Haeju-class destroyer
| File:DDG Haeju.png DDG Haeju as built, in the "Haeju-I" configuration
| |
| Class overview | |
|---|---|
| Name: | Haeju class |
| Operators: | Menghe |
| Preceded by: | Emil-si class destroyer |
| Succeeded by: | Insŏng-class destroyer |
| Built: | 2002-2014 |
| In service: | 2006-present |
| Planned: | 12 |
| Completed: | 12 |
| Active: | 12 |
| General characteristics Haeju-I subclass | |
| Type: | Guided missile destroyer |
| Displacement: | 8,300 tonnes fully loaded |
| Length: |
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| Beam: | 17.2 m |
| Draught: |
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| Propulsion: |
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| Speed: | 32 knots |
| Range: | 6,000 nm (1,100 km) at 18 knots |
| Endurance: | 60 days (food) |
| Boats & landing craft carried: | 2x RHIB |
| Complement: | 290 |
| Sensors and processing systems: |
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| Electronic warfare & decoys: |
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| Armament: |
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| Aircraft carried: | 2 × GHJ-28 helicopter |
| Aviation facilities: | hangars and landing pad |
The Haeju-class destroyers (Menghean: 해주급 구축함 / 海州級驅逐艦, Haeju-gŭb Guchugham) are a class of twelve guided missile destroyer built in Menghe during the late 2000s and early 2010s. They originated as an effort to correct shortcomings with the preceding Emil-si class destroyers, but also took on a wider array of roles as multi-mission carrier escorts. Their modern design represented an impressive improvement, but concealed a number of internal flaws, including unreliable domestically built radars and an undersized combat information center. Some of these flaws were addressed by the Pyŏng'an subclass, comprising hull numbers 246 through 249.
New construction of Haeju-class ships ended in 2013, in favor of the larger and more capable Insŏng-class destroyer. As of July 2017, however, only five Insŏngs have been built, and the Menghean Navy plans to keep the Haeju class in service through the foreseeable future as a lighter complement to the new type.
Development
In 1998, Menghe commissioned its first "modern" guided missile destroyer, the DDG Emil-si. While the ship represented a major improvement over previous Menghean naval air defense capabilities, it was still hindered by a number of shortcomings, including poor RCS shaping, aging radar systems, and engine problems. For these reasons, construction was halted at four hulls, even though upwards of eight had been planned.
To correct for these problems, Menghean naval architects incorporated a number of new solutions into the emerging Haeju-class destroyers, seeking to address each of the problems that had emerged in their predecessors. Most visibly, the Haeju-class ships incorporated clean, enclosed superstructures built from a radar-absorbing composite material, a sharp contrast with the "cluttered" appearance of the Emil-si and Chŏndong classes. Moreover, at each corner of the forward superstructure were passive phased array radar antennas, greatly improving air search capability.
The Haeju-class also carried multi-mission hot-launch vertical launch arrays, which carried the missiles in a compact grid arrangement and could carry a variety of ammunition types. This represented a major improvement over the revolver VLS on the Emil-si class, which could only carry the YDG-60G SAM and were reportedly prone to jamming during rotation.
The Haeju-class destroyers also differed significantly in role. The Emil-si class DDGs were meant to specialize as air-defense ships, the defensive complement to the Chŏndong-class destroyers, and as such lacked significant surface-to-surface and anti-submarine weaponry. Descended from previous naval practice in the Federation of Socialist Republics, this approach resulted in less flexibility in small formations, especially carrier-battlegroups or small patrols. Breaking with this precedent, the destroyers of the Haeju-class were intended as fully multirole ships, capable of undertaking anti-air, anti-submarine, anti-shipping, and land-attack missions, depending on the needs of their formation.
Design
Layout
Despite superficial changes to the superstructure, the Haeju-class destroyers are fairly similar in layout to their predecessors. The aft helipad and hangars are somewhat roomier, leaving more space for landing and re-arming operations, a less-visible issue on the Emil-si. The Haeju-class also feature a distinct "break" in the superstructure between the funnel and the hangar area, where the aft VLS arrays are located. Overall, the Haeju-class has a lower superstructure, a design choice intended to further complicate enemy detection efforts. This move required the elimination of the secondary command bridge seen on the Chungsŏng and Emil-si, hindering the Haeju-class's ability to command other ships nearby as the flagship of a small surface-action group.
Vertical launch system
The main armament of the Haeju-class destroyers is a new, multi-mission vertical launching system, with eighty cells in total. These are split between two launch arrays, one forward and one aft. Each array consists of four 10-cell units each sharing a central vent for missile exhaust. Because they are located over the propeller shafts and between the engine rooms, the aft VLS cells are only 6.1 meters deep internally, and cannot accept certain missile types.
