PT-91 Twardy

PT-91 "Twardy"
PT-91
Type	Main battle tank
Place of origin	Poland
Service history
Used by	See Users
Specifications
Weight	45.9 tonnes
Length	6.95 m (9.67 with barrel in forward position)
Width	3.59 m
Height	2.19 m
Crew	3
Armor	composite armour; front and side armor laminated; front, side and top armor behind Erawa-1/Erawa-2 ERA, steel side anti-cumulative screens
Main armament	1 × 125 mm 2A46M (D-81TM) gun (42 rounds)
Secondary armament	1 × 7.62mm PKT coaxial general-purpose machine gun (2,000 rounds) 1 × 12.7 mm NSVT heavy machine gun (300 rounds)
Engine	PZL-Wola S-12U diesel 850 hp (634 kW)
Power/weight	18.5 hp/tonne (13.8 kW/tonne)
Transmission	Manual
Suspension	torsion-bar
Ground clearance	395 mm
Fuel capacity	1,000 l
Operational range	650 km (700 km with extra fuel tanks)
Speed	60 km/h

PT-91M "Pendekar"
PT-91M "Pendekar" of Malaysian Army on display
Type	Main battle tank
Place of origin	Poland
Service history
Used by	Malaysia  Poland
Specifications
Weight	48.5 tonnes
Length	6.86 m (10.03 m with barrel in forward position)
Width	3.70 m
Height	2.60 m
Crew	3
Armor	composite armour; front and side armor laminated; front, side and top armor behind Erawa-1/Erawa-2 ERA, steel side anti-cumulative screens
Main armament	1 × 125 mm 2A46MS gun (40 rounds)
Secondary armament	1 × 7.62mm FN MAG coaxial general-purpose machine gun (2,000 rounds), 1 x 12.7 mm FN M2 HB anti-aircraft heavy machine gun (250 rounds)
Engine	PZL-Wola S-1000R diesel 1,000 hp (735 kW)
Power/weight	20.6 hp/t (16 kW/t)
Transmission	Automatic RENK-SESM/ESM-350M
Suspension	torsion-bar
Ground clearance	395 mm
Speed	70 km/h

The PT-91 Twardy ("resilient") is a Polish main battle tank. A development of the T-72M1, it first entered service in 1995. 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, a part of the Bumar Group, a Polish technical military consortium. 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, including a new engine, the fire control system and all communication system elements. Many of those elements were used to upgrade existing fleets of T-72 tanks in countries including the Czech Republic (T-72M4 CZ), Georgia (T-72SIM-1) and India (T-72 Ajeya Mk. 2).

In the late 1980s the Polish Army modernized all of its obsolete T-55 tanks to the T-55AM Mérida standard. The successful conversion convinced the General Staff that similar modernization could also be applied to other Soviet-designed tanks made in Poland and used by the Polish Armed Forces. In late 1988 it was decided to prepare a project of modernization for the T-72M1 design – using the experience from production of licensed T-72M (obiekt 172M-E3 – Polish army designation T-72), T-72M1 (obiekt 172M-E5), T-72M1K (Polish army designation T-72M1D).

The Gliwice-based Research and Development Centre of Mechanical Systems OBRUM (Polish: Ośrodek Badawczo-Rozwojowy Urządzeń Mechanicznych) was chosen as the main design bureau. However, initially the work progressed at a very slow pace, mainly because the Polish General Staff was also considering the purchase of a newer version of T-72 (T-72S) or the modern T-80.