Russo-Ukrainian War: The PT-91 Twardy Main Battle Tank

Source: Ministry of Defense of Ukraine

     Starting in April 2023, the Ukrainian Army began receiving the PT-91 Twardy (“Hard”) main battle tank as part of Poland's sizable military contribution to Ukraine. In all, sixty tanks have been provided. The PT-91 is derived from the T-72M1 which is a Polish license built T-72A, the latter's production having started in 1983. Development of the PT-91 started in 1991 and the objective was to modernize the T-72M1 using as many Polish produced components as feasible in order to be as independent from imported matériel as possible. In 1993, a purchase order was placed for twenty examples for field trials and after acceptance, the first production PT-91 tanks reached Polish armor units beginning in 1998. In the photograph, the crew of a PT-91 belonging to the 22nd. Mechanized Brigade “Mykolaiv” performs repair or maintenance on the running gear.

     Power for the 46-ton PT-91 comes from the S-12U, 12-cylinder, water-cooled, turbocharged diesel engine that generates 850 horsepower. Built by PZL-Wola, the S-12U is a Polish variant of the old Soviet 780 horsepower V-46-6 diesel engine. The S-12U features a updated fuel injection system along with air injection system to more efficiently burn off exhaust gases. This engine is mated to a manual transmission with an 8-speed gearbox (7 forward, 1 reverse). The top road speed the PT-91 can attain is 37 miles per hour while 264 gallons of diesel fuel give the tank a maximum operational range of 403 miles. If fitted with external fuel tanks, the operational range increases to 434 miles.

     For a main armament, the PT-91 uses the exact same 2A46 125mm smoothbore gun as the T-72M1. However, the Soviet-era 2E28M 2-plane gun stabilizer is replaced with a more modern stabilizer produced in Slovakia (one of the few imported components) which is tied into the tank's SKO-1M Drawa-1T FCS (Fire Control System). The Drawa-1T FCS is a suite which includes the PCD gunner's sight, the TES thermovision night sight (developed by the Israeli company El-Op), a POD-72 commander's day/night sight, laser rangefinder, and a ballistic computer. The latter calculates the targeting requirements based on the tank's speed, the target's speed, weather conditions, the type of round being fired, and even the temperature of the round. The output is displayed on a monitor and the computer will even state when the probability of a successful hit on a target is minimal. Like the T-72M1, the PT-91 uses a automatic loader which is fed via a ammunition carousel located beneath the turret. A total of 42 rounds of ammunition are carried. This provides for a maximum rate of fire between 8 to 10 rounds per minute. The turret provides 360 degrees of traverse for the 2A46 while the gun mount offers a maximum elevation of 14 degrees and a maximum depression of 6 degrees.

     The 2A46 can fire a multitude of ammunition types. An example of a APFSDS (Armor-Piercing, Fin-Stabilized, Discarding Sabot) round is the 3VBM11 which can penetrate 410mm of RHA (Rolled Homogeneous Armor) at a 0 degree slope at a range of 1.2 miles and with a 60 degree slope, the penetration is 200mm. The 3VBK27, a HEAT (High-Explosive Anti-Tank) round, can drill through 350mm of armor at a 60 degree slope out to 1.8 miles. The more standard 3VOF22 HE (High-Explosive) round can be fired out to a range of 2.5 miles. The PT-91 is not believed to be capable of using the Russian 9M119 Svir (NATO reporting name AT-11 Sniper) tube-launched, laser guided anti-tank missile. 

     Secondary armament includes a coaxial 7.62mm PKT machine-gun provided with 2,000 rounds and a 12.7mm NSVT heavy machine-gun fitted to a pintle mount next to the commander's cupola on the turret. A total of 300 rounds for the NSVT is typically carried.