The introduction of multi-mission cells greatly improved the Haeju-class's flexibility, allowing the ships to be armed for anti-submarine, anti-aircraft, anti-shipping, or land strike scenarios, or a combination of the above. Available missile types include:
- YDG-64 SAM (quadpacked)
- YDG-62 SAM
- YDG-60N SAM (forward only)
- YJJ-52 land-attack cruise missile (forward only)
- YJJ-51 land-attack cruise missile
- YDH-29 anti-ship missile
- YDH-90 multi-stage anti-ship missile (forward only)
- YRDJ-4 anti-submarine standoff weapon
Other armament
On the foredeck, the Haeju-class ships carry a single 130mm, 70-caliber dual-purpose gun in a new reduced-RCS automated turret. This appears to be a lighter, more compact weapon derived from the twin 130mm turret on the Chŏndong-class destroyers. Its automated loading system can employ both single-unit rounds for anti-aircraft / anti-missile duties and separate-charge rounds for land-attack bombardment. In the latter role, it has been paired with new precision-guided and extended-range 130mm artillery shells.
For protection against incoming anti-ship missiles, the ship carries two "Sansin" (산신 / 山神, "guardian spirit of the mountain") Close-in weapon systems, one forward of the bridge and one above the helicopter hangar. These large, heavy mounts combine twin 30mm, six-barrel rotary cannons with two reloadable quad-missile cells for the YDG-61 SAM, and can cover all angles of approach, with overlapping coverage on the port and starboard 90-degree arcs. In addition to the 8 missiles on each mount, there are 32 more in an automated reloading assembly underneath the deck.
For anti-submarine operations, the Haeju-class carry two RBDJ-21/12 rocket-propelled depth charge projectors forward of the bridge. In addition to guided anti-submarine depth bombs, these are capable of projecting sonar-jamming rounds to distract enemy guided torpedoes. Stronger anti-submarine defense comes from two twin 400mm torpedo tubes, one on either side. While ready ammunition capacity is low, additional torpedoes can be brought up from a below-decks ammunition room and reloaded while the ship is underway, a capability not present on the Emil-si or Chŏndong classes.
For the most part, however, these ships would rely on their onboard GHJ-28 helicopters to detect submarines at greater ranges and engage them with homing torpedoes. Additional 400mm torpedoes from the ship's own magazine can be moved aft to the hangar for reloading between missions.
Radar and electronics
A much-noted feature of the ships upon their launch was the HR-5000 phased radar array set, with four octagonal panels around the superstructure. Initially, Menghe had planned to import SPY-1 radar sets from Dayashina, but the Organized States of Columbia blocked the deal in 2001, forcing the ship's designers to rush to develop a domestic radar system. The resulting PESA arrays were reportedly developed after consultation with Letnevian designers, though they are not a direct copy of any FSR system and appear to have been developed indigenously.
To provide further redundancy against system failure, the ships carry two additional 3D search radars: an HR-800 panel atop the main sensor mast, and an HR-1200 radome on a mast forward of the hangars. An HR-280 radome mounted atop the bridge provides long-range detection of surface targets, depending on atmospheric conditions. Separate radar systems provide missile guidance and artillery targeting.
Submarine detection measures include both a bow-mounted sonar bulge and a towed array sonar in the stern. Both of these are new-build Menghean systems, and are claimed to have much greater active and passive sensitivity than the hull sonar and variable-depth sonar on the Emil-si class.
Haeju-class warships also incorporate an improved electronic warfare system, with two ESM receiver antennas (designated J250) and eight ECM jamming antennas (designated J220) to detect and jam incoming radar-guided anti-ship missiles. A pair of 10-tube traversing projectors can create IR-smoke and radar chaff projectiles in the path of incoming missiles, or deploy parachute-slowed radar jamming units; the latter are effective at luring away anti-ship missiles with home-on-jam capability.
In a further improvement among Menghean warships, the Haeju-class destroyers also incorporate an integrated command-and-control system designed to streamline the coordination of the ship's weapon systems and those of other warships nearby. Operations are concentrated in a central combat information center incorporating digital displays for the ship's radar, sonar, and weapon systems.
Propulsion
Like many other Menghean warships of the period, the Haeju-class destroyers use a combined diesel or gas powerplant. Two diesel engines, each producing 5,000 shaft horsepower, enable greater fuel efficiency when cruising, while for high-speed combat operations the ship can switch to two 35,000-shp gas turbines, accelerating to speeds of just under 32 knots. One engine of each type is hooked up to each propeller shaft, but the turbines and diesel engines cannot be run simultaneously, a move intended to simplify gearbox construction.
Stealth measures
The Haeju-class follows a distinct reduced-RCS layout, intended to reduce the ship's radar signature and hinder detection. Compared to the Emil-si class, its superstructure has fewer exposed features, and reportedly makes use of either a radar-absorbent composite material or a radar-absorbent coating. The boat launches are concealed within enclosed hangars just forward of the hangar, and inflatable life rafts are stored in compartments just forward of the boat launches. Compared to the Emil-si class, which produced a distinctly large radar signature, Haeju-class ships are reportedly similar in radar return to a large corvette or fishing trawler, making it more difficult for enemy forces to separate them from other naval traffic.
The ships incorporate similar measures to reduce their infrared signature, with an air-mixing system installed within the funnels to cool down the engine exhaust. In combination with defensive countermeasure systems capable of quickly deploying walls of chaff and smoke, this hinders detection by imaging-infrared cameras, whether on aircraft or certain anti-ship missiles.
