Insŏng-class destroyer

4-view of HJ-384 Insŏng as built
Class overview
Name:	Insŏng class
Builders:	Gyŏngsan Songsu-do Shipyard Chŏndu New Naval Facility
Operators:	Menghe
Preceded by:	Haeju-class destroyer
Built:	2015-present
In service:	2020-present
Planned:	12
Building:	9
Completed:	2
Active:	2
General characteristics Insŏng, as built
Type:	Guided missile destroyer
Displacement:	11,000 tonnes full load
Length:	180.3 m overall 167.9 m waterline
Beam:	20.4 m o/a 19.5 m w/l
Draught:	6.72 m to keel, full load
Propulsion:	Integrated electric propulsion 4 × LM2500+ gas turbine generator, 29,000 kWe each 4 × Samsan 6EY33LW diesel generator, 3,450 kWe each 2 × 60,000 kW electric motor
Speed:	35 knots
Range:	7,500 nm (14,000 km) at 20 knots
Boats & landing craft carried:	2 × RHIB
Complement:	31 officers 284 crew
Sensors and processing systems:	4 × AN/SPY-6(V)1 phased array 4 × S-band surface search radar 1 × Thales NS50 radar 4 × Nun-10 electro-optical sensor 2 × Hongmoja dual-frequency optical unit 1 × low-frequency hull-mounted sonar 1 × Ŭ-100D variable-depth sonar 1 × AN/SQR-19 towed array sonar
Electronic warfare & decoys:	2 × Jadan heavy jamming array 4 × Metturi ESM/ECM suite 4 × Chasip ESM/ECM suite 4 × Baram-2 chaff/smoke launcher 2 × Manhwagyŏng-H 2 × D-107 datalink
Armament:	1 × HP-130/1 Type 102 130mm gun Mark 41 Vertical Launching System (128 cells) 12 × YDH-28 anti-ship missile 2 × GBM-23/5 Bulkkot 2 × 2 350mm tube for YŎ-35/2 torpedo
Aircraft carried:	2 × GH-36 compound helicopter
Aviation facilities:	hangar landing area with hauldown device

The Insŏng-class destroyers are the newest class of large guided-missile destroyer built in Menghe. They are large, multi-mission warships designed to provide long-range area air defense for Menghean carrier battle groups and anti-submarine task groups. For this purpose, they sport a powerful radar and electronic warfare suite and a large magazine of surface-to-air missiles, including the long-range YDG-67. They also possess substantial anti-submarine warfare capabilities, and a high level of stealth, quieting, and infrared signature reduction.

The Menghean Navy categorizes the Insŏng-class vessels as "main-force escort ships" (juryŏk howiham), the same type as the preceding Haeju-class destroyers and Pyŏng'an-class destroyers. This role indicates that, in addition to serving as multi-role escorts for a large task force, they also possess the ability to serve as flagships for a small surface squadron. Official Anglian-language literature produced by the Menghean government describes them as destroyers or guided-missile destroyers. Due to their size and displacement, as well as the fact that they carry substantial onboard command facilities, some countries instead regard them as cruisers, and in any case they represent a substantial advance in capability over preceding classes.

Development

MoND requirement

The Menghean Ministry of National Defense formally issued a design requirement for a new class of guided missile destroyer in 2010, though independent design work on next-generation DDGs had already been ongoing for several years by that point. Though satisfied with the overall quality of the Haeju class, the MoND was interested in a larger surface combatant which could more effectively protect a wider area. Central to this design would be a new type of active electronically scanned array, superior in range and tracking capability to the PESA AN/SPY-1 of the Haeju class. A new design would also offer an opportunity for a wide range of more incremental improvements, such as improvements to electromagnetic and acoustic signature reduction.

The initial MoND design requirement included mid-range ballistic missile defense as one of the desired missions of the future destroyer class. From patrol boxes in the South Menghe Sea, this would allow them to intercept intermediate-range ballistic missiles fired from Khalistan or Maracaibo, as well as medium-range ballistic missiles fired from Innominada. This role declined in importance after the EIA assessed in 2012 that no major EC member states had ongoing IRBM development projects, and the Innominadan Crisis of late 2014 removed the possibility of Menghean DDGs intercepting MRBMs from off the coast of Innominada. As such, the final iteration of the design entirely omitted BMD capability, though a future upgrade could make these ships BMD-capable.

