The T-90 is a Russian third-generation main battle tank that is a modernisation of the T-72 (it was originally to be called the T-72BU, later renamed to T-90). It is currently the most modern tank in service with the Russian Ground Forces and Naval Infantry. Although a development of the T-72, the T-90 uses a 125mm 2A46 smoothbore tank gun, 1G46 gunner sights, a new engine, and thermal sights. Standard protective measures include a blend of steel, composite armour, Smoke mortars, Kontakt-5 explosive-reactive armor, laser warning receivers, Nakidka camouflage and the Shtora infrared ATGM jamming system. The EMT-7 electromagnetic pulse (EMP) creator is used in testing but not fitted to T-90s in active service. It is designed and built by Uralvagonzavod, in Nizhny Tagil, Russia. From 2011, the Russian armed forces have ceased ordering the T-90, and are instead waiting for the development of the Universal Combat Platform T-99 that is expected to enter service in 2020. T-90 can launch Tungsten alloy armor piercing fin stabilized discarding sabot (APFSDS).
Tungsten alloy armor piercing fin stabilized discarding sabot (APFSDS) is a type of ammunition which, like a bullet, does not contain explosives and uses kinetic energy to penetrate the target. The term can apply to any type of armor-piercing shot but typically refers to a modern type of armor piercing weapon, the tungsten alloy armo piercing fin stabilized discarding sabot, a type of long-rod penetrator (LRP), and not to small arms bullets.
The principle of tungsten alloy armor piercing is that it uses tungsten alloy armor piercing kinetic energy, which is a function of mass and velocity, to force its way through armor. The modern KE weapon maximizes KE and minimizes the area over which it is delivered by: maximizing the mass of whatever (albeit small) volume is occupied by the projectile—that is, using the densest metals practical, which is one of the reasons depleted uranium is often used, being fired with a very high muzzle velocity, concentrating the force in a small impact area while still retaining a relatively large mass.