Beneath the ocean's surface, these ships also incorporated a number of passive sound-masking systems, including water jets on the propeller blades to prevent cavitation and two rows of air valves capable of deploying a bubble curtain over the ship's aft hull. These muffle the sound of the ship's engines, hindering passive detection by enemy submarines. Menghean sources mention "general noise-reduction measures" taken within the engine rooms themselves, but do not specify whether this includes reduced-vibration mountings, as they do for other ships like the Jŏngdŏk-class frigates.
Evaluation
When the destroyer Haeju was unveiled to the public at her launching ceremony, both domestic and foreign observers were impressed by the ship's visible characteristics. In terms of RCS reduction, VLS integration, and general layout, it represented a major step upward from the Emil-si class guided missile destroyers, and appeared to be on par with some of the latest foreign destroyer classes. Questions remained, however, about the capability of its less visible onboard electronic systems.
Menghean news media, including official spokespeople for the Menghean Navy, have asserted that the HR-5000 PESA radar is "equivalent in capability to the SPY-1", but other sources have called this claim into question. Because it needed to be ready before the Haeju's fitting-out deadline, the system was rushed during development, and some foreign intelligence sources speculated that Haeju's panels covered empty placeholder arrays during the ship's first two years of service. Additionally, the two rear-facing panels are partially obstructed by the helicopter hangar, leaving an estimated 30-degree blind spot over the ship's rear arc. This angle can still be covered by the ship's other search radar systems, but at shorter ranges and with reduced capability.
Pyŏng'an subclass
Foreign analysts were apparently not the only ones critical of the Haeju-class's shortcomings. When the ninth ship of the class, GChY-256, was commissioned in 2012, it came with a rebuilt forward superstructure elevating the aft-facing radar panels higher above the deck in order to clear the hangar. Menghean news sources have stated that within the superstructure, the ship's CIC was expanded into the new space cleared by moving the aft radar arrays, and the data-processing capabilities were improved through the use of newer computers, though no photographs of the CIC room have been published.
Just as significantly, the radar arrays themselves were different, comprising flat rectangular antennas rather than protruding octagonal ones. These are domestically designed active electronically scanned arrays, developed under conditions of considerable secrecy and only unveiled to the public when the Pyŏng'an was commissioned. By cycling between different frequencies, these arrays are much less susceptible to interception and jamming, and have fewer failure points. It is believed that the Menghean Navy also used this design opportunity to correct emerging issues revealed by operational trials with the Haeju's phased-array system. State sources claim that the AESA system operates in the high S band and is capable of detecting and tracking stealth aircraft and stealth missiles, though this may only be possible at relatively small distances. The four vessels of this class were subjected to extensive trials and testing with this radar system, partly in order to iron out unanticipated problems so that a scaled-up system could be used on the destroyers of the Insŏng class.
To accommodate these changes, loaded displacement increased by an estimated 400 tonnes, and speed dropped modestly. Both scale-model tests and operational sea trials were used to assess seaworthiness in heavy seas, and found that the ships could still operate in high sea states and typhoon conditions despite the added weight higher above the waterline, in part because the AESA arrays are lighter than their predecessors.
The next three ships of the Haeju-class were built to the same standard, for a total of four hulls. In some sources, these are known as the Pyŏng'an subclass, after the first ship to be commissioned in this configuration; in others, including official Menghean Navy records, they are designated "Haeju II."
Ships in the class
Like their predecessors, the Haeju-class DDGs bear the hull code GChY for "Guided Missile Destroyer" and are named after cities.
Ship numbers marked with an apostrophe (*) are of the Pyŏng'an subclass.
| Hull number | Name | Gomun | Sinmun | Launched | Commissioned | Status |
|---|---|---|---|---|---|---|
| GChY-238 | Haeju | 海州 | 해주 | 16 August 2004 | 26 October 2006 | Active |
| GChY-239 | Anchŏn | 安川 | 안천 | 22 April 2005 | 8 June 2007 | Active |
| GChY-240 | Dongchŏn | 東川 | 동천 | 12 March 2006 | 21 February 2008 | Active |
| GChY-241 | Chŏlsŏng | 鐵城 | 철성 | 4 June 2006 | 1 September 2008 | Active |
| GChY-242 | Hwasŏng | 華城 | 화성 | 2 September 2007 | 18 August 2009 | Active |
| GChY-243 | Gyŏngsan | 勁山 | 경산 | 19 August 2008 | 15 March 2010 | Active |
| GChY-244 | Daegok | 大谷 | 대곡 | 15 January 2009 | 8 November 2010 | Active |
| GChY-245 | Jang'an | 長安 | 장안 | 10 April 2009 | 8 May 2011 | Active |
| GChY-246* | Pyŏng'an | 平安 | 평안 | 12 July 2010 | 6 September 2012 | Active |
| GChY-247* | Ranju | 蘭州 | 란주 | 18 March 2011 | 20 April 2013 | Active |
| GChY-248* | Bokju | 福州 | 복주 | 16 November 2011 | 11 October 2013 | Active |
| GChY-249* | Yŏng'an | 永安 | 영안 | 2 June 2012 | 19 May 2014 | Active |