Staff Writer (Updated: 2/14/2016):
The T-72 originated as a design to counter the expensive nature of the technologically-advanced T-64 of 1963. The T-64 was the primary spearhead Soviet Main Battle Tank and introduced the D-81T 125mm smoothbore main gun. To this point, Western offerings relied on a rifled 105mm system and have since gone on to adopt a 120mm smoothbore design themselves. The T-64 also coupled the 125mm main gun with an automatic loader which reduced the crew size to three and contained overall operational weights to manageable levels while promoting a reduced profile on the horizon. The T-64B was the first Soviet tank line to support firing guided anti-tank missiles from the main gun barrel which broadened its tactical value considerably. However, its procurement costs proved limited and only 13,000 T-64 tanks were produced from 1951 to 1962 from plants originating in Russia, Belarus, Ukraine and Uzbekistan.
The prototype T-72 was born as the "Object 172" which evolved into the modified "Object 172M". Evaluations of this new vehicle were undertaken in 1971 and concluded the tank to be functional and capable, leading to its adoption as the "T-72" for the Red Army. Serial production began that same year, quickly replacing the T-55 and T-62 in production, and formal deliveries occurred the following. The T-72 was first unveiled to the public in the 1977 "May Day" parade and, amazingly, would retain its frontline status until the collapse of the Soviet Empire in 1991.
Externally, the T-72 followed the tried-and-true doctrine of decades-long Soviet tank design. Much attention was always given to a very low profile from any angle and the addition of an autoloading mechanism lessened the turret crew to two personnel with the driver in the front-center of the hull (Western tanks generally utilize manual loading which required a fourth crewmember, a third person in the turret). The autoloading feature was devised as a carousel-type arrangement containing the charge in an upper rung and the projectile in a lower rung, brought together at the breech. The gunner could then respond to the commander's load and fire orders by electronically selecting the appropriate projectile and readying the main gun in this fashion. The commander's cupola was offset to the right of the turret roof and came complete with vision blocks. A integrated dozer blade was affixed to the underside of the bow to help plough tank obstacles or fill in anti-tank ditches with earth or sand.
The T-72 utilized a 125mm D-81TM (2A46M) smoothbore main gun and this instrument could fire a healthy dose of projectile types (39 maximum carried aboard) including HEAT-FS (High-Explosive, Anti-Tank - Fin-Stabilized), HE-FRAG (FS) (High-Explosive-Fragmentation (Fin-Stabilized)) and APFSDS (Armor-Piercing, Fin-Stabilized Discarding Sabot) . Common to other Soviet/Russian tanks, the T-72 main gun could also fire a guided anti-tank missile from the barrel (later models). To counter any potential armored/unarmored battlefield threat, usually a mix of projectiles was carried by all Red Army T-72 tanks. A 12.7mm NSVT anti-aircraft machine gun could be fitted at the commander's cupola position for countering low-flying threats such as helicopters and engaging lightly armored ground vehicles. A 7.62mm PKT series coaxial machine gun was a standard fitting alongside the main gun in the turret and actuated by the gunner. A self-generated smokescreen could be set through 12 x smoke grenade dischargers located along the frontal sides of the turret.
Running gear for the T-72 consisted of six double-tired road wheels to a track side. The drive sprocket was at the rear while the track idler was at the front. The upper track portion was covered by side skirt armor for basic defense against enemy fire. The engine was situated in a rear compartment apart from the fighting cabin and consisted of a 12-cylinder diesel fueled installation outputting at 780 horsepower running at 2,000rpm. The engine was aligned with a hydraulic synchromesh transmission system featuring seven forward speeds and a single reverse speed. The track support system was tied to a torsion bar suspension system offering excellent cross-country mobility. Maximum listed road speed was between 37 and 40 miles per hour on ideal surfaces (less when going offroad) with an operational road range of 250 to 290 miles. External fuel drums could be affixed to the rear hull, helping to improve operational ranges out to 430 miles.