JCh-5.5

JCh-5.5 is the final designation given to an interim main battle tank consisting of a JCh-5 hull with an all-new welded turret and bustle autoloader. It is a hybrid design combining features of the JCh-5 and JCh-6, hence its unconventional 5.5 designation. It was also known under the prototype designations S.804 and S.814. All JCh-5.5 tanks are factory rebuilds of existing JCh-5 vehicles, with the old turret removed, the hull internals refurbished, and the new turret installed in place.

Development

S.804

S.804, or Sije Charyang 804 (prototype vehicle 804), was the first design in the evolution of the JCh-5.5. It was developed in the 1990s, initially as a low-priority side project by the Chikai Tank Design Bureau. In 1996 engineers at Chikai pulled a JCh-5D from the assembly line and completed it with the changes spelled out in prior design work, resulting in the first and only operational S.804 prototype. This prototype was never fitted with ERA tiles, as it was only built to prove the viability of the underlying concept, but it would have been fitted with ERA if accepted for service.

The S.804 design was very similar to the JCh-5, owing to its improvised construction, but did incorporate one important difference: a 14-round bustle autoloader installed in a box on the rear of the turret. This allowed the tank to carry full-length unitary 125mm ammunition, which in turn would allow the development of longer APFSDS penetrators. The carousel autoloader was retained, but it would only be loaded with HE, HEAT, and ATGM ammunition. The autoloader was thinly armored, protected against shrapnel and 12.7mm HMG fire but not autocannon or tank fire, but it featured blowoff panels on its roof and the turret rear armor served as a form of protective bulkhead for the crew.

The Menghean Army showed some interest in the new vehicle, but the Ministry of National Defense did not ultimately accept it for service. In particular, MoND evaluators appointed by the Army were concerned about the thin armor around the turret bustle and mechanical problems in loading tests. Some Army staff also advocated for developing an entirely new main battle tank, which would allow them to address many other issues with the JCh-5. This new main battle tank became the JCh-6, which drew heavily on the S.804's basic configuration but was ultimately an entirely different vehicle. With the JCh-6 program receiving MoND approval, the S.804 project was shelved, only to see new life over a decade later as the S.815.