OBT-1
| OBT-1 | |
|---|---|
 Most variants of the OBT-1 with the year they entered service. | |
| Type | Main Battle Tank |
| Place of origin |  Reberiya |
| Service history | |
| In service | 1971-present |
| Used by | Reberiya |
| Production history | |
| Designer | ИОиМ (Institute of Defence and Mechanization) |
| Designed | 1965-1969 |
| Manufacturer | Synyosercheva Faktora Bronevyh Traktoriv |
| Produced | 1971-1988 |
| No. built | 1,392 |
| Specifications | |
| Weight | 52,4 metric tonnes |
| Length | 10,2 m (with gun forward). |
| Width | 3,55 m |
| Height | 2,68 m (commander cupola) / 3,15 m (AAMG). |
| Crew | 3 (commander, gunner, driver). |
| Armor | Composite armor (undisclosed). |
Main armament | 115/51mm rifled gun (40 rds) |
Secondary armament | 15,5x106 mm FN BRG (1,000 rds) HMG (commander’s cupola) 6,3x48 mm FN MAG coaxial MG (2,400 rds) (co-axial). |
| Engine | 12-cylinder two-stroke diesel engine. 850 hp |
| Power/weight | 16.2 hp/tonne |
| Transmission | Eight-speed (5+3) electro-hydraulic. |
| Suspension | torsion bar |
| Ground clearance | 38 cm |
Operational range | 350 km |
| Speed | 50km/h (road) 38km/h (offroad) |
Development
The OBT-1 is a main battle tank developed by ИОиМ (Institute of Defence and Mechanization) and produced by CФБТ (Synyosercheva Faktora Bronevyh Traktoriv) to replace its aging park of tanks, namely ShBT-6 and MBT-4. Development started in 1965, with first three prototypes with different conceptual schemes undergoing their trials in 1968. Of those three, prototype no.2 was chosen for its superior protection utilizing all-new composite armor, a powerful two-stroke diesel engine and then-revolutionary complicated autoloading system, which provided the tank with an 7-8s automated reload cycle. Production of the tank started in 1970, with the first public display of the tank being at the Portomyr Arms Expo in 1972. The tank was deemed a success for the relatively small nation, however the premiere was dwarfed by the new T-74 tank being showcased there as well.
Modernisations
By 1977, vehicles underwent their first major upgrade, resulting in the appearance of OBT-1P, which fixed a most of issues that appeared during the initial service, as well as added a remote weapon control system for the AA machinegun, a new fire control system, it's first armor upgrade and an improved 950 hp (1280 kW) engine to remedy the issue of the mediocre mobility of the tank. OBT-1P's were first seen en masse in the middle of the Tyranese-Sieuxxeran crisis in 1978, rumored to be preparing for offensive action if need be.
After another decade of being in service, the emergence of new MBT generation, lack of defence spending and relative peace in the region resulted in further modernisation of the platform rather than a development of a new tank. That resulted in the OBT-1P2 upgrade featuring an all-new turret utilizing modern armor packages, further FCS upgrades and hull applique armor. Modernization was made to all Reberiyan OBT-1's throughout 1989-1996. Nowadays the tank is slowly being replaced by the relatively new OBT-2 tank, with most of the tanks being sent to the second-rate units, sold off or stockpiled.