JCh-5

JCh-5
All five service variants of the JCh-5.
Type	main battle tank
Place of origin	Menghe
Service history
In service	1979-present
Used by	Menghean Army
Wars	Ummayan Civil War Innominadan Crisis
Production history
Designed	1975-1979
Manufacturer	Inmin-Chŏlgang-Nodongja Vehicle Plant
Produced	1979-2008
No. built	at least 24,000
Variants	JCh-5G, JCh-5N, JCh-5D, JCh-5R, JCh-5M, JCh-5/6
Specifications (JCh-5D)
Weight	45.5 metric tonnes
Length	9.64 m (inc. gun and fuel tanks) 6.41 m hull only
Width	3.64 m
Height	2.07 m to turret roof
Crew	3 (driver, gunner, commander)
Armor	welded steel plate "Second-generation ERA" (Menghean classification)
Main armament	125mm L/45 smoothbore gun
Secondary armament	12.7mm HMG (commander) 7.62mm GPMG (co-axial)
Engine	KP-12 diesel 708 kW (950 hp)
Power/weight	21.1 hp/tonne
Suspension	torsion-bar
Ground clearance	38 cm
Operational range	600 km (internal fuel), 800km (with external tanks)
Speed	60 km/h (road)

The JCh-5 (formal designation: 5호 주력 전차 / 五號主力戰車, O-ho juryŏk jŏncha, "No.5 Main Battle Tank;" short designation 전차-5, Jŏncha-o) is a main battle tank introduced in the Democratic People's Republic of Menghe and inherited by the Socialist Republic of Menghe. Though based on the Kolodorian T-64, it was specially modified to satisfy Menghean reliability requirements, and later followed its own upgrade and development trajectory. With a three-man crew, a low profile, and a 125mm autoloading gun, it introduced many features that would be emulated by later Menghean main battle tanks such as the JCh-6 and JCh-8.

A total of 8,200 JCh-5 tanks of all variants were produced in Menghe between 1979 and 2007, making the JCh-5 second most widely-produced tank in Menghe after the JCh-4. Along with the JCh-4, it is still widely used by Menghean reservist units, though in active units it has been fully replaced by the JCh-6 and JCh-8. Most JCh-5s in Menghe have been upgraded with improved fire-control systems, reactive armour, and the ability to fire gun-launched anti-tank guided missiles.

Development

T-64 evaluation

After the outbreak of the Vinyan War in April 1975, the Democratic People's Republic of Menghe sent observers to its communist ally Kolodoria to study the fighting, and closely followed reports from the front lines. Early clashes in the first year appeared to verify Menghean commanders' concerns that the JCh-2 was an obsolete tank and the JCh-4 was an insufficiently radical improvement. Menghean observers were particularly impressed by the performance of Kolodorian units with T-64s, and inquired about the possibility of importing the latest model. Unwilling to divert production away from the front lines, where new tanks were urgently needed, the Kolodorian government shipped four T-64Bs to Menghe for evaluation and held out the possibility of a production license if the war did not promptly conclude.

Menghean crews tested and evaluated the tanks in late 1975, and identified a number of problems not present in the battlefield reports. In particular, they found the T-64's engine to be unreliable, a problem intensified by Menghean engineers who were unfamiliar with the opposed-piston design. This also resulted in concern about high production costs, particularly with Menghe facing production bottlenecks in optical equipment and electronics.

The Menghean Ministry of National Defense also recommended updating the tank based on combat reports from the Vinyan War. For example, the T-64's ZU-64 cupola allowed the commander to remotely control the machine gun from inside the vehicle, a feature that initially impressed Menghean designers. Actual combat experience in the Vinyan War, however, indicated that a closed mount was disadvantageous. From below armor, the commander has limited visibility at high angles, and a low chance of seeing incoming helicopters or attack aircraft. The below-armor anti-aircraft sight's narrow field of view also makes it difficult to properly lead a fast-moving target. In actual combat, tank commanders on both sides often entered battle standing or peering above the hatch to look for ATGM teams, which were also harder to spot through the periscopes. Aiming to the rear, while permitted by the 360-degree cupola ring, was impossible in practice because the commander could only sit facing forward in the cramped turret. Finally, both threats which the commander's HMG is meant to counter--namely, helicopters and ATGM teams--threaten the tank with an anti-tank guided missile, which poses the same threat to the commander whether his hatch is open or closed, and are beyond the range of small-arms fire.