Plan 1242 and 1244

The first design draft for the new guided missile destroyer project, designated Plan 1242, was a "maximum" design which aimed to satisfy all requirements with minimal regard for cost or size. It would have displaced roughly 15,000 tonnes at full load, and would have carried the 37-RMA SPY-6(V)1 phased array radar in a four-face arrangement. A scale model of Plan 1242 was unveiled at a military press event in 2012, and several computer-generated models circulated on the internet in the years to follow.

In addition to Plan 1242, the Navy also requested medium-size and minimum-size entries for comparison. The medium-size slot was filled by the 13,800-tonPlan 1244, which incorporated most of the same core features as Plan 1242, but tried to fit them on a smaller hull by omitting features not essential to the mission requirements. The differences between Plan 1242 and Plan 1244 included the following:

• The 130mm main gun was replaced by a single 76mm gun atop a deckhouse.
• The two single 76mm guns forward of the bridge were replaced by countermeasure launchers.
• The 37-RMA SPY-6(V)1 arrays were reduced to 24-module SPY-6(V)4 arrays, resulting in a smaller and narrower upper superstructure.
• Both 64-cell Mk41 VLS groups were rotated 90 degrees, and the crew spaces alongside them were reconfigured.
• The underwater hullform was made finer, which also increased stability.
• The aft 23mm CIWs was replaced by a twin 35mm CIWS using the DGP-35-2 anti-air gun.

The reduction of the gun armament was a particularly contentious move, and the Menghean Navy justified it on the following rationale:

• A ship as large and expensive as Plan 1242 should not put itself at risk by closing to shore bombardment range against a parity opponent.
• The new guided missile destroyers would mostly be assigned to escort carrier battle groups and anti-submarine patrol groups, which, within Menghe's geostrategic environment, would mostly operate in the open ocean against other sea forces, giving the destroyers few opportunities to directly support land operations.
• In addition to the legacy Haeju-class destroyers, the Chunchŏn-class frigates and Saebyŏk-class corvettes also carried 130mm guns, allowing them to undertake naval gun fire support missions instead.
• The forward 76mm gun is able to double as a close-in weapon system firing guided ammunition, removing the need for a second CIWS mount forward.
• The use of smaller ammunition, and the reduction in the number of stored rounds, both reduced the necessary internal volume for magazines and ammunition handling gear.

The smaller radar array space was particularly important in reducing the amount of mass high above the waterline. Though the number of RMA modules on each face reduced from 37 to 24, Dayashinese engineers promised that the 24-module array would still be able to detect and track a Rafale-sized target at cruise altitude out to the radar horizon, with the main reduction in capability affecting ballistic missile tracking capability at extreme ranges and altitudes. With the MoND already rolling back the BMD requirement for these ships, the design team regarded these tradeoffs as acceptable.

Radar procurement

As early as 2012, Menghean naval designers began regular information exchanges with Dayashina, which was then beginning early work on the AN/SPY-6 radar family. Though still in development, the AN/SPY-6 was forecast to reach operational status by 2020, which was also the deadline for the commissioning of the first new destroyer. Menghe ultimately did not contribute to the AN/SPY-6's development, but it did secure a guarantee that Dayashina would make the AN/SPY-6 available for export to Menghe simultaneous with its availability to the Dayashinese Navy, along with information on the projected dimensions and power requirements of the antenna arrays and their supporting systems.

Simultaneously, Samsan Defense began work on a long-range AESA radar which would serve as a domestic competitor. While Dayashina had opted for the E/F band as a compromise, the Menghean Navy favored a D-band AESA for long-range search, as this would improve sensitivity against reduced-RCS fighter-sized targets like the Sieuxerrian Rafale. An I-band sector search and illumination radar would then convert these low-resolution D-band tracks into more precise tracks and provide missile guidance. In 2013, this program received the internal Samsan designation HR-2000.

