Kim Shimin-class destroyer

The Kim Shimin-class destroyer (Zhenian: 김시민급 구축함) is a line of Zhenian-built,  primarily in service with the Republic of Zhenia Navy. Intended to replace the significantly aging Changan-class destroyers that had been in service since the late 1960s, it has been hailed as the "future main force of the Zhenian Navy". The name of the class comes from Kim Shimin, the eighth Chancellor of Zhenia during the Third Zhenian Republic. Built around a multi-mission design, it is expected to primarily fulfill the role of, although its weapons and sensors layout also suggests significant capabilities in and even long-range surface strike, a role previously assumed by cruisers.

Due to its significantly larger size compared to previous destroyers as well as the roles it fulfills, some consider the class as, although they are formally categorized by the Republic of Zhenia Navy as destroyers. While the Republic of Zhenia Navy initially anticipated to field 72 of such ships by 2040, the overall plan, amid budgetary concerns, has shifted to fielding 48 ships, including both Batches I and II, by 2040. Instead, it is expected to be complemented by the Hansan-class frigates and improvements made on the Zhuhae-class destroyers.

Development and production
While the Changan-class destroyers provided fleet air defense coverage and occasionally performed flagship roles for the Zhenian Navy from the late 1960s and onward, the platform itself was clearly showing its limits. A line of interim destroyers, at the form of the Zhuhae-class, was built in the early 1990s in vain, although the process of constructing the Zhuhae-class provided crucial technical lessons on the construction of a new line of guided missile destroyers. An improved design that was based off the Zhuhae-class, addressing issues on propulsion and capacity to expand to counter future threats, was proposed by a consortium of Zhenian shipyards led by Jinmu Heavy Industries as a permanent replacement of the Changan-class destroyers, but were rejected in favor of a near-complete redesign that later became the Kim Shimin-class proposed by a consortium of the Signus Marine Group and Hanshin Heavy Industries, winning the contract in 2000: while Signus Marine Group was decided as the primary contractor, it were Hanshin Heavy Industries that had supplied more of the systems comprising the ship.

Among the many differences it had with its predecessors, the Kim Shimin-class' most visible difference from its predecessors includes the introduction of integrated masts built through radar-absorbing composite materials, a significant leap from the 'cluttered' superstructures of its predecessors. While a design containing phased array radar antennas, like the Zhuhae-class, were also considered, they were rejected in favor of the reinforcement and enlargement of the integrated mast. Vertical launch arrays, carrying assorted missiles in a grid arrangement, were also used more widely in the Kim Shimin-class, with dedicated anti-ship missile launchers vanishing starting from the Batch I vessels. Altogether, what became the Kim Shimin-class was focused significantly on survivability in contested waters as well as significant leaps in overall combat capability by integrating revolutionary technologies that were developed alongside the course of its development.



The first ship of its class, the ZNS Kim Shimin, was launched in 2003 in the Signus Marine Shipyards in Shinhang. Extensive testing and demonstration of systems by the Zhenian Navy had resulted in a number of small changes in the ship, including the adjustment of space allocated to crew quarters following assessments on the pressure of automation to the crew. While some of the newer systems implemented on the ship class, including all-electric propulsion that was the first for a ship of its size, initially became problematic in the early phases of testing, it were mostly solved by the time the ship was introduced to the Navy's service in 2005. Since then, the class has been built in Signus Marine Shipyards in Shinhang, where up to four were being constructed simultaneously in different phases at one point.

Upgrades and future development
With the Navy announcing plans to acquire up to 50 of such destroyers by 2035 and some ships expected to see service until 2070, plans for upgrades at an attempt to catch up with future battlefields and doctrines have already been envisioned. The Kim Shimin-class is expected to receive system updates set to enable the implementation of future characteristics in the combat system, including the integration of armament and information prioritization. Upgrades in electronics and software have contributed to additional reductions in radar signature as well as improvements in data processing procedures aboard the ship. Improved anti-submarine warfare suites, electronic counter-countermeasure (ECCM), a data backbone based on internet protocols among other upgrades have been implemented to existing ships, while also becoming default characteristics for later ships of the class.

A mid-life upgrade for Batch I vessels in the mid- to late 2020s in order to ensure their combat effectiveness over the course of its lifespan, set to include many of the features that are planned for future Batch II vessels, are currently being planned. Details surrounding the mid-life upgrades include the implementation of the currently in-development Skyguard II in the place of the existing SkyGuard CIWS, expansion of the aft VLS cells to accommodate additional missiles, improved (BMD) capability and further automation, although the exact details regarding scheduled mid-life upgrades remain unknown. There are estimations that the first Batch I vessels with completed mid-life upgrades are expected to roll out in 2026.