JCh-5G

With Kolodorian approval, the DPRM began development on a customized variant better suited for Menghe's strategic needs. They lengthened the hull by half a meter and installed a V-12 diesel generating 660 hp. The engine was placed with the crankshaft running perpendicular to the vehicle's path of travel. Though less powerful than the T-64's 5TDF opposed-piston engine, the Menghean powerplant was easier to manufacture, more reliable, and more familiar to Menghean mechanics and engineers.

The design of the commander's cupola was also heavily revised, resulting in a layout similar to that of the Letnian T-74. The GCh-75 HMG is fixed to a separate race ring that runs around the outside of the cupola on a separate track. Normally, it is locked in position facing the rear. This allows the commander to independently rotate the cupola without having to also rotate the heavy and off-center machine gun. To use the machine gun, the commander opens the hatch, stands on his seat, faces the rear, and holds the HMG's manual controls. A toggle lever allows the commander to either traverse the HMG independently on its race ring while leaving the cupola fixed in place, or lock the two race rings together and traverse the HMG and cupola as a single unit. The former is better for small adjustments, and the latter for pivoting to the direction of a threat.

Due to export limitations, and due to Menghean MoND hesitancy about introducing complex weapon systems, the capability to fire anti-tank guided missiles from the gun was omitted. Accordingly, the laser guidance block on the right side of the T-64B turret was omitted as well. The T-64B's infrared laser rangefinder, however, is retained, replacing the optical stereoscopic rangefinder in the T-64A and the JCh-4. This gives the JCh-5 considerably better accuracy than other Menghean tanks in service at the time of its introduction.

A number of smaller changes were incorporated as well. The co-axial PKT machine gun was replaced by a GCh-77 chambered in the 7.5×54mm cartridge, for parts and ammunition commonality with other Menghean tanks. The dials, optics, controls, and other labels were replaced with Menghean-language versions. In all other respects, the resulting design was identical to the T-64B, retaining the base design's left-side infrared spotlight, its composite armor scheme, and its small roadwheels.

A prototype built to these specifications underwent mobility and shooting trials in 1978, and quickly met state approval from the Ministry of National Defense, which was impressed with their characteristics and under pressure to bring a modern MBT into service. It received the designation JCh-5G. Production began in 1979 at the Chikai Heavy Machine Building Plant in Jinjŏng.

JCh-5N

An improved variant, the JCh-5N, entered service early in 1985. It can be easily distinguished from the JCh-5G because of its more angular welded turret, which incorporates an entirely new composite armor scheme. The new scheme uses layered ceramic and steel plates, and is reportedly both more effective and easier to manufacture. It is also easier to maintain: the welded panels above the composite armor sections can be cut off at a forward depot or factory, allowing workers to remove the damaged composite plates and install new ones. Internally, the welded turret is slightly larger, allowing the installation of more radio equipment.

The JCh-5N also adds compatibility with the YDCh-13 gun-launched anti-tank guided missile. The laser guidance unit is located on the right side of the turret, forward of the commander's HMG mount. This guidance unit must be removed in order to access the cover panels for the composite armor. The Ministry of National Defense had planned to improve the optics as well, but Ryŏ Ho-jun's decentralization of factory networks had caused problems along the supply chain, so the old optics were retained.

Despite the economic disruption, Menghe was able to open a second production line for the JCh-5N in 1984, the same year the new variant entered production at the Chikai plant. This new facility, the Insŏng Machine Building Plant, was located in southern Menghe, far from Dayashina, which posed the main threat to Menghe at the time.

JCh-5D

Introduced in 1991, the JCh-5D addresses many faults which Chikai's engineers identified in the early 1980s but were unable to fix. It features improved optics and fire-control, including a laser rangefinder, and an improved gun stabilization system. It still relies on active infrared illumination for night vision, but the IR receiver is more sensitive and can see illuminated targets out to 800 meters. Many of these components were imported initially, though over the 1990s Menghe steadily increased the share of domestic components.

Externally, the JCh-5D sported a full suite of explosive reactive armour. Menghean sources refer to the reactive armor used on the JCh-5D as "first-generation" ERA: produced in small brick-like blocks, it is effective against single-charge HEAT warheads, but not tandem HEAT warheads or kinetic energy penetrators.