The HR-2000 program had a promising start, but as development progressed it ran into a number of serious delays and barriers, especially surrounding the high-end electronics in the antenna elements. As late as early 2015, Samsan had yet to produce a working full-scale prototype array, and it was becoming clear that the HR-2000 would not be ready for delivery to shipyards by 2018. Rather than postpone orders and gamble on future breakthroughs, the MoND awarded Raytheon the contract for the SPY-6 units on the Plan 1244 destroyers in March 2015, and in June of that year, the keel segment for HJ-384 was laid at the Gyŏngsan Naval Yard with plans for a final design incorporating the SPY-6(V)4. The HR-2000 program was cancelled entirely the following year, though Samsan continued independent work on large L-band phased array radars.

Early construction

A mock-up of the Plan 1244 superstructure was first spotted at a coastal missile testing range in Ryangnam Province in 2014. This structure was likely used to test the new ship's electronics equipment, as final test work was still underway. Official state media at first suggested that the mock superstructure was intended for the Onju-class destroyer group, but based on clear differences in the superstructure and estimated measurements of the ship's size, independent analysts quickly concluded that it was part of a new class. This information was officially confirmed in May 2015.

The location of the test site stirred a great deal of discussion. The Menghean Navy had built test sites on land for decades, but usually in the blocked-off zone of the North Donghae Missile Range or at secret test areas in the northwest. The new test site, by contrast, was not only a short distance from Altagracia, but also clearly visible from the G76 expressway leading to the Juman Container Terminal and from civilian shipping lanes in Hwangsa Bay. Ostensibly, the Hwangsa Bay location was chosen to test the surface search radar's performance in an environment cluttered with civilian surface targets, but its proximity to Altagracia may have been a signal of strength to the Entente Cordiale states.

In 2017, the hull mockup fired surface-to-air missiles at a target drone over Hwangsa Bay, confirming that it was equipped not only with a full sensor suite but also with a fully operational vertical launch system. This suggested a further rationale for the chosen location: it allows the test site to provide air defense for Sunju, Tongju, Juman, and Dongchŏn, and guide long-range surface-to-air missiles into Altagracian airspace.

Design

Structure and survivability

The Insŏng-class destroyers are the first Menghean surface combatant class (i.e., excluding carriers, auxiliaries, and the hybrid Hasŏ-class cruisers) to surpass 10,000 tonnes displacement at full load, and their size alone made them a substantial source of national pride when they were introduced. As built, HJ-384 Insŏng had a full-load displacement of 13,930 metric tonnes, making her one of the largest destroyer classes in the world.

For the structure of these ships, the Menghean Navy opted for an all-steel construction, rather than using lighter and potentially stealthier composites. The primary consideration was cost: Menghe's military shipbuilding sector is more experienced working with steel, and introducing other materials could have delayed construction or harmed implementation. Steel construction also resulted in somewhat greater durability and damage resistance, especially when compared to aluminium, which is more prone to cracking under strain and which can disintegrate catastrophically in a large fire. Navy engineers also worried that more exotic composites, particularly untested ones, might degrade under prolonged exposure to the elements, and regarded steel as a lower-risk option for an already major ship project.

Many other design choices around the hull are intended to bolster survivability. Almost all of the decks and compartments below the waterline incorporate some form of double hull, with either void spaces or fuel tanks between the outer steel plating and the internal compartments. For the steel thicknesses used, this provides negligible protection against direct shell, missile, and torpedo impacts, but it does limit flooding from shrapnel damage and minor collisions.

Nine watertight bulkheads separate the ship's hull into ten major sections, with some of these bulkheads extending as much as two decks above the waterline. These major bulkheads consist of two steel plates separated by a half-meter gap, which consists of void space lined with Kevlar. In the event of a shell or missile impact, these bulkheads can protect the adjacent hull sections against spalling and shrapnel, and help damage control teams limit fire to one particular area. The bulkheads are also fully watertight at least up to one deck above the waterline, and can limit flooding from a nearby mine or torpedo detonation to the breached hull section. In addition to these major bulkheads, most of the individual doors and hatches throughout the ship can be firmly sealed to contain fire or flooding.

