JCh-4
| JCh-4 | |
|---|---|
| File:MinChong 4 new.png Main variants of the JCh-4 with the year they entered service. | |
| Type | Medium Tank |
| Place of origin |  Menghe |
| Service history | |
| In service | 1977-present |
| Used by | Menghe |
| Production history | |
| Manufacturer | Inmin-Chŏlgang-Nodongja Vehicle Plant (former) Chikai Inmin Jŏncha Gongjang (former) |
| Produced | 1976-1992 |
| No. built | 32,000 |
| Variants | JCh-4G, JCh-4N, JCh-4D, JCh-4R |
| Specifications | |
| Weight | 39.2 metric tonnes |
| Length | 10.68 m (inc. gun and fuel drums) |
| Width | 3.35 m |
| Height | 2.44 m to turret roof |
| Crew | 4 (driver, gunner, commander, loader) |
| Armor | welded steel plate Turret face: 280mm Glacis plate: 120mm at 70 degrees |
Main armament | 107mm JP-107/56 |
Secondary armament | 12.7mm GCh-75Ch HMG (commander’s cupola) 7.62mm GCh-77Ch machine-gun (co-axial) |
| Engine | 12-cylinder diesel 800 hp |
| Power/weight | 20.9 hp/tonne |
| Suspension | torsion-bar |
| Ground clearance | 45 cm |
Operational range | 500 km |
| Speed | 60 km/h (road) |
The JCh-4 (Menghean designation: 4호 전차 / 四號戰車, Sal-ho Jŏncha, meaning "Type 4 tank" or "No.4 tank") is a type of medium tank designed in the Democratic People's Republic of Menghe during the 1970s. It is based on the JCh-3, but incorporates a number of major changes, including a 107mm smoothbore gun, a longer hull, and thicker armor on the turret and glacis plate. These changes were sufficiently major that the vehicle was designated a new tank altogether, rather than a JCh-3 variant.
Development
Even in the early 1970s, the Menghe People’s Army began to express concern that its JCh-3N tank was growing obsolete. It pressured the FSR for permission to import or domestically manufacture the T-66, which would later become the JCh-5, but until 1975 the FSR's government refused to lift export restrictions on the new tank. Even after that point, the Army leadership remained concerned that the JCh-5 was too expensive and unreliable to serve all units, and instead called for a major upgrade to the JCh-3.
The resulting prototype incorporated a number of features not seen on its Soviet cousins. It had a new gun, turret, and hull, and brought a major increase in capability, though it remained behind the global standard for the time. As a result of these extensive modifications, the new vehicle and its successors were classified as a new tank family altogether, rather than variants of the JCh-3.
Design
The most fundamental difference between the JCh-3 and JCh-4 is the latter's hull, which was "stretched" to accommodate thicker frontal plating, a heavier turret, more ammunition stowage, and a more powerful engine. Altogether, the JCh-4's hull is 36 centimeters longer than that of its predecessor. This resulted in considerably greater spacing between the 3rd, 4th, and 5th roadwheels, the main feature allowing one to tell the tanks apart from a distance. Other distinguishing features include a rounder turret with a more bulged face, a bore evacuator closer to the turret than the muzzle, and spare fuel tanks mounted somewhat lower down than on the JCh-3.
Armament
The JCh-4's main armament is a JP-107/56 107mm smoothbore gun with a heavier thermal sleeve, a change intended to improve armor penetration and barrel life. As a smoothbore weapon, it was also optimized for firing APFSDS ammunition, though APFSDS cartridges with rifled slip rings later became available for the JCh-3. The gun is equipped with both vertical and horizontal stabilizers.
As on the JCh-3, the gun is manually loaded, but the turret layout is reversed, with the gunner and commander on the right and the loader on the left. This change permits the loader to push with his right arm. There is also an automatic mechanism and hatch on the turret rear to eject the end stubs from combustible-case rounds, speeding up the loading process. The lengthened hull allows space for additional ammunition, bringing the total to 44 rounds, despite their larger size.
The commander's gun was also upgraded to a GCh-75, a license-produced copy of the FSR's SBK machine gun. This weapon has a somewhat greater effective range and rate of fire than the preceding HMG, but more importantly, it allows the commander to aim and fire his machine-gun from within the tank - as on the JCh-5 and subsequent Menghean tanks. The co-axial gun is a GCh-77Ch, newly developed at the time, with a high rate of fire.
Protection
In addition to carrying a more powerful main armament, the JCh-4 was also better-protected. Its hull glacis plate is 20 millimeters thicker and set at a steeper angle, while its turret incorporates thicker armor on the frontal arc, and has a less noticeable slope on the roof. Side, rear, and floor armor are identical in thickness to armor at the same locations on the JCh-3. Despite these improvements, the JCh-4 remained a poorly armored tank in all of its variants, and could easily be penetrated by contemporary main battle tanks at regular combat ranges.
From the first "G" variant onward, the JCh-4 also incorporated a CBRN protection system consisting of airtight hatches and air filters, allowing the tank to operate in contaminated areas. The breach was broken by the cartridge-ejection mechanism, however, and overpressure was not sufficient to compensate for this.
