Object 490A "Бунтарь" - "Rebel"

 Work on the new Kharkiv tank has been officially carried out since the early 1980s under the leadership of N.A. Shomin, chief designer of the KMDB (Kharkiv Morozov Machine-Building Design Burau). Initiative work on the new medium tank of the 1980s, NST-80 (New Soviet Tank-80), began even earlier, on 08/17/1977 when a group of designers was formed, approved by N. A. Shomin.

Object 490A "Бунтарь" - "Rebel" running mockup

The layout of the promising tank was represented by two projects - the double Object 490, developed by E.A. Morozov since the end of the 70s, and the Object 490A with a crew of three people, a low-profile turret and outboard weapons, the development of which was supported by DB (Design Burau), weapons systems department, deputy chief designer of the KMDB Kovalyukh Vadim Romanovich.

The layout of Object 490 by E. A. Morozova had a risky and requiring further elaboration solution associated with a crew of two, which increased the requirements for information support and control facilities, while the decisions on the automatic loader were laconic and did not cause problematic issues. In the "Object 490A" tank, despite the relative simplicity of the layout, the stake was placed on promising solutions for ammunition that had not yet been worked out and required time for fine-tuning, associated with variable-form charges (VFC - ЗИФ 'зарядами изменяемой формы').

 

Vehicle layout

01/29/1983 - “I was with Kovalyukh on a wooden mock-up of a vehicle with an externally mounted cannon, the gunner and commander were sitting side by side. I sat inside and felt that the layout option would most likely work out. For some reason, Bershov and Kovalyukh thought that I would solve all the issues related to the placement of the equipment. On the model, I saw that I was mistaken in the control panels. They have to be done differently! A single panel is needed, and many controls can be shared between both operators to allow operators to sit side by side.”

04/11/1983 - “Almost all of the documentation for the product layout has been issued. We made a wooden model, found many flaws, there is practically nowhere to place our equipment. I spoke with Kovalyukh, he began to prove that everything will be provided, but, in my opinion, it is necessary to look at more layout options.”

Object 490A "Бунтарь" - "Rebel" general layout

The tank had a low-profile turret with outboard armament, the driver was located on the left (along the course of the tank), to the right of it there was an internal fuel supply of 1290 litres. The gunner and commander were located on the left in the turret one after another. The commander is behind the gunner to the left of the cannon. Crewing and leaving the tank was ensured through a hatch in the turret.

By 1982, a life-size wooden mock-up of the Object 490A was made. Later, two prototypes were made.

The armament consisted of a 125 mm high power cannon, which was the 2A66M. The mechanized stowage occupied the right side of the fighting compartment. The rounds were placed horizontally in 5 rows. The crew was separated from the elements of the loading mechanism by a partition. Regarding the 2A66 and its more exact variant being the 2A66M. The gun should not be confused with the standard 2A66 which has been present on tanks from the UVZ Design Burau and KMDB. Those primarily being Object 185, Object 186, Object 187 (some prototype variants), and the Object 490 "Тополь" - "Poplar" which used the 2A66. The main difference between the 2A66 and 2A66M is the lack of a muzzle brake and ejector on the 2A66M variant.

As a prospect, it was supposed to apply new solutions for the ammunition of the tank - rounds with a variable-form charge (VFC - ЗИФ 'зарядами изменяемой формы' ). Such rounds made it possible to create an automatic loader with the maximum possible density of use of the internal volume of the tank.

In 1984, a new version of the Object 490A tank layout was developed, in which the crew was housed according to the classical scheme. The gunner is on the left and the commander is on the right in the low-profile turret. The automatic loader was changed, the ammunition was placed in two mechanized stowages in the front and rear sectors of the turret. Rounds in trays with a locking system were placed horizontally. In the centre of the aft part of the fighting compartment, there was a mechanism for lifting rounds, which entered the removed weapon installation through a hatch in the roof of the fighting compartment. From the packs, the rounds entered the ring conveyor located under the crew platform. The tank had 40 rounds of ammunition.

Object 490A "Rebel" model. On the left, a gunners night sight using a fibre-optic device for transmitting data. On the right is the gunners daytime sight and the commander's panoramic sight.

Firepower

 

The "Object 490A" tank uses the principle of constructing an FCS based on optically coupled blocks using fibre-optic devices. The gunner's sighting system was supposed to be made in the form of a television thermal imaging module located on the right (along the course of the tank) and a day sight with a visual channel directly at the gunner's place.

It was assumed that the sighting module will contain a thermal sight unit, a laser rangefinder unit, a guided projectile guidance channel, which can be coupled with an automatic target acquisition and tracking unit. This gave the following advantages: simplification of the optical-kinematic scheme, reduction of entrance windows and instrument sizes, duplication of fire from the workplaces of the tank commander and gunner, increased accuracy of communication between sights and weapons, improved crew compartment layout, and maintainability.

Fibre-optic devices were originally also used to provide a static view of the tank's crew, the advantage of such devices, thanks to the flexible fibre-optic cables, could provide a static all-round view for the commander without the zones overlapped by the remote weapon installation. But at that time it was not possible to realize the potential of fibre-optic systems - the test results showed that in conditions of daytime observation, the models of the devices have a low-resolution limit and, as a consequence, a small target identification range. When designing a new layout variant "Object 490A" in 1984 and in further developments, classical prism instruments were used. 

Object 490A "Бунтарь" - "Rebel" crew layout

A 125 mm gun of increased power was installed on the running model of the "Rebel", the placement of weapons made it possible to provide a sufficiently high, by Soviet standards, gun depression angle - 8 °. As a prospect for tank armament at that time, a caseless loading gun with variable-shape charges was considered. Since 1980, department No. 31 of the Central Research Institute "Burevestnik" has been involved in development.

There was another prototype that was being worked on in a similar time frame. The Object 477 "Boxer" and its derivative into the "Molot". Which featured a 152mm gun.

So, within the framework of the themes "Commonwealth", "Rebel" and "Taran", samples of a 125-mm caseless tank cannon with an elegant solution of a bolt assembly and a 152-mm large cannon LP-81 and LP-83 were collected.

The Object 490A "Boxer" was another prototype that was also developed by KMDB. But that variant deserves a whole other topic due to some of its differences compared to the Object 490A "Rebel"

Overall, the Object 490A "Rebel" was a very complicated design with some very interesting design choices. Like using Fibre-Optics for data transmission for both gunner and commander. Sadly as with many Soviet late Cold War programs, there wasn't much time and the competition was growing since the Soviet Union needed a new MBT that wasn't related to the already existing arsenal which was made up out of T-64B and T-72B tanks. 

Taken from: book of JSC "Central Research Institute "Petrel" titled " 40 years on guard of the Fatherland and the world. 1970-2010", BTVT,