The configuration of the ship's propulsion system is also intended to increase survivability. The main machinery components are split across four compartments, reducing the likelihood that any single impact could completely immobilize the ship. The sprinting gas turbines are in the aft hull below the waterline, a fairly conventional location, but the main gas turbine generators are located one deck above the waterline, embedded in the superstructure under the forward funnel. This fully isolates them from flooding damage, and also reduces their acoustic signature. Directly beneath them are the main direct-drive electrical engines and two of the diesel generators. These paired propulsion units are located at the very sides of the hull, but they are separated by centerline compartments which can be sealed off, potentially limiting damage to one side of the ship. The aft diesel generators are under the aft half of the helicopter hangar, and are slightly above the waterline, which also isolates them from flooding and noise. In the event of catastrophic damage to all four amidships compartments, the aft diesel generators can still power the maneuvering thruster forward, allowing the ship to limp to safety at a speed of 6 knots. This capability proved vital in the recovery of HJ-388 Chilsan.

All major ammunition magazines, including the magazine for helicopter armament, are stored below the waterline, reducing the risk of secondary explosions from missile impacts. The aft bomb and torpedo magazine is connected to the hangar by a single ammunition elevator with blast doors at both ends, an innovation introduced on the Chunchŏn-class frigates. The only exceptions are small arms and ammunition lockers throughout the ship; 35mm shells in the aft CIWS mount; the ready ammunition carousel of the 76mm gun; and the two VLS missile farms, all of which are entirely above the waterline.

Sensors

The Insŏng-class destroyers are among the first operational warships to carry the AN/SPY-6 air search radar system, alongside the Dayashinese destroyer Maya. Specifically, they use the AN/SPY-6(V)4 variant, with four faces each comprised of 24 antenna modules in an octagonal array roughly 3.8 meters across. This radar uses gallium nitride (GaN) transmitters with greater output and state-of-the-art computers with greater processing power, resulting in a reported thirtyfold increase in sensitivity over the already capable AN/SPY-1D. The radar's exact parameters remain classified, but official Menghean Navy sources report that it is capable of detecting and tracking a Dassault Rafale out to its maximum cruising altitude limited only by the radar horizon, implying a range of perhaps 500 kilometers against a reduced-RCS fighter-sized target.

Because the AN/SPY-6 uses AESA technology, with nimbler beamforming capabilities, it can also augment its effectiveness by increasing its dwell time on small targets or distributing search time according to a set program. Furthermore, the AN/SPY-6 can divert some or all of its output to electronic warfare, either jamming I-band radar within a wide area or focusing a narrow beam of high-powered jamming energy at a particular target.

As designed in Dayashina, the AN/SPY-6(V)4 does possess the ability to detect and track ballistic missiles, though it is less sensitive than the 37-RMA AN/SPY-6(V)1 or the proposed 69-RMA maximum variant. The Menghean Navy cut ballistic missile defense from the Insŏng-class destroyers during the switch from Plan 1242 to Plan 1244, but the ships' onboard hardware and software are likely still capable of detecting and tracking intermediate-range ballistic missiles, even if the ships currently lack anti-ballistic missiles capable of intercepting them.

In addition to the high-power phased arrays, there is a Thales NS50 radome mounted high atop the main sensor mast. This radar spins at 15 or 60 RPM, though its AESA construction also allows it to dwell on possible contacts in the course of each spin to generate confirmed target tracks. It has a range of only 180 kilometers, inferior to the AN/SPY-6, but it is mounted a full 37 meters above the waterline, allowing it to detect sea-skimming missiles at ranges in excess of 30 kilometers. The AN/SPY-6 arrays have a radar horizon of about 20-25 kilometers against a sea-skimming target. The NS50 also operates in the I/J band, as opposed to the E/F band, complementing the main search radar.

Above the four AN/SPY-6 panels are four long phased array antennas. These are reportedly optimized for surface search. There is some speculation that they may be designed to exploit atmospheric duct effects in the active and passive mode to detect surface ships well beyond the normal radar horizon, much like the HR-280 carried by older Menghean warships. As of 2022, this has not been confirmed, and some sources report that these antennas may instead be long-range IFF interrogator antennas supporting the AN/SPY-6 system.

In the infrared band, the Insŏngs carry two Hongmoja electro-optical scanners, which rotate at 10 or 30 RPM. Each unit contains two cameras which can be set to different elevations. From 32 meters above the waterline, they can detect a sea-skimming target at roughly 25 kilometers and a small surface target at roughly 20, detecting incoming missiles even when the ship is operating under radio silence. The exact sensitivity of the Hongmoja system is classified, and given the characteristics of infrared sensors, it likely varies greatly depending on atmospheric conditions, but under ideal conditions the Hongmoja scanner is reportedly able to detect high-altitude fighter aircraft at short to medium ranges.

