JCh-8

The JCh-8 (formal designation: 8호 주력 전차 / 八號主力戰車, Pal-ho Juryŏk Jŏncha, "No.8 Main Battle Tank;" short designation: 전차-8, Jŏncha-pal) is a fourth-generation main battle tank developed in Menghe. Publicity announcements have also used the nicknames Jŏnsa, or "Warrior", and Usan, after the Battle of Usan Pass during the Five States and Seven Fiefdoms period.

Equipped with a hydropneumatic suspension, an active protection system, and provision for a 140mm main gun, the JCh-8 is considered one of the most advanced MBTs in Septentrion. It entered service with the Menghean Army in 2018, where it currently supplements the JCh-6 in high-readiness units. As of early 2019, less than 100 are in service, and there has been no discussion of authorizing it for export beyond Menghe.

Development

In 2006, concerned over the new military standoff with Maverica and Innominada, the Menghean Ministry of Defense issued a request for a new main battle tank. At this point, the JCh-6 had only been in service for two years, and there were no plans to end production; but combat experience during the Ummayan Civil War had revealed that the JCh-6's armor was insufficient to meet parity threats, and the Army was concerned that the already cramped vehicle left little room for major upgrades in the future.

Under the terms of the design competition, the new tank would need a flat-faced turret with thicker composite armor, a hydropneumatic suspension to improve stability on rough terrain, and a turret capable of mounting a 140mm gun in future upgrades. They also requested a high power-to-weight ratio, which led the designers to favor a gas turbine engine. At the time of its development, the new tank would be a world-class design, on par with the latest main battle tanks serving with the Grand Alliance. As the Menghean designers soon learned, however, greater advances would also demand more expenses and a longer development time.

The Chikai Heavy Machine Building Plant, producer of the JCh-5 and JCh-6, took responsibility for the design process. Development was conducted under a veil of near-total secrecy, with few individuals outside the design team and the Army's high command aware of the project's status. By the early 2010s, there were domestic and foreign rumors of a new Menghean MBT in development, but no photos had been released; when the Ministry of Defense published photos of the JCh-6R in May 2014, some foreign intelligence agencies erroneously identified it as the JCh-8.

The first JCh-8 prototype did begin routine tests in the spring of 2014, but the first confirmed photos of the tank only became available in November of that year. Rumors that the new tank had been sent to the Menghean invasion of Innominada for front-line evaluation later proved to be false. Instead, the two existing hulls remained at a proving ground in Sŏsamak Province, undergoing continued tests.

Originally, the Army planned to adopt the JCh-8 for operational service in 2015, but experience gained from the field tests revealed major shortcomings with the design. Most notably, the gas turbine engine fell short of its original design requirements. While the Chikai design team projected that they could keep fuel efficiency at an acceptable level, the engine greatly surpassed equivalent-size diesel units in fuel consumption even when running at full power, and worse still, it struggled to reach the required level of output. Exact details are scarce, but it appears that the turbine had particularly severe problems with dust at the Sŏsamak testing site.

Distraught at the continuing delays and accumulating costs associated with the project, in late 2015 Menghean Army High Command contracted the semi-private Samsan Heavy Industries Group to design a high-output diesel engine for the new tank. Samsan accepted the offer, and after some negotiation the Chikai Heavy Machine Building Plant relented and ceded control of the powerplant portion of the program. Samsan's Machine Building Division had already gained valuable experience with high-power diesel engines in its civilian projects and in past contracts for the JCh-6R variant, and they were able to produce a diesel powerplant which fit within the space constraints of the JCh-8 rear hull and only fell slightly short of the original power requirement.

At around the same time, new technological developments like the Jŏgran-un active protection suite and the availability of new optics led the Army to expand the list of required features. The combination of new additions and persistent delays caused per-unit costs to steadily balloon. Ultimately, the Army justified the cost on the basis that the extra expense (estimated to be about $200,000 for a full suite) was well below the cost of losing a tank to top-attack munitions, and the design was accepted for service in late 2017. Domestically, top Army officials have expressed serious reservations about whether the JCh-8 could ever be produced on the same scale as the JCh-6.

After a steady stream of publicity photos and demonstration footage scattered through the preceding months, Menghe formally unveiled the JCh-8G service variant at the May 25th National Day Parade in Donggyŏng. Ten tanks equipped with the full defensive suite took part, leading the armored vehicles section of the parade under the banner of the 12th Tank Division. This provided the world with the first high-resolution footage of the JCh-8, and the first of any footage showing the addition of reactive armor and the Jŏgran-un system.

Design

Mobility

Power comes from a 1,200-kilowatt (1,609 hp) 12-cylinder diesel engine mounted lengthwise in the rear of the hull. Gas turbines were considered early in development, but were not implemented on the production version due to delays in development; they may, however, return in future variants. The engine and transmission form a single power pack which can be removed by a crane for easy maintenance and replacement in the field. Like the JCh-6R, it has a top speed of 70 km/h (43.5 mph) on a level paved surface.

The JCh-8 is the first Menghean main battle tank to make use of a hydropneumatic suspension system in place of the more conventional torsion bars. All seven road wheels have self-contained hydraulic arms connecting them to the lower sides of the hull. The driver can adjust the strength of the hydraulic dampening, optimizing mobility on different types of terrain. The adjustable suspension also allows the tank to tilt its hull forward and backward at the driver's command, "kneeling" to improve gun depression and "sitting" to improve gun elevation. It can even lean side-to-side, or remain at a perfect vertical orientation on slightly sloped terrain.

The hydropneumatic suspension arms also eliminate the need for torsion bars running across the bottom of the tank's hull. This allows for internal components like the turret basket to be seated deeper in the hull, allowing for a lower hull profile than would otherwise be possible. Overall, the JCh-8 is slightly taller than the JCh-6R which preceded it, but it is lower to the ground than it would have been with a torsion bar suspension.

See also

• JCh-6
• JCh-7
• BSCh-9