Chunchŏn-class frigate

The Chunchŏn-class frigates (Menghean: 春川級外層護衛艦 / 춘천급 외충 호위함, Chunchŏn-gŭb Oechung Howiham) are a class of guided missile frigate built in Menghe. Developed as successors to the Yechŏn class, they share the same battlegroup escort capabilities but are also designed to undertake coastal bombardment and anti-shipping missions. As of 2018, there are eight Chunchŏn-class frigates in service with the Menghean Navy, as well as three operated by Azbekistan and two operated by Ummayah.

Development

The Menghean Navy ordered design work on a new frigate class in the mid-2000s, not long after the breakdown of relations with Innominada. Because the two countries shared a coastline on the South Menghe Sea, this development raised the need for naval operations along an enemy-controlled coast.

As such, the Navy's procurement office required that the new ship be able to conduct coastal bombardment as effectively as the larger Haeju-class destroyer. The reasoning behind this decision held that because Menghean doctrine required that frigates be relatively inexpensive but well-armed for self-defense, an improved frigate class would be able to defend itself against anti-ship missiles and would allow the more expensive Haeju-class destroyers to stay further back. The Nunbora-class destroyers, pressed into the coastal bombardment role after becoming obsolete in the anti-shipping role, were also nearing the ends of their useful lifespans during this period, and the Navy hoped to use the new frigate class as a better-protected one-for-one replacement.

Along similar lines, the Navy required that the new class be better-equipped for anti-shipping missions. The Chŏndong-class destroyers had proven effective in naval combat during the Ummayan Civil War, and Menghe hoped to use later batches of this frigate class to replace them. The YDH-29 Chŏngryong missile, still in development at the time, would serve as the main armament. One early blueprint, marked Plan 84, carried eight forward-facing missile boxes on either side of the bridge like the Chŏndong class, but the final design mounted the anti-ship missiles between the bridge and the funnel because the launch box's exact dimensions were still unknown and an open deck space would also make it easier to refit the ship for other missile options.

These requirements caused some debate in the Navy, as more conservative officers viewed them as a form of mission creep: as initially envisioned, HO-type frigates (Oechung Howiham, "outer-layer escort ships") were supposed to specialize in the battlegroup defense role, sacrificing all capabilities not directly relevant to this mission in order to minimize cost and reduce the loss in capability from a sinking. Advocates for the expanded ship concept argued that the new capabilities required relatively little space, cost, and mass, and coincided with the baseline HO hull's demands for a high-speed, low-cost ship with good self-defense capabilities.

Navy design teams ultimately produced four competing designs for the new frigate project. Plan 84, mentioned above, had forward-facing missile launch boxes, and was eliminated early on. The initial favorite was Plan 87, which was 142 meters long with a taller superstructure, but conservative officers managed to block it on the basis that it was too large for the HO escort role. Its size would have also required modifications to the drydocks at the Gyŏngsan Songsu-do Shipyard. Instead, the Navy opted for a proposal designated Plan 85. This version had a lower "flush deck" hull, more like the Yechŏns, while retaining the same armament and capabilities. Plan 87 did, however, provide design experience for the Insŏng-class destroyers which followed later in the decade.

The first Plan 87 warship, named HO Chunchŏn, was laid down at the Kimhae Naval Yard on November 8th, 2010. It entered service on December 29th, 2013, after construction was rushed through the Yusin week festival. Chunchŏn and her sister ship Myŏngju were both completed in time to see service during the Innominadan Crisis, supporting landing operations off the Innominadan coast at the end of the year.

Characteristics

Propulsion and machinery

The Chunchŏn-class frigates use a CODLOG powerplant with two electric motors and two LM2500+ gas turbines, split across two propeller shafts. The electric motors use energy from four Taesan T4KJ diesel generators, each producing 4000 kW of electricity. In addition to driving the ship's powerplant, these diesel generators also power the ship's systems, and any combination of the four can be run at once to provide the amount of power needed. Three of the four diesel generators are mounted in a forward machinery room under the bridge to distribute propulsion equipment and enhance survivability, though because the aft generator is in the same compartment as both electric motors and both transmission units, a hit to that section would still immobilize the ship.

All machinery components are enclosed in sound-proof capsules and mounted on vibration-absorbing rafts, which makes the frigate especially quiet when running in electric mode. A prairie-masker air valve system further reduces cavitation and machinery noise.

Gun armament

While the Yechŏn class carried a 76mm dual-purpose gun forward, the Yechŏn is armed with a 130mm HP-130/1 Type 03 gun turret. This system has a rate of fire of 30 rounds per minute, and fires from two 20-round carousels at the bottom level of the hull, well below the waterline. It can fire programmable time-fuse shells, as well as point-detonation contact-fused shells, laser-guided shells, and Chŏl-u cluster munition shells. With a rocket-propelled long range shell, it has a claimed maximum firing range of over 100 kilometers.

Self-defense gun armament comes in the form of two GBM-23/5 Dungji CIWS mounts. This is the same number of guns as the Yechŏn class, but they are arranged in a fore-aft position over the bridge and helicopter hangar. This placement gives better coverage, with no blind spot forward and overlapping coverage on a 90-degree arc to each side. The "Dungji" variant of the mount carries sixteen YDG-61 anti-air missiles on each turret, complementing the gun for interception at greater ranges.

Despite its intended coastal role and despite the threat of Innominadan fast inshore attack craft, the Chunchŏn class does not carry dedicated autocannons for defense against small boats. Instead, standard practice is to rely on the GBM-23/5 guns, which have a reduced rate-of-fire setting for use against surface targets. The ships are fitted for but not with five 12.7mm heavy machine guns, with one pintle mount on the bow and four more flanking the bridge and the helicopter hangar. After the Innominadan Crisis, these are almost always left empty.