The anti-submarine sensor suite is modeled after the suite carried by the Hasŏ-class cruisers, with a Ŭ-100D variable-depth sonar and a Ŭ-109 towed array cable. These systems can be used independently or in combination, and the Ŭ-100D has both active and passive modes. The hull sonar is a large low-frequency active-passive spherical array, but it lacks the extended side-scan panels of the Hasŏ class. This gives the Insŏngs very capable submarine detection capabilities.

Electronic warfare and countermeasures

In addition to the secondary jamming function of the search radar, these ships carry two other electronic warfare systems. The first is the Chasip electronic warfare suite, which is made up of two passive ESM arrays and one active ECM array. Little public knowledge about this system is available, and it only appears on the Insŏng-class destroyers. Some analysts speculate that it may be optimized for matching lower-frequency radar bands, allowing it to jam certain airborne early warning platforms more effectively. Other sources believe it may instead be intended for jamming communications. The square Chasip antennas are located on the front, rear, and sides of the superstructure pyramid, in stacks of three.

The Metturi electronic warfare suite, on the upper mast, works in the E/F and I bands, and is primarily meant to defend against anti-ship missiles. In automatic mode, it autonomously identifies the emissions of missile seekers, categorizes them by type based on their emissions and other sensor input, and blinds them with a directed radio beam in the same wavelength and frequency, without the need for crew input. Because the Metturi system is high up on the ship's superstructure, missiles with home-on-jam capability may be seduced into overshooting the hull and superstructure, or would at least strike the upper sensor mast.

Four Bakjŏlgi countermeasure launchers, part of the Baram-2 family, are distributed around the superstructure to provide a final line of defense against anti-ship missiles. Each launcher consists of twelve 135mm tubes in a low-RCS composite shell shaped like a truncated pyramid. When deployed, these can fire chaff and smoke screens, infrared flares, and parachuting active radar jammers, which can further seduce home-on-jam missiles. THe number of external stowage bins suggests that at least 144 reload projectiles can be stored in ready lockers, not counting the 48 projectiles in the launchers themselves and any additional projectiles stored within the hull.

The ships also carry four Ori decoy launchers, which are located behind doors slightly forward of the aft VLS array. The Ori system fires a fast-inflating buoy with radar reflectors and heat emitters, which can seduce incoming anti-ship missiles or create a temporary false target for enemy surveillance radar. In addition to the four ready decoys, 16 reload canisters are stored within the hull near the launchers. The launch tubes themselves are locked in position to fire, but pivot 45 degrees away from the adjacent bulkhead to allow easier reloading.

The two Manhwagyŏng-H launchers are located on either side of the forward funnel, just above the RHIB bays. Each one can fire twelve active sonar jammers, which can seduce incoming torpedoes by creating an array of false targets and blocking out the noise from the ship's own engines. The Manhwagyŏng countermeasure is also reported to be effective against wake-following torpedoes which rely on active sonar.

Machinery

The propulsion system of the Insŏng-class destroyers uses a COGLAG configuration, or Combined Gas-Electric and Gas, with integrated electric propulsion linking the gas turbine generators and auxiliary diesel generators to the electric motors. The table below summarizes the type and power of the different powerplants and generators distributed throughout the ship.

Designation	Type	Designer	Output	Number
LM2500+G4	Gas turbine generator	GGE	35,000 kW	2
LM2500+G4	Gas turbine (geared)	GGE	33,600 kWe	2
6EY26LW	Diesel generator	Samsan	2,300 kWe	4

The two gas turbine generators in the superstructure, as well as the auxiliary generators throughout the ship, are connected to the propeller shafts by two Samsan S2328 electric motors. These are brushless DC electric motors directly coupled to the propeller shafts, with neither wire brushes nor transmission gearboxes contributing to noise. Combined with the fact that the gas turbine generators are located above the waterline, this results in very quiet operation while under electric power.

