Staff Writer (Updated: 4/1/2016):
With the fall of the Soviet Empire in 1991, the Russian military fell into a period of low morale and curtailed spending. As such, many projects were either shelved indefinitely or canceled altogether. During the height of the Cold War, the Soviet Army enjoyed the prospect of fielding two Main Battle Tanks (MBTs) side-by-side, beginning with the introduction of the T-64 in 1963. This was then later complemented by the T-72 of 1971. Both tank designs showcased an autoloader feeding a large-caliber 125mm smoothbore main gun. The T-64 was designed as the technology-laden (and therefore more expensive) primary Soviet Army tank solution while the T-72 was intended as the cheaper, production-/export-friendly mark. In the end, however, it was the T-72 that gained the larger legacy thanks to export sales while the T-64 was limited to Soviet territories due to its "state secret" status. The T-64 was then modernized to become the T-80 and qualities of the popular T-72 were included in this revised design.
The T-80 entered service in 1976 and became the primary MBT of the Soviet Army up until the collapse of the Soviet Empire in 1991. The T-80 was notable in its use of a gas turbine engine which promised higher power output over that of traditional diesel-fueled tank engines. However, the powerpack was never wholly reliable and proved more fuel thirsty, uneconomical and complicated to produce.
Realizing an uncertain world was now upon them, Russian authorities began debating the merits of producing and operating two similar-yet-different concurrent MBT solutions. As such, the focus fell onto developing a modernized form of the T-72 with key qualities of the T-80 to overtake the aging pair of fighting vehicles. The fire control system of the T-80 was mated to the T-72 frame while an autoloading facility was retained as was the proven 125mm smoothbore main gun - this amalgam creating the prototype designation of "T-88". The engine of choice fell to a diesel-fueled installation capable of 830 horsepower and the resulting product was then adopted as the "T-90", essentially an evolution of the original T-72 line.
Low-rate production of T-90 tanks began in 1993 and these were eventually followed by full-rate production vehicles beginning in 1995. Since then, some 1,670 T-90 tanks have been produced for Russia and several operators worldwide. Production is handled by the local concern of Uralvagonzavod based in Nizhny Tagil, Russia.
As in the T-72 before it, the T-90 utilizes a very low profile thanks to its two-man turret housing the commander and gunner (commander right, gunner left). The autoloader is of a carousel design perfected throughout the decades and feeds the projectile and charge from two separate rungs. As in previous Soviet tanks, the T-90 supports firing of guided anti-tank missiles from the main gun barrel and this can engage ground as well as aerial targets (helicopters). The driver is seated in the front-center of the hull with the turret immediately behind. The engine is situated in a rear compartment apart from the crew. The track system straddles the hull in the usual way and is dominated by its six double-tired, rubber-tiredroad wheels with the drive sprocket at the rear and the track idler at the front. Side skirt armor is a standard defensive measure seen on all T-90 tanks. The glacis plate is nearly vertical and adds basic protection against incoming enemy fire. Likewise, the turret is very squat with pointed edges, again providing a basic defense policy against incoming penetrating projectiles. The commander is afforded a raised cupola with vision blocks while the gunner manages his own turret roof hatch for entry/exit. Armor protection is a mix of steel and composites and further benefits from add-on Explosive Reactive Armor blocks ("Kontakt-5") providing protection from HEAT (High-Explosive, Anti-Tank), APFSDS (Armor-Piercing, Fin-Stabilized, Discarding Sabot) rounds, kinetic and chemical penetrators. Blocks are affixed to the hull front, sides and turret as required.
The armor scheme, fire control system and anti-missile measures are all descended from the T-80. An NBC (Nuclear, Biological, Chemical) protection system and night-vision equipment come standard. The "Shtora-1" anti-missile countermeasures suite is an optional fitting but nearly almost always incorporated to field units and serves to jam incoming signals such as those emitted from guided missiles. A laser warning receiver alerts the crew to tracking of the vehicle. The fire control system is fully digital and coupled to a thermal imaging device as well as laser rangefinder. Altogether, this allows for "firing on-the-move" as well as low-light activity. A dozer blade is hidden under the bow of the hull and can be used to clear obstacles while a mine-clearing plow can be added to the existing T-90 frame thanks to integrated connection points under the dozer blade.