Armament




Designed to be considerably larger than its predecessors, particularly the Zhuhae-class, the primary armament of the Kim Shimin-class are an array of missiles carried in the 112 } (VLS) cells - 64 cells forward and 48 aft. Although the length of the 112 cells are equal at 8.1 meters, the 64 forward cells normally carry surface-to-air missiles, some of which are quadpacked, while the 48 aft cells carry an array of ordnance ranging from anti-ship cruise missiles, land attack cruise missiles and missile-launched anti-submarine torpedoes. Thus, it is considered one of the most heavily-armed vessels of its size within RZN service, dwarfing the Zhuhae-class, which carries ordnance over 96 VLS cells, hence earning the nickname "battery of the sea". Future vessels are expected to see the 48 VLS cells to be lengthened to around 9.3 meters and its diameter increased by at least 20%, most likely in order to accommodate, although it has not been yet specified if such expansions would mean fewer missiles as a whole.

In addition to its 112 VLS cells, it is also equipped with 16 VLS cells near the center of the ship, dedicated entirely to anti-ship missiles. Although anti-ship missiles can be stored and fired from other VLS cells, the 16 dedicated cells form the primary core of the ship's anti-ship capabilities. Primarily aimed for the operation of the larger and supersonic SSM-800 Thunderbolt, the sites of the anti-ship missiles can be swapped with more conventional subsonic missile launchers, although the Republic of Zhenia Navy has insisted upon maintaining VLS cells dedicated to supersonic missiles.

The Kim Shimin-class is equipped with a 127 mm/L62 naval gun, the same gun used on the Zhuhae-class, primarily used for close-range anti-ship warfare and extended-range fire support when needed. Rocket-propelled or GPS-guided glide munitions have also been experimented at an attempt to increase the gun's range and accuracy over long distances, which are being experimented as of 1610 AC. Point defense systems aboard the ship include the SkyGuard CIWS, consisting of two 30 mm Gatling gun and a missile launcher containing 21 short-range surface-to-air missiles, as well as a total of four 20 mm chainguns at an attempt to counter suicide attacks from boats on littoral waters. The SkyGuard CIWS, alongside its array of surface-to-air missiles, form a key component of the ship's multi-layer defense network.

Aircraft and boat features


The Kim Shimin-class is capable housing up to two full-size maritime within its hangar, as well a large aviation deck in the aft hull. Its aviation deck is 15% larger than its predecessors, with claims that it was aimed to accommodate a number of drones in addition to manned helicopters. It is further equipped with a GPS-based ship-landing assist system (SLAS) and a recovery, assist, secure and traverse (RAST) system to facilitate the operation of rotary-wing aircraft aboard the ship. Boats are handled within a stern mounted boat hangar with ramp. The boat hangar's stern location meets high sea state requirements for boat operations - a specific requirement that had been made by the Republic of Zhenia Navy, which intended to operate the vessels partly in contested waters.

Combat system


The combat system aboard the Kim Shimin-class, built to be similar to that on the Hansan-class, utilizes commercial-off-the-shelf technologies and components to increase the system's overall performance, implementing advanced data processing techniques and equipment that have altogether accelerated the process by hundreds of times compared to previous-generation systems. The has also been modified to include a common display system at the center of the bridge, allowing for the commander to identify data and personnel of each area directly, a step away from the specialization previously emphasized on existing command information centers. The combat information center is further defended with bulkheads and walls that protect the center from not only shrapnel, impact and heat but also electromagnetic waves, noise and vibration, significantly lowering the probability of the ship's neutralization in event of an attack.

The command and control system of the Kim Shimin-class, both as a measure to increase its survivability in the event of an attack and to enhance its capacity, is relatively decentralized. A set of modular enclosures spread across 12 well-defended shelters in the ship collectively store the onboard computers, while each of the onboard computers in their respective enclosures form a network with several backup chains, network-wise being connected to one another. Thus, any one of the twelve enclosures around the ship can assume the function of other enclosures when one is down or damaged, as long as data concerning the function are received into the enclosure. All enclosures and shelters are protected by higher standards than the combat information center, thus minimizing the chances of system neutralization if the ship is hit.

In addition to the common display system, all ships built as Batch 1B or later are on default equipped with a central projection system and console as well as a tactical situation awareness software, which fuses data from the ship's sensors and geographical data to display the surrounding topography and target locations real-time. The display systems are expected to be upgraded with 3D holographic projectors in Batch IB and Batch II ships starting in 1613. The same ships are also expected to be equipped with cooperative engagement capabilities, sharing target data with nearby ships via datalink and allowing nearby units to assume guidance of missiles launched from the ship: this characteristic is expected to enhance the ship's over-the-horizon combat capacity even further, expected to be used in synergy with nearby (AEW&C) aircraft.

Radar, sensors and electronics
A considerable portion of the ship's radars and sensors are mounted on the Hanshin Heavy Industries Phased Array Integrated Mast (PAIM), at an attempt to install sensors on the aircraft with minimal impacts to radar cross-section and survivability. Sensors mounted on the integrated mast include four S-band multi-functional (AESA) radars, X-band radars,  (IRST) facing all four directions, electronic warfare suites, panel-type VHF/UHF antennas, fixed IFF sensors and satellite communications (SATCOM) antennas, although some panel-type sensors, including datalink sensors and select electro-optic (EO) sensors, are also integrated into the ship's superstructure. The integration of multiple sensors into the mast altogether has resulted in the reduction of zones not covered by the ship's sensors, as well as increased situational awareness and coverage of the surrounding environment.

