Tanks Military
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 the 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.
The PT-91 Twardy 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.
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 the 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.
After the political changes of 1989 and the dissolution of the Soviet bloc, Polish-Soviet talks on purchase of modern tanks came to a halt and the design of a new Polish tank gained momentum. The first design proposed by the bureau was code-named Wilk (Polish for wolf), but the project was canceled. Instead, the priority was shifted to a different project named Twardy. The basic aim of the conversion of T-72 was to adapt it to the reality of modern warfare and fix its most visible deficiencies. Among those were low mobility, insufficient armour, lack of a fire control system and poor stabilisation of the main gun, which resulted in poor firing accuracy. An additional problem was the lack of passive night vision aiming systems.
Starting from July 1991 T-72 modernization programs were implemented by the Bumarcombine which had been producing T-72s under Soviet license. The modernized main battle tank was designated PT-91 Twardy. From base modification, it differs in increased protection, fire control system and engine. In 1993 the Polish Defense Ministry ordered 20 PT-91 tanks to be used for field trials and Armed Forces tests.
Starting from July 1991 T-72 modernization programs were implemented by the Bumarcombine which had been producing T-72s under Soviet license. The modernized main battle tank was designated PT-91 Twardy. From base modification, it differs in increased protection, fire control system and engine. In 1993 the Polish Defense Ministry ordered 20 PT-91 tanks to be used for field trials and Armed Forces tests.The main battle tank's protection from high-explosive anti-tank (HEAT) projectiles and missiles is increased by the new Erawa dynamic armor developed by the Poland Military-Technical Institute. This protection consists of 394 tiles with explosives, detonating in case of a direct hit. The tiles cover 9 m2 on the tank. 108 tiles are placed on the turret, 118 on the hull and 84 on each side's anti-HEAT screens. The Twardy uses steel anti-HEAT screens instead of the rubber used on the T-72. Erawa's main difference from the Soviet analogs is that Erawa's containers fit almost without gaps while on the Soviet modernized T-72 gaps reach 10–15 mm noticeably decreasing defense effectiveness. There are two Erawa modifications: Erawa-1 and -2, differing in weight of the explosives. More details
