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.

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 sideways V-12 diesel generating 680 hp. Minor changes to the hydraulics and autoloader improved their reliability while maintaining the same level of effectiveness. The co-axial machine gun was replaced by a GCh-77 chambered in the 7.5×54mm cartridge, for parts and ammunition commonality with other Menghean tanks. 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 distinctive 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 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. 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--including the stereoscopic rangefinder--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.

JCh-5M

Designed in 2010, the JCh-5M applied successful features of the JCh-6D to the JCh-5 chassis. It was designed as a "bolt-on" upgrade, which could easily be retrofitted to existing units without restarting JCh-5 production. Most of the changes related to the fire-control system: a muzzle reference device was installed atop the barrel, and new visual-wavelength and infrared sights were installed in place of the old ones. This change also enabled the removal of the active IR spotlight on the turret face, and allowed ERA panels to be extended over the area it had covered.

Contrary to initial expectations, JCh-5M did not incorporate "third-generation ERA" of the type used on the JCh-6D. Instead, it relied on the "second-generation" panels used on the JCh-5R, which were lighter, more reliable, and easier to manufacture.

The JCh-5M also incorporated a new storage system on the turret rear. Sometimes mistaken for a bustle autoloader of the type used on the JCh-5/6, this is actually a replacement for external storage bins, and cannot be accessed from inside the vehicle. The central-rear bin is used to hold spare 125mm shells and propellant charges, eliminating the loose ammunition stowage within the crew compartment which had contributed to catastrophic detonations on penetrated vehicles during the Ummayan Civil War. Live-fire tests against JCh-5N and JCh-5M hulls at full ammunition loads have confirmed that the latter are considerably less prone to catastrophic detonations, but can still cook off if the carousel autoloader itself is hit.

A final interesting feature of the JCh-5M is its MChGJ-0800 short-range radio antenna, also adopted after successful tests on the JCh-6D. This uses a frequency in the C band, between 4 and 8 GHz. The frequency is not high enough to suffer severe problems with atmospheric attenuation in rain, but is still limited to line-of-sight communication, as its waves do not experience surface diffraction. This makes it a highly secure band, unable to be intercepted by enemy units outside line-of-sight and nearly impervious to jamming. As on the JCh-6D, this system would be used for close-range communication between tanks in a Company under conditions of intense electronic warfare, effectively a replacement for semaphore flags carried by the tank commander.

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.

Ammunition

Like the T-66, the JCh-5 uses a carousel autoloader in which ammunition is broken into two pieces. For high-explosive and HEAT rounds, the projectile is stored horizontally on the floor facing inward and the propellant charge is stored vertically behind it, and both are swung into the breech in a single motion. For APFSDS rounds, the projectile, sabot, and additional propellant are stored in the forward section of the round on the floor. Gun-launched ATGMs are also broken into pieces to allow storage. The layout, adopted in Letnia, allows for a more compact vehicle, but also raises the risk of catastrophic detonation if a projectile penetrates through the side of the tank and strikes the upright propellant charges.

When first introduced to service, the JCh-5 used the Type 75 APFSDS round, a licensed copy of the Letnian 3BM-17 projectile. This was a simple, all-steel export grade round, with about 300mm RHAe penetration. The Type 84, its successor, was a copy of the Letnian 3BM-22 projectile, though it had a slightly different sabot design. It had a larger penetrator cap, but still relied on a steel body, and if comparable in performance to the 3BM-22 would have achieved about 400mm RHAe penetration at 2000km range. Both projectiles sat entirely within the forward section of the round.

Following the Decembrist Revolution, Menghe began work on new ammunition types with greater penetrating capability. The Type 93, apparently derived from the 3BM-32 projectile, uses a longer depleted uranium projectile and reportedly achieves 500mm penetration. The Type 98, an independent Menghean design bearing some resemblance to the longer 3BM-42M, reportedly achieves 580mm. Further growth was limited by the dimensions of the autoloader: the projectile section stored on the autoloader floor can be no longer than 640 mm. This constraint drove work on the JCh-6, which could carry unitary ammunition in a new bustle autoloader. Some sources report that in 2009 the Menghean Army introduced a Type 09 two-piece APFSDS round for the JCh-5 with "improved performance against reactive armor;" though details are scarce, some analysts believe that the Type 09 uses the same steel head and uranium body as the full-length Type 08 special.