The ratings in the table and text assume standard ISO atmospheric conditions, and may therefore overestimate performance. In the tropical South Menghe Sea, where the Menghean Navy typically operates, ambient temperatures often climb as high as 40 degrees Celsius. Under these conditions, the shaft power of the LM2500+G4 turbine at full output can degrade as far as 25,000 kW, with the output of the gas turbine generators falling proportionally. Because the LM2500 is a proven platform based on mature technology, the Insŏngs are not known to suffer from powerplant reliability issues in tropical conditions, but a report compiled by the Ministry of National Defense in 2024 reported that they struggle to reach their top speed in hot weather.

Aviation facilities

Apart from the Hasŏ-class cruiser, the Insŏngs are the only Menghean warship class to support the Gyundoan-Han GH-36 Mulsuri in the anti-submarine role. The aft hangar has space for two GH-36 helicopters, typically the GH-36N, which has anti-submarine sensors and armament pylons on larger stub wings. Compared to the GH-28 seen on most other Menghean warships, the GH-36 has a longer range, a heavier payload, and moderately improved sensors, at the cost of greater length and mass. As a compound helicopter, the GH-36 can also cruise at 400 km/h and sprint at 450 km/h, allowing it to cover a larger patrol box in the same time frame as the GH-28 and respond more quickly to distant sonar contacts.

The munitions elevator and the aft magazine room are large enough to hold YDH-26 missile assemblies and their boosters. This allows the ship's helicopters to be fitted out for anti-shipping missions. The GH-36N is capable of carrying two YDH-26 missiles, one on each outermost pylon, not enough to overwhelm a warship with a modern surface-to-air missile system but enough to engage naval auxiliaries or missile boats. To attack small surface craft, the ship's helicopter can be loaded with YDJ-48 Salmusa guided missiles, unguided rocket pods, or 30mm gunpods.

On a more typical mission, the ship's GH-36N would be loaded with two to four YŎ-35/2 torpedoes and 42 sonobuoys. This is a comparable loadout to the DY-11DJ fixed-wing carrier-borne ASW aircraft, and double what the GH-28 ASW variants can carry.

To support landing operations in heavy seas, the Insŏng-class destroyers have two hauldown devices that run along tracks on the helipad. Once a helicopter has landed, the recovery plate slides forward along its tracks into the hangar, bringing the helicopter along with it.

Armament

The Insŏng-class destroyers are fitted with 128 Mark 41 vertical launch cells in two 64-cell arrays, one forward and one aft. All cells are strike-length. A state news report in 2020 listed the following "typical loadout," though actual loadouts may vary based on the mission in question:

• 16 × HŎ-3 Ryongorŭm anti-submarine rocket
• 64 × YDG-64, quadpacked (16 cells)
• 64 × YDG-67, quadpacked (16 cells)
• 64 × YDG-68 long-range surface-to-air missile
• 16 × YDG-69 anti-ballistic missile (in development)

In addition to the vertical launch cells, the Insŏng-class destroyers have twelve long angled box launchers between the funnels, the same arrangement seen on the Sŏnsan-class frigates. These are believed to carry YDH-28 or YDH-90 anti-ship missiles, though because they use the same missile storage canisters as the vertical launch cells, a variety of loadouts may be possible.

Gun armament consists of a single HP-130/1 turret forward, the same as on the Haeju-class destroyers and Chunchŏn-class frigates. This gun can engage aerial as well as surface targets, and is loaded from a magazine below the waterline. As with many other Menghean warships, the Insŏng class do not carry any specialized autocannons for engaging light surface craft; instead, this role is left entirely to the deck gun and the two 23mm CIWS mounts.

In addition to the HŎ-3 anti-submarine rocket, the Insŏng-class destroyers are armed with two twin 350mm torpedo launchers for close-range defense. These are reloaded from the same magazine as the helicopters. They are located behind protective panels on either side of the aft VLS block.

Propulsion

The Insŏng-class destroyers are fitted with an all-electric propulsion scheme, with two 60,000-kW direct-drive electric motors driving two conventional propeller shafts. At full throttle, they can achieve speeds of over 35 knots. At low speeds, these electric motors also allow for very quiet operation, reducing the probability of passive detection by submarines and reducing noise interference with the ship's own sonar systems. The two motors are also staggered across two watertight bulkheads, and separated by a third.

