cover a 270-degree arc, resulting in full 360-degree coverage with overlapping coverage to either side. Each mount carries a combination of radar-guided and infrared-homing missiles, for greater redundancy against countermeasures, jamming, and poor atmospheric conditions, and each of the four radar illumination antennas can guide two missiles toward one target at maximum. Post-launch trials and operational service revealed that the YDG-36 had very poor accuracy and reliability, and during refits these mounts were replaced with the Subisu combined-gun-and-missile CIWS.

Anti-submarine armament consists of two three-tube 450mm torpedo launchers, one on either side of the forward funnel. Sources disagree on whether reloads are usually carried. Further aft are two RBU-6000 depth charge rocket projectors, which can also throw sonar decoys to distract incoming homing torpedoes. Because the ships lack any kind of variable depth sonar, they cannot detect submarines below the thermocline except at very short ranges, and their anti-submarine weapons are purely intended for self-defense.

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