The PT-91 Twardy ("hard","tough" or "resilient") is a Polish main battle tank designed by Obrum and manufactured by Bumar Labedy, Poland, to meet the requirements of the Polish and Malaysian Army. It is derived from the T-72M1 battle tank currently in service with the Polish Army.
The PT-91 was designed at the OBRUM (OBRUM for Ośrodek Badawczo-Rozwojowy Urządzeń Mechanicznych – Polish for Research and Development Centre for Mechanical Appliances) and is produced by the Bumar Łabędy company – part of Polish military consortium – Bumar Group.
Changes from the T-72 include a new dual-axis stabilized fire-control system, reactive armour, a more powerful engine, transmission and new automatic loader. Unlike many other T-72 upgrades the Polish Army PT-91s are upgraded using elements created almost exclusively by domestic companies (this includes new engine, fire control system and all communication system elements). Many of those elements were used to upgrade existing fleets of T-72 tanks in countries like in Czech Republic – T-72M4 CZ, Georgia – T-72SIM-1 or India – T-72 Ajeya Mk2.
Development
The development of the PT-91 began in July 1991 as part of the T-72 modernisation programme. The Ministry of Poland decided to upgrade the T-72 battle tank with a new fire control system and engine rather than purchasing extra Russian tanks for the Polish Army. The upgraded version of the T-72 was renamed the PT-91 Twardy. Bumar Labey is licensed to manufacture the PT-91 Twardy in the Poland region.
The battle tank features a steel anti-cumulative screen for displaying the route information and laser beams approaching the tank.
Armaments
The PT-91 Twardy is fitted with a single 125mm main gun, which can fire 42 rounds of ammunitions. It is also equipped with a 7.62mm coaxial machine gun and 12.7mm anti-aircraft machine gun, and 24 smoke grenade dispensers. The 12.7mm anti-aircraft machine gun and 7.62mm machine gun can fire 300 and 2,000 rounds respectively.
It is also incorporated with an autoloader, which reduces the workload of the tank crew. The autoloader can fire ammunitions at the rate of 10-12 rounds a minute. The traverse and elevation range of the battle tank is 360°, and +5.30° to +14° respectively.
Self protection
Erawa is advanced armour developed by the Poland Military Technical Institute for protecting the PT-91 from highly explosive grenades and missiles. It has been improved by eliminating the gaps between the bricks and offers better protection compared with explosive reactive armour (ERA). The armour occupies 9m² of space in the vehicle.
The modern laser warning system (LWS) identifies the laser beams used by the ATM launchers or missile guiding system. It protects the battle tank from missiles by automatically firing smoke grenades from two banks, each with six launchers. The commander can also fire these grenades manually.
Fire-control system
A fire control system comprising a gunner station is fitted in the PT-91 MBT. It has been modernised by replacing the soviet stabiliser with the TPDK-1, a stabiliser from Slovakia, which offers night-fighting capability.
The ballistic digital computer processes the information gathered by sensors, laser range finders, and manually inputs what is provided by the gunner or commander to determine the fire solutions.
The hunter-killer feature is obtained in the battle tank by combining both the gunner and commander station, which helps to track and destroy multiple targets quickly.
The integration of a dual-axis stabilised fire control system and electro-hydraulic gun stabilisation system can detect, identify, acquire and track a target efficiently, even in adverse weather conditions.
The crew compartment is equipped with an automatic fire suppression system (AFSS), integrated with infrared detectors that aid in detecting fire. The Halon 1301 suppresses any fire breakout in the compartment.
The engine compartment of the PT-91 is protected by an automated operating system that senses fire based on temperature-sensing Firewire and inhibits the fire with Halon 1211.
S-12U supercharged diesel engine
The PT-91 Twardy is powered by a single S-12U supercharged diesel engine, which can produce up to 634kW power. The S-12U is an advanced version of the Soviet V-46-6 engine; a modernised fuel and air injection system is responsible for increasing the power of the engine. The latest Twardy variants are fitted with 1000hp S-1,000 turbocharged engines.
PT-91 mobility
PT-91 can accomplish a maximum road speed of 60km/h. In the low gear, the vehicle can travel with 7km/h speed during low-speed manoeuvring. It has been designed to ford to a depth of 1.2m and 5m using torsion bar suspension. The Twardy can also cross rivers with water obstacles of 1m to 2m in depth without any preparation.
Variants
PT-91 Twardy
Production variant for Polish Army, extensively modernized development of T-72M1. Most of the vehicles are equipped with SKO-1M Drawa-1T dual-axis stabilized fire control system (with TES – Thermal Elbow Sight – total number of delivered thermal sights is 202) though some early production vehicles have a SKO-1 Drawa (with NV sight), Erawa reactive armour, a PCO SSC-1 Obra-1 laser-warning system and 850 hp PZL-Wola S-12U engine. The first 20 initial production vehicles were delivered to Polish Land Forces in 1993–1994 with another 78 full-scale production vehicles delivered 1995–1997, 135 modernized T-72M1 tanks (made in late 80s) delivered 1998–2002. Both new and modernized tanks have the same combat capabilities. Depending exact configuration Polish Army uses PT-91s in 3 variants PT-91, PT-91M and PT-91MA1.