The generators for the electric motors and the ship's systems are distributed around the ship, resulting in a high degree of redundancy in the event of a missile or torpedo hit. The four 3450-kWe Samsan 6EY33LW diesel generators are split between three watertight compartments spaced at wide intervals, and the ship can power its sensors, EW suite, and life-support systems on two generators alone. The four LM2500+ gas turbine generators are located not in the hull, but in the superstructure, 5.7 meters above the waterline and in two spaced compartments surrounded by fireproof bulkheads. This arrangement provides maximum protection against flooding damage, and also results in greatly increased noise insulation: for optimized anti-submarine operations, the ship can run one turbine to power the electric motors and onboard systems, keeping all diesel generators within the hull shut off. All generator units are mounted on vibration-damping rafts.

A single retractable propeller unit under the forward VLS group provides auxiliary thrust in the event that both electric motor rooms are flooded, and also allows easier docking and maneuvering in port.

Protection and countermeasures

For any anti-ship missiles that slip past the ship's large SAM arsenal, the Insŏng-class destroyers are fitted with two GBM-23/5 Bulkkot close-in weapon systems, one above the bridge and one above the helicopter hangar. Interestingly, both are baseline Bulkkot models, rather than the Dungji model with YDG-61 surface-to-air missiles or the Subisu CIWS used on the Haeju-class destroyers. Some analysts interpreted this armament choice as a judgment that the YDG-67 active radar homing missile was more accurate than the YDG-61, which by 2020 is nearly two decades old and had relatively modest performance even upon its introduction.

An official press release unveiled in August 2020 stated that the Menghean Navy is working on "unconventional close-in weapon system options" for later ships of the Insŏng class, including railguns, directed energy weapons, and a stacked charge volley gun. The same press release stated that the existing mounts are designed to allow easy installation of new close-in weapon systems in refits.

Additional defensive countermeasures consist of eight Ori radar decoy buoy ejectors, four Baram-2 chaff, flare, and decoy projectors, and two Manhwagyŏng-H torpedo countermeasure projectors. Crates of reloads for all decoy ejector types are mounted on the deck.

Aviation facilities

The quarterdeck of the Insŏng-class destroyers contains a landing area and hangar space for two helicopters. While nearly all previous postwar Menghean large surface combatants used some variant of the Gyundoan-Han GH-28 Ppulsoeori, the Insŏng-class can carry the larger GH-36 Mulsuri, a compound helicopter with a pusher propeller. Compared with the GH-28, this helicopter has a faster cruise speed, longer range, and higher sonobuoy capacity, allowing it to patrol a larger area.

Operational service

Chŏngdo's world tour

The second ship in the class, HJ-385 Chŏngdo, embarked on a special world tour shortly after being commissioned into the fleet. As part of this voyage, she circumnavigated the globe traveling east, conducting pre-scheduled courtesy calls at a number of friendly ports along the way. She was accompanied by the underway replenishment ship Yŏngjŏng, but otherwise traveled alone, without a larger battlegroup.

Chŏngdo's voyage started in her namesake port city of Chŏngdo, which she departed on 30 October 2020 three days, after her commissioning ceremony. From there, she made stops in Donggyŏng, Nakazara, the Aijuku Islands, Inishmore, Avallone, Sayamota, Inisheer, Guacara, Kopanes, Selkiö, Satamansuu, Lappo, Puerto Alegre, Ao Mangkon, and Quẚng Phẚ, Sunju, and Chanam, before finally docking in Gyŏngsan for a thorough post-voyage maintenance check. During most of these port visits, Chŏngdo was partially opened to the general public for tours of her deck and some non-sensitive areas. At Nakazara, Avalonne, and Selkiö, Dayashinese, Glasic, and Hallian naval officers were given exclusive guided tours of the ship's interior and allowed to inspect onboard electronic systems.

The voyage also included a number of naval exercises, particularly with Dayashina and Tír Glas. En route from Inishmore to Avalonne, she conducted a rendezvous with the guided missile cruiser Banbha. At several points on her voyage, she also conducted more aggressive exercises, sailing near Sieuxerrian naval bases in Scintillement and Anglian naval bases in the St. George Islands. On the long voyage from Impor to Kopanes, she also sailed close off the coast of Anglia and Lechernt, Sieuxerr, and Sylva, staying outside of EC territorial waters but claiming innocent passage through the EEZ. This was the first time an armed Menghean surface warship had passed through any of these areas, or for that matter through the Maw south of Inisheer. In addition to signaling Menghe's resolve, these maneuvers also provided an opportunity for the Chŏngdo to test her sensor suite against Entente aircraft, surface ships, and submarines.