In addition to the integrated mast, the ship is equipped with a bow hull-mounted sonar as its primary submarine sensor. Its hull-mounted sonar is a significant leap from that mounted on the Zhuhae-class, being significantly larger and heavier: there are estimates that it has almost double the detection range and resolution compared to that on the Zhuhae-class. It has additional deployment ports for and multi-functional, increasing the ship's underwater coverage. The sonars together comprise a multi-static sonar system that further increases the ship's long-range precision submarine detection capacity.

Propulsion and power system
The Kim Shimin-class is one of the first large surface ships in the Republic of Zhenia Navy to use an system. Dubbed the Integrated Power System (IPS), it is an improvement from previous power systems in that the gas turbine is directly coupled to the electrical generator, which is then linked to the electric motor that moves the propeller shaft and also directly provide electrical power needed to operate the ship's systems. Implemented into the Kim Shimin-class to cater to the increased electrical demands from the ship's combat systems as well as to provide adequate power capacity to allow for future expansion, the integration of the system has provided far greater amounts of electrical power compared to other ship classes of similar size.

The ship's integrated electric propulsion system start from two Hanshin Motors GTM-4500 turbines located near the center of the ship, which each provide 35 megawatts of power that is then converted into electricity in four separate electrical generator. The power circuit of the ship deviates from the generators into two - one branch is directly connected to the two induction motors connected to each propeller shafts directly, and the other is linked upwards to power the ship's combat systems. An auxiliary power unit, consisting of an additional diesel generator separated from the ship via a number of watertight bulkheads, provides emergency power if the turbines and generators are damaged - the emergency diesel generator is estimated to provide around 45% of the total power capacity provided by the integrated electric propulsion system in normal circumstances.

The all-electric propulsion system altogether moves induction motors linked to the propeller shaft directly, without transmissions and other complicated gears found on its predecessors. While initial concept demonstrators included an underwater discharged waterjet system for increased speed within littoral waters, they were later axed out in favor of more conventional propeller shafts. Planned upgrades, starting from later Batch II vessels, include the replacement of the induction motors with a set of permanent magnet motors, which were expected to provide further acoustic signature reductions and increased efficiency compared to existing induction motors. The implementation of permanent magnetic motors is expected to increase the ship's cruising speed from the currently estimated 30+ knots to around 32 knots.

Survivability


Following the general trends of Zhenian ships built since the 1580s AC, the Kim Shimin-class has actively attempted to implement stealth configuration in the ship's overall design. Its usage of integrated masts as well as the building of most sensors directly into the ship's superstructure rather than sticking them out, concealing of chimneys in the smoke stack and conventional missile launchers among other features have all intended to decrease its (RCS) as a whole. The hull of the ship features an enclosed bulbous bow that conceals previously exposed points around the area, including anchor chains, mooring points and other equipment. Due to such attempts, the ship's radar cross-section, although its exact details are a closely-guarded secret, is relatively small considering the size of the ship, with rough estimates that it is comparable to a 1,000-ton fishing boat - almost one tenth of the ship's actual size. Such stealth characteristics have also contributed to the reduction of noise, infrared and electromagnetic radiation signatures of the ship, in addition to significant RCS reductions.

The Kim Shimin-class destroyer has implemented blast-hardened bulkheads at an attempt to minimize ship damage in the event it is hit by missiles or torpedoes. While they are nowhere near a permanent solution to ensure the ship's survivability, the blast-hardened bulkheads can reduce the impact from severe attacks by which many existing ships would have sunken. They altogether attempt to contain the ship's damage within the compartment. Sensors implemented into parts of the bulkheads, most notably the Maritime Fire Detection System built by Li-Jien Dynamics, work in hand with the ship's automated fire suppression system, which minimize the chances of ordnance explosions within the ship in events of fire or being hit.

At an attempt to increase survivability, it is also equipped with (ESM),  (ECM), an electronic warfare suite directly linked to its AESA radar system, decoy launchers and chaff dispensers among other countermeasures.

Batch I
Batch I ships of the Kim Shimin-class refer to the first 24 ships that was introduced to Zhenian service in the 1590s and 1600s AC. They are further divided into Batches IA and IB, each batch consisting of 12 ships. Batch IB ships feature smaller improvements over Batch IA vessels, including improved combat interface, the replacement of select antennas in the superstructure, integration of additional missiles among other features. As of 1610 AC, all Batch IA ships have been upgraded to Batch IB standards.

Batch II
The Kim Shimin-class Batch II, also known as the Han Jisung-class after the first ship of the new batch, is set to be a major upgrade in the existing destroyer platform, with significant improvements across various components. Although sporting a similar propulsion system with the previous batch, the Batch II ships are set to be powered by, enough to provide power capacity for future upgrades in its sensor suite and armaments, hinting for the introduction of and. Its 48 aft VLS cells are also expected to be lengthened further to carry longer and heavier ordnance, with many suspecting that they are aimed for ship-launched ballistic missiles and hypersonic glide vehicles. The first of its class, the ZNS Han Jisung, rolled out in August 27, 1610 AC and is expected to be introduced to the Republic of Zhenia Navy in 1612.