A more powerful diesel engine with an output of 950 horsepower more than offset the added weight of the reactive armor, increasing the JCh-5's road speed and improving its offroad mobility. The new engine was also more reliable, partly due to greater access to imported parts and higher-quality machining equipment.

Although JCh-4 production stopped in the early 1990s, a victim of the military budget cuts early in Choe Sŭng-min's tenure, JCh-5 production at both tank factories continued, albeit at about half of its peak level. Despite pressuring the Army to accept force reductions as part of a plan to improve relations with Dayashina, Choe Sŭng-min personally advocated for continued production of the JCh-5, on the basis that it would maintain employment at both factories and preserve Menghean AFV design expertise. Choe had also commanded a division with JCh-5s during his military career, even leading them into Donggyŏng during the Decembrist Revolution, and had a favorable impression of the vehicle.

JCh-5R

Though it came last in the series, the JCh-5R was in many respects the most improved new-production variant of the JCh-5. It added an entirely passive night vision system based on infrared imaging, increasing the range of detection of enemy targets and eliminating the need for an active infrared spotlight which could give away the tank's location. The gunner and commander both received new dual-mode electro-optical units with variable magnification. Along with further improvements to the stabilizer and laser rangefinder and the addition of a 360-degree wind and temperature sensor, this brought the JCh-5R's accuracy up to modern levels.

Externally, the main change to the JCh-5R was the installation of what Menghean sources term "second-generation" ERA. This reactive armor uses larger plates set at a steeper angle, and is able to wear down, destabilize, and shatter kinetic energy penetrators, improving the JCh-5R's protection in tank-on-tank combat. Internally, the turret floor and its plating were altered to allow the loading of 125mm APFSDS ammunition with a longer kinetic energy penetrator, though not as long as the KEP used on the JCh-6 and its successors.

Overall description

The JCh-5 shares the internal layout of the T-64 before it, with the driver sitting in the front and center, the commander sitting on the right side of the turret, and the gunner sitting on the left side of the turret. The interior of the tank is cramped, but the smaller crew compensates for this somewhat. The 125mm main gun is fed from a carousel autoloader that sits under and around the turret crew, with the charges stored upright forming the walls of the turret basket. The autoloader holds 28 rounds and can reload the main gun at 8 rounds per minute, slower than a fresh human loader in a steady tank but faster than a tired loader or a loader in a moving tank. Up to 8 additional rounds, for a total of 36, can be stored around the interior of the hull, but this increases the already-high risk of explosion if the armor is penetrated.

A disadvantage of the carousel autoloader design is that the length of the projectile is limited because the entire round must be broken down into two pieces for storage. This was not a problem for early ammunition types, but it prevented the adoption of APFSDS penetrators beyond a certain length, limiting future growth in armor penetration capability. Subsequent Menghean main battle tanks, such as the JCh-6, addressed this by placing longer unitary ammunition in the turret bustle.

Full list of variants

Main battle tanks

• JCh-5G - Initial production model, manufactured between 1979 and 1983 exclusively at the Chikai Heavy Machine Building Plant. Of all JCh-5 variants, it most closely resembled the T-64B, though it lacked the latter's ATGM guidance capability and had a different machine gun cupola. It is the only JCh-6 variant with a cast turret.
  • JCh-5G1 - Refitted with smoke grenade launchers on the turret face.
  • JCh-5G2 - Refitted with "first-generation" ERA. It closely resembles the JCh-6D, especially with its turret masked by reactive armor. The most visible difference is that it has one fewer row of ERA bricks on either side of the turret face.
• JCh-5N - New production model introduced in 1984 at the Insŏng Machine Building Plant. It has a welded octagonal turret with a new composite armor scheme, though the two turrets are similar in approximate shape and layout. The JCh-6N also introduced the ability to fire the YDCh-13 GLATGM.
  • JCh-5N1 - Designation for JCh-5Ns fitted with the ERA blocks of the JCh-5D. The fire-control system was not upgraded.
  • JCh-5N2 - Designation for JCh-5Ns upgraded to JCh-5R standard. They are essentially identical to JCh-5D1s.
• JCh-5D - Production model introduced in 1991. It incorporates minor optics and stabilizer improvements compared to the JCh-6N, but retains the obsolete active infrared illumination system. It is also the first JCh-5 variant to carry reactive armor, with small blocks on the turret, hull sides, and glacis plate.
  • JCh-5D1 - Designation for JCh-5Ds modified to JCh-5R standard. The first-generation ERA blocks are replaced by second-generation ERA blocks, which can degrade the performance of APFSDS ammunition. The commander's front periscope was replaced with an electro-optical sight with visual and passive infrared modes, though the two-part cupola design was retained, and the commander cannot operate the 12.7mm heavy machine gun remotely. Upgrading the gunner's sight presented similar problems, as the JCh-5R's combined visual, infrared, and laser sight required a new turret roof design with a wider gap through the roof. Rather than thoroughly cutting and welding the existing turret roof armor, the designers installed a separate IR and laser guidance sight in place of the existing auxiliary gunner sight, and replaced the visual sight as well. The gunner thus has two different gunsights to choose from. Refitted JCh-5D1s first appeared in 2008.
• JCh-5R - New variant produced from 2002 to 2007. Features an entirely new gunner's sight and cupola, though the rest of the turret is identical to the base turret of the N and D variants. It also features "second-generation" explosive reactive armour with greater effectiveness against APFSDS ammunition.