     The effective armor protection of the PT-91 and its crew of three (commander, driver, and gunner) is not specified but the standard thickness (not accounting for sloping) of the T-72M1 upon which the PT-91 is derived from sports 220mm thick front hull armor, 240mm of armor on the turret front, 200mm on the sides and rear of the turret, and up to 190mm of armor on the hull sides and rear. On the upper hull front, 16mm thick high hardness steel armor is added to boost protection. The PT-91 utilized by Ukraine are fitted with the distinctive Polish developed ERAWA-1 explosive reactive armor (ERA). It is characterized by having more squarish blocks (rather than the rectangular blocks used by the common Russian Kontakt-1 ERA) and with barely any gap between the blocks when mounted. A complete ERAWA-1 arrangement consists of a total of 394 blocks arranged on the turret, front upper hull, and sides. ERAWA-1 will not be triggered by being hit by small arms calibers nor by light cannon rounds up to and including 30mm ammunition. ERAWA, assuming it is struck by a incoming munition, offers between 95% to 100% protection against HEAT rounds from weapons such as the RPG-7. Against larger HEAT munitions, the protection is still excellent with a 65% to 70% protection versus the 125mm HEAT round and anti-tank weapons such as the Swedish AT4 (which is utilized by the Ukrainian Army). However, like any ERA, it is susceptible to defeat by tandem-charge warheads.

     Other defensive systems include the PCO SSC-1 Obra-1 laser warning system. The Obra-1 consists of four sensors on the exterior of the hull and these can detect when the tank is “painted” by laser rangefinders or laser illuminators which are used most often by laser guided anti-tank missiles. These sensors are tied into a control unit with a display for the crew. In addition, the PT-91's smoke grenade launchers, 24 in all, are also tied into the control unit. When set to automatic, if the tank is painted, the Obra-1 detects the direction, warns the crew, and triggers the grenade launchers to fire and create a smoke screen between the tank and the origin of the laser. With the crew taking evasive action and the smoke degrading the laser's effectiveness and obscuring the missile operator's view, the Obra-1 offers a higher survival chance against laser guided missiles. It is possible for the Obra-1 to work semi-automatically in which the tank commander decides if the smoke grenades are launched and there is also a manual mode in which the Obra-1 simply warns of the “painting” and from what direction and the commander then has to determine which grenade launcher battery to use in addition to firing them. Besides smoke grenades, the launchers can be fitted with non-lethal tear gas grenades or fragmentation anti-personnel grenades. Further defensive equipment has the crew and engine compartments fitted with automatic fire detection/suppression systems and NBC (Nuclear Biological Chemical) protective apparatus. The PT-91 can also generate a smoke screen by dumping fuel onto the hot exhaust.

     Finally, the driver's station is equipped with a US-DK-1 panel which provides the driver with full control over the tank's systems and also it can run and display diagnostic test results onto a display. For night driving, the station is equipped with a Radomka passive night sight.

     As of January 2025, the Ukrainian Army has lost a total of eleven PT-91 tanks.

Russo-Ukrainian War: T-80BVM obr. 2022

Source: Reddit.

     A Russian T-80BVM obr. 2022 belonging to the 67th. Motorized Rifle Division (the unit's tactical symbol is on the side of the turret), displaying a rather extensive array of passive and active defenses. It is being transported by what looks to be a KamAZ-65225 tank transporter and was photographed sometime in January 2025. The T-80BVM is a modernization of the T-80BV which first appeared in service with the Soviet Army in 1985. The first T-80BVM made its public debut in 2017.

     Power for the 46-ton T-80BVM comes from a GTD-1250TF gas turbine engine that develops 1,250 horsepower and can propel the T-80BVM along roads at a maximum speed of 43 miles per hour and off-road, up to 34 miles per hour terrain depending. The GTD-1250 consumes fuel at a very high rate and had a much higher production cost in comparison to a standard diesel engine. Thus, the T-80BVM has a maximum cruise range of 208 miles (via 290 gallons of onboard fuel) and as such, the tank is often equipped with two external fuel tanks (total of 195 additional gallons) to increase the range to 310 miles. The engine is paired to a manual planetary transmission with a 6-speed gearbox (5 forward, 1 reverse). The external fuel tanks are secured to racks on the rear of the tank and here, they are not present.

