Donghan-class corvette

The Donghan-class corvettes are a type of warship currently being built in Menghe for the Menghean Navy. Officially labeled "medium coastal destroyers" (junghyŏng yŏnan guchugham) in the Menghean Navy's ship classification scheme, they are typically regarded as large corvettes or small frigates in foreign sources. Ordered as a premature replacement for the Saebyŏk-class corvettes, and influenced by the sinking of GYS-231 Bŏmram during the Innominadan Crisis, they have much better anti-aircraft and anti-submarine capabilities than their predecessors, though these capabilities are largely limited to self-defense. To conduct their primary mission of shore bombardment, the Donghan-class corvettes sport a 130mm gun in a single turret as well as vertical and angled launch boxes for YDH-26 anti-ship missiles or SY-26 land-attack missiles.

Development

During the late 2000s and early 2010s, the Menghean Navy had built two classes of "coastal destroyers," the Saebyŏk-class corvettes and Taepung-class corvettes. These vessels were tasked with engaging Innominadan light craft and missile boats, bombarding coastal targets, and escorting short-range amphibious landings. In contrast to proper destroyers or frigates, they were given minimal anti-ship, anti-air, and anti-submarine armament, with both classes carrying no surface-to-air missiles of any kind as built. The original rationale behind this decision was that they would operate with the support of land-based long-range surface-to-air missile systems and dedicated anti-submarine corvettes, and that they should be made as compact and inexpensive as possible to reduce the cost of inevitable losses.

The Innominadan Crisis showcased the usefulness of the coastal destroyer concept, but also showcased its vulnerability. GYJ-231 Bŏmram, a Taepung-class corvette, was sunk on 7 October 2014 after a low-flying MiG-21 fighter engaged her with unguided bombs. Analysis of combat data from the ship's recording box revealed that her 2D search radar detected the range and bearing to the target, but could not generate an altitude reading, leaving the ship's 76mm and 23mm guns unable to engage. In early 2015, after analyzing a report on the sinking of the Bŏmram, the Menghean Navy cancelled the 13th through 16th Saebyŏk-class corvettes and announced plans to retire the existing ships ahead of schedule, primarily by selling them to other members of the Namhae Front.

The resolution of the Innominadan Crisis also led Menghe to re-evaluate the rightful role of coastal destroyers. Most of Innominada's light missile boats had been destroyed during Menghe's intervention, and the lion's share had been sunk by aircraft or helicopters rather than naval gunfire. With the movement of the front line, the Menghean Navy now faced a greater focus on controlling the Strait of Innominada, with amphibious combat along the shoreline a secondary priority.

The Menghean Navy responded by updating its coastal destroyer concept. The core requirements remained the same: a compact vessel with a 130mm gun and hangar space for a single GH-30 helicopter, capable of traveling at 35 knots, on a hull displacing under 2,500 tonnes. Beyond this, however, the coastal destroyer would need to carry at least 32 YDG-64 surface-to-air missiles for self-defense, along with a 3D multipurpose radar system capable of tracking targets effectively within the missile's range. Signature reduction was also a major design priority, as a smaller radar cross-section would help the vessel evade detection by mimicking the radar return of a small fishing boat. As with the preceding Saebyŏk class, the ship would operate close to friendly ports and deploy consistently in assigned areas, so range and endurance would be sacrificed in order to remain within cost and tonnage limits.

In 2018, the Menghean Navy began advertising a preliminary design under the label Plan 588. It appeared as computer-generated concept art and as a scale mockup. The initial version apparently sported no anti-submarine systems or sensors apart from a mine and obstacle avoidance sonar protruding under the keel. A revised model, Plan 588N, added a hull sonar, six 350mm torpedo tubes, and Manhwagyŏng-H torpedo decoy launchers. Given the lack of HŎ-3 Ryongorŭm anti-submarine rockets, a towed sonar array, or an ASW-capable helicopter, it appears that these systems are intended purely for self-defense against submarines operating in shallow coastal areas.

The first ship built to Plan 588N's design was laid down on 21 August 2019. In 2020 it was announced that the ship, still under construction, would bear the name Donghan, which at the time was still carried by a Chŏndong-class destroyer; independent analysts interpreted this as evidence that GY-217 Donghan and other early-model Chŏndongs would be retired by 2022 at the latest, to avoid a situation where two warships carried the same name simultaneously.