The fact that the Polish PT-91 Twardy MBTs have already arrived in Ukraine, as a part of the military aid package, has been announced by Andriy Yermak, President Zelensky's Chief of Staff. In practical terms, the above means that another stage in the provision of military aid to Kyiv has begun. Earlier Poland had transferred more than 200 T-72M/M1/M1R MBTs. Some of the T-72 MBTs underwent a modification in Poland, involving the integration of a new thermal imaging system, and a new communications suite. In Ukraine, these tanks also received the Kontakt-1 ERA.
So far we do not know how many of those MBTs would be transferred. The Polish Armed Forces have operated 232 PT-