     The main armament is a 2A46M-5 (or 2A46M-4 in some sources) 125mm smoothbore cannon which is mounted to a 2-axis, electro-hydraulic 2E26M stabilizer. The turret provides for 360 degrees of traverse while the gun mount allows for a maximum of 14 degrees of elevation and up to 5 degrees of depression. As with most Russian tanks, the cannon is provided with a updated Korzina automatic loader which is fed from a carousel that sits beneath the turret at the bottom of the hull. It holds 28 rounds of ammunition and with it, a rate of fire between 4 to 6 rounds per minute is possible. A further 17 rounds of ammunition are carried, kept both in the turret and hull, along with 6 Refleks-M missiles (see below). Accuracy is aided by a 1A45T Irtysh fire control system (FCS). The gunner is provided with a stabilized Sosna-U sight which incorporates a day sight, thermal sight, laser rangefinder, and a ballistic computer. Some late T-80BVM may utilize the PNM-T sight which is Sosna-U alternative built from wholly Russian components. Typical ammunition used includes APFSDS (Armor-Piercing Fin-Stabilized Discarding Sabot), HE (High-Explosive), and HEAT (High-Explosive Anti-Tank) rounds plus the 9K119M Refleks-M tube-launched, laser guided anti-tank missile (NATO reporting name AT-11 Sniper). The 3BM59 “Svinets-1” APFSDS round can penetrate around 315mm of RHA (Rolled Homogeneous Armor) at a 60 degree slope at 1.2 miles. At a 0 degree slope, the 3BM59 can penetrate 540mm of RHA at the same range. The 3BK31 HEAT round can penetrate 350mm of RHA at a 60 degree slope at a range of 1.9 miles.   The 3OF26 HE round can be fired out to a range of 2.5 miles while the Refleks-M can attain a range of 3 miles and drill through a maximum of 700mm of armor at a 90 degree slope after ERA (Explosive Reactive Armor) thanks to its tandem charge warhead. The gunner provides the guidance to target using a modulated laser beam. Secondary armament consists of a coaxial PKT 7.62mm machine-gun while mounted on the turret near the commander's hatch is a NSVT 12.7mm heavy machine-gun. 1,250 rounds of ammunition are available for the PKT while a total of 300 rounds are carried for the NSVT of which 50 rounds is ready ammunition.

     For protection, the T-80BMV uses composite armor on the hull and turret with the cheeks of the turret having additional defense called Combination K which consists of a cavity filled with ultra-porcelain ceramic rods arranged in a matrix. This gives the turret front the equivalent of 550mm of steel armor. The front glacis plate uses a sandwich-style of composite armor consisting of an outer layer of 80mm thick steel which is backed by 105mm of glass-reinforced plastic then a 20mm thick base layer of steel armor. This gives the front hull of the T-80BMV the equivalent of over 500mm of armor. In addition to the base armor, the T-80BMV utilizes Relikt explosive reactive armor (ERA) blocks on the upper front hull, turret front, hull sides, and the top of the turret. Cage armor is fitted to the rear of the tank hull, offering a measure of protection to the engine compartment from HEAT munitions. The T-80BVM can be fitted with 4S24 Karkas ERA and this is the case here in the photograph in the form of large metal blocks on the turret sides and here, unusually, on top of the side Relikt ERA. The crew has added rubber and mesh appliqué armor to the turret sides and front plus ad-hoc bar armor to the rear area of the turret. In addition, the crew has created a large anti-drone cage consisting of metal framing with what looks like chicken wire. Additional defense comes from a 902B Tucha smoke grenade launcher system consisting of two banks of four launcher tubes on the turret sides. The T-80BMV can also be fitted with active protective systems such as Arena but it is not standard. Atop the anti-drone cage are antenna for drone jammers, added there by the crew rather than it being standard.

     Other systems of the T-80BVM include a TVN-5 night sight for the driver, internal crew intercom system, TKN-4S Agat-MR day/night sight & TKN-3M day sight for the commander, automatic fire suppression system, PDT-7151 auxiliary sight, DVE-BS turret roof mounted meteorological sensor, R-168 series VHF radio station, and a ZETS-11-2 NBC protection system (Nuclear Biological Chemical). 

     The T-80BVM obr. 2022 specifically uses Kontakt-5 ERA on the turret roof to provide for more protective coverage and cage armor is added to the rear of the hull and turret (though only the rear hull piece appears intact). Another feature of the T-80BVM obr. 2022 is the removal of the rear side cage armor and replacing it with Relikt ERA panels. Finally, Relikt ERA is built into the tank's front mud guards. Some T-80BVM obr. 2022 tanks may have elderly 1PN96MT-02 thermal gun sights due to shortages of the Sosna-U.