JCh-5/6

An interesting evolution of the JCh-5 series was the cancelled program later designated JCh-5/6. It began in 1996, not long after the Menghean government issued a design requirement for a new main battle tank capable of firing more effective single-piece 125mm APFSDS ammunition. The main design team responded with Project 805, which would become the JCh-6. A secondary design team, however, produced an alternative design, which was intended to take the place of Project 805 if it fell short of expectations.

Project 804

This alternative program, designated Project 804, was intended to meet the design requirements while continuing to use the same base chassis as the JCh-5 series. The turret face, as well as the glacis plate and hull sides, carried the same "second-generation ERA" used by the contemporary JCh-5R. On the rear of this turret was a prominent bustle with a cycling-belt autoloader carrying 18 main gun rounds. The bustle itself was thinly armored, with protection only against shrapnel and ammunition of less than 12.7mm caliber, but in the event of a more serious penetration its upper panel would blow off to relieve the pressure. Additional main gun ammunition was stored on the turret floor in place of the carousel autoloader, which was removed, and loose ammunition was no longer stored in the hull itself. In the hull rear, a more powerful engine allowed for a higher power-to-weight ratio, increasing road speed and offroad handling.

Three prototypes were built for testing in 1998, and they performed adequately in demonstration trials, meeting nearly all of the government's design requirements except below-ERA armor protection on the hull. They were surpassed, however, by the Project 805 competitor, which exceeded its targets in all areas. Project 805 was then accepted for service as the JCh-6, while Project 804 was shelved and its prototypes moved into storage.

Project 814

Interest in the notion of a bustle-armed JCh-5 returned in 2010, after High Command decided to prioritize new-build production of the JCh-6 over the JCh-5 variant. The Marine Infantry force in particular expressed its interest in such a vehicle, which would be lighter than the JCh-6 and therefore more suitable to amphibious transport. At High Command’s approval, the original team was reassembled under an arms subsidiary of Samsan Heavy Industries and instructed to revisit the concept in line with the Marine Infantry’s requirements.

Although the Project 804 prototypes provided some initial conceptual guidance for the new design, the resulting Project 814 proposal amounted to a new design. The design team built an all-new hexagonal turret with lighter but more efficient composite armor of the type used on the JCh-6R, with a lightly armored bustle similar to that of Project 804 protruding from the rear. In addition to allowing for the storage of longer APFSDS ammunition carried by the JCh-6, the autoloader could also handle the YDCh-73, which was introduced to limited service in late 2016. To compensate for the thinner base armor, the designers added a standoff hard-kill active protection system, the first of its kind carried by a Menghean main battle tank. The engine was also improved yet again, to a 12-cylinder diesel with an output of 1020 hp but the same overall dimensions to allow refitting into the same engine compartment, to maintain the same power-to-weight ratio as the JCh-5R despite the added weight. After several years of testing, the vehicle was approved for service in 2013, with the Marine Infantry placing an order for 250 vehicles.

Owing to its conceptual resemblance to the JCh-6, and to clarify confusion over compatibility with full-length APFSDS ammunition, the new tank was designated the JCh-5/6 in service. The same designation is sometimes retroactively applied to the Project 804 prototype, resulting in some confusion over the origin of the term. Although marketed as an all-service vehicle, in Menghean service it is only used by the Tank Battalions of the Marine Infantry.