Itinerary of the Chŏngdo's world tour
2020-11-05	Departs from the city of Chŏngdo
2020-11-07 to 2020-11-10	Nakazara, Dayashina
2020-11-14 to 2020-11-16	Aijuku Islands, Dayashina
2020-11-29 to 2020-12-04	Inishmore, Tír Glas
2020-12-06 to 2020-12-13	Avallone, Tír Glas
2020-12-17 to 2020-12-20	Sayamota, Macchia
2020-12-21 to 2020-12-27	Inisheer, Tír Glas
2021-01-02 to 2021-01-04	San Janos, Federiko
2021-01-08 to 2021-01-15	Guacara, Idacua
2021-01-31 to 2021-02-06	Kopanes, Ostland
2021-02-09 to 2021-02-17	Selkiö, Hallia
2021-02-21 to 2021-02-25	Satamansuu, Uusimaa
2021-03-02 to 2021-03-06	Lappo, Hallia
2021-03-13 to 2021-03-20	Puerto Alegre, Republic of Innominada
2021-03-22 to 2021-03-23	Ao Mangkon, Argentstan
2021-03-25 to 2021-03-28	Quẚng Phẚ, Menghe
2021-03-30 to 2021-04-04	Sunju, Menghe
2021-04-08 to 2021-04-14	Chanam, Menghe
2021-04-17	Arrives at Songsu-do Naval Base

Ships in the class

As of December 31, 2020, there were two Insŏng-class destroyers in service, five in fitting-out, and four more under construction in drydock, with a twelfth and final ship under contract. There are rumors of future orders under negotiation, but as of yet, the Menghean Navy has ordered twelve ships in total. They are built by the Gyŏngsan Songsu-do Shipyard and the Chŏndu New Naval Facility. Because the latter facility uses covered drydocks, ships built there are only partially built up when launched, with the rest of the mast lowered in place by heavy cranes during fitting-out.

The Insŏng-class destroyers, like their predecessors, are named for Menghean prefecture-level cities. Not coincidentally, a number of them share names with planned or operational battleships of the Greater Menghean Empire. Insŏng and Hwasŏng were the names given to two cancelled super-heavy battleships, and Chŏngdo and Sunju were the names of the two Chŏngdo-class battleships. With the announcement of Wŏnsan as the name of the last planned destroyer in 2020, some observers have noted that there are only a few remaining prefecture-level cities that do not yet have an active destroyer named for them, raising speculation that the Menghean Navy might alter its naming scheme at some point before mid-century.

Number	Name	Mengja	Builder	Laid Down	Launched	Commissioned
HJ-384	Insŏng	仁城	Gyŏngsan	2015 06 24	2017 05 11	2020 05 03
HJ-385	Chŏngdo	青島	Chŏndu	2015 09 07	2017 08 14	2020 10 27
HJ-386	Hyangchun	香春	Chŏndu	2016 12 10	2018 11 11	2021
HJ-387	Chanam	叉南	Gyŏngsan	2017 05 17	2019 02 20	2021
HJ-388	Chilsan	漆山	Chŏndu	2017 08 19	2019 05 31	2021
HJ-389	Jinyi	晉義	Gyŏngsan	2018 09 27	2020 08 17	2022
HJ-390	Sangha	商河	Chŏndu	2018 11 15	2020 08 20	2022
HJ-391	Sunchang	淳昌	Chŏndu	2019 06 04	2021	2023
HJ-392	Hwasŏng	華城	Gyŏngsan	2020 05 26	2022	2023
HJ-393	Taean	泰安	Chŏndu	2020 08 22	2022	2024
HJ-394	Gŭmchŏn	錦川	Gyŏngsan	2020 10 26	2022	2024
HJ-395	Wŏnsan	遠山	Gyŏngsan	2022	2024	2025

See also

• Yamazaki-class guided missile cruiser