PT-91A Twardy
Development variant with PZL-Wola S-1000 1,000 hp engine with mechanic transmission and number of other minor changes. Used for trials and as demonstrator on military exhibitions.
PT-91Z Hardy
(Z for Zmodernizowany – literally Modernized) Further development with SAGEM Savan-15 fire control system, according to life fire test Savan-15 has only minor advantage in accuracy over Drawa. The biggest advantage was a new gun stabilization system that gave the tank a significant increase in accuracy when the tank is on the move. Later it was used as a base to develop the PT-91M. This variant has won a number of stress tests in Malaysia over T-90, T-84 and K1 tanks, and has won the competition for a new Malaysian MBT. Only one prototype was made.
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| PT-91M tank of the Malaysian Army in March 2011 |
(M for Malaysia) — production export variant for Malaysia with Sagem Savan-15 fire control system, a new 1,000 hp powerpack with Renk automatic transmission bringing its top speed to 70 km/h. Its main gun have been changed to a ZTS 2A46MS 125 mm gun, a 7.62 mm FN MAG coaxial machine gun and a 12.7 mm FN Browning M2 HB AA machine gun. This variant is also equipped with Sagem panoramic sight, a Sagem laser gyro inertial navigation system, turret stabilisation system, Obra-3 laser-warning system, integrated with 81 mm smoke grenade launchers, CBRN warning and protection system, Thales communication systems. ERAWA 2 Explosive Reactive Armour, and German-made tank tracks. Two prototypes made (renamed PT-91E and PT-91Ex), 48 serial PT-91M Malaj vehicles produced 2007–2009.
PT-91E/Ex
(E for Export) – renamed prototypes of PT-91M used as demonstrators of export variant showed on military exhibitions. PT-91E is a first prototype named SP1 (it is same vehicle as shown on military parade in Kuala Lumpur in 2005), PT-91Ex is a second prototype named SP2. Both vehicles faced number of tests in Malaysia SP1 was used for traction tests and has made 7000 km offroad in Malaysia, SP2 2000 km and 500 shoots from main cannon. Very similar to PT-91M, offered for export to other countries.
PT-91P
(P for Peru) – Demonstrator for SITDEF Peru'2009 military exhibition. A cheaper alternative to PT-91Ex. This variant is equipped with newest PCO Drawa-TG fire control system with a thermal sight and modern communication system (Radmor RRC9310 radio, WB Electronics Fonet-IP communication system and Teldat battlefield management system). The vehicle was shown at a number of South American events including SITDEF Peru'2009 Expo.
PT-72U / PT-91U / PT-91EU
(U for Urbanizowany – Tank to fight in urbanized terrain) – Demonstrator for MSPO 2011 military exhibition. This is an offer for the Polish Army which involves certain modifications of the T-72 and PT-91 tanks. The modification includes installation of additional equipment, as remote-controlled cannon with an optical system, an omnidirectional observation system, add-on armour and further engineering equipment. For the weapons systems, the PT-72U is equipped with a remote controlled weapon station armed with a 12.7 mm machine gun, mounted to the crew commander hatch. The system had a fire rotation of 360° and an elevation angle for the gun from -5° to 55°. The observation system is equipped with 8 day-night cameras with the observation angle 55° and a rotary passive camera FLIR which has up to 26 times optical zoom. The armour package is composed by chassis and turret bar armour. The bottom of the chassis is equipped with reactive armour and add-on armour. The PT-72U is also equipped with a full range of new modern internal and external communication tools, which allow communication also via internet. There were also plans to modernize 84 Armenian T-72s to PT-72U standard.
Specifications
Entered service 1990s
Crew 3 men
Dimensions and weight
Weight 45.3 t
Length (gun forward) 9.53 m
Hull length 6.86 m
Width 3.59 m
Height 2.19 m
Armament
Main gun 125-mm smoothbore
Machine guns 1 x 7.62-mm, 1 x 12.7-mm
Elevation range - 6 to + 13 degrees
Traverse range 360 degrees
Ammunition load
Main gun 42 rounds
Machine guns 2 000 x 7.62, 300 x 12.7
Mobility
Engine S-12U diesel engine
Engine power 850 hp
Maximum road speed 60 km/h
Range 480 km
Maneuverability
Gradient 60%
Side slope 50%
Vertical step 0.85 m
Trench 2.8 m
Fording 1.4 m
Fording (with preparation) 5 m