Mobility
To compensate for its heavier armor, the JCh-4 was fitted with a more powerful 800-horsepower engine, giving it a power-to-weight ratio of 20.9 hp/tonne. On level roads, it could achieve top speeds of 60 kilometers per hour, at which point it was limited mainly by the vibration of the tracks, which lacked return rollers.
The large engine was considerably thirstier, but the JCh-4 compensated for this by adding additional fuel tanks along the outside of the hull, on top of the track covers. This extended operational range to 500 kilometers, or 650 with external fuel drums attached.
Variants
JCh-4N
Introduced in 1983, the JCh-4N upgraded the tank's electronics and fire-control systems, though they still remained well behind the global norm. Night vision was enabled by an infrared spotlight on the right side of the turret face, combined with a passive infrared sight mounted over the gun. The tank also carried a snorkel behind the turret, allowing water-crossing operations, and ten smoke-grenade launchers, six on the left and four on the right.
JCh-4D
The JCh-4D was a further upgrade introduced in 1986, one year before Menghe's Decembrist Revolution. In addition to the fire-control upgrades of the JCh-4N, it adds ERA bricks to the turret and hull. In Menghean sources, these are referred to as "first-generation ERA," and consist of two angled explosive panels encased in steel within a metal-skinned "brick." The layout is designed to combat high-explosive anti-tank warheads, and is only marginally effective against APFSDS rounds and tandem-charge projectiles.
JCh-4N hulls refitted to JCh-4D standard bear the designation JCh-4D1. Because the electronics are unchanged, the two types are functionally identical.
A subsequent upgrade, JCh-D2, added compatibility with the YDCh-15 gun-launched anti-tank guided missile. It was introduced in 1993. The YDCh-15 brought significant improvements in accuracy, but it was hampered by poor penetration, especially against modern composite armor schemes.
JCh-4R
A minor upgrade applied to existing -4D hulls from 2006 onward, the JCh-4R adds a moderately improved fire-control system, comparable to that on the JCh-5R. By this time, the JCh-4 was already rare in active units, though still common in the mobilization reserves. The goal of this upgrade was to preserve its usefulness for another ten years until the vehicle's retirement.
Other variants
- JCh-4G1: JCh-4G with slat armor around the turret and along the hull sides, an upgrade retrofitted to existing units. First seen in 1984.
- JCh-4DS (Daedae Saryŏngcha): Battalion command tank with a larger VHF radio set for long-distance communication.
- JCh-4JGCh (Janggab Gunan Chalyang): Turretless armored recovery vehicle with a dozer blade, lifting crane, and powered winch.
125mm prototypes
Beginning in the 1970s, the Menghean People's Army expressed interest in upgrading the JCh-4 with a heavier main armament, specifically a 125mm smoothbore gun based on those entering service with the Federation of Socialist Republics. The first prototype, designated Sije-Chalyang 115 (시제 차량 115, Prototype Vehicle 115), was first tested in 1979, just one year after the baseline JCh-4G entered service. It used the same overall design, including the same turret, but added a 125mm smoothbore gun in place of the 107mm weapon, on a slightly reinforced set of trunnions. The gun was manually loaded, a somewhat time-consuming process when handling two-piece ammunition in the cramped confines of the turret.
Another prototype, Sije-Chalyang 117, incorporated a carousel autoloader similar to that which would soon be used on the JCh-5. It also used a new turret with a somewhat lower profile, apparently with provisions to include composite armor layers in subsequent versions. The crew was reduced down to three.
The timing of these prototypes is unusual, as they appeared at a time when development work on the JCh-5 was already nearing completion; the first service deliveries of the latter vehicle were made in 1982. It appears that they were intended as a fallback option in case the JCh-5 proved too unreliable or expensive. As the JCh-5 proved adequate in both these categories, and possessed superior fighting characteristics, the Menghean military appears to have abandoned these prototypes.
The 125mm gun program was unexpectedly revived in 2010, when the Menghean Army floated an interest in developing a major upgrade which could be applied to existing MCh-4s in reserve storage. One of the responses, Sije-Chalyang 324, incorporated an all-new turret with composite armor, ERA panels, and a 125mm gun firing one-piece ammunition from a bustle autoloader based on that used by the JCh-6. The autoloader itself only carried 20 rounds, but more could be carried in the front left hull beside the driver and under the turret floor. The turret and hull could also be fitted with “Second-generation” ERA, moderately effective against kinetic energy threats. According to independent estimates, the Sije-Chalyang 224’s armor configuration is not considered sufficient to protect it from contemporary one-piece 125mm APFSDS fired by the Bison tank, but it can provide protection against the older Bear’s APFSDS ammunition. Also included in the design was another engine upgrade, this time a 900-hp powerpack which could be removed as a single unit for easier maintenance.
As production of the JCh-4 had already stopped, Sije-Chalyang 224 was intended to function as a “drop-in” upgrade; factory crews would only have to take the old tank, remove the turret, replace the ammunition stowage racks and electronics within the hull, replace the engine, and install the new turret into the old turret ring, later adding the ERA panels if necessary. But in spite of the type’s good performance, by the time the first prototypes were tested in 2013, the Menghean Army had decided to retain its JCh-4s in their present state and focus on replacing them with JCh-5s moved down from upgraded active units.
As such, the Sije-Chalyang 224 was never accepted into Menghean service, though since 2013 it has been marketed for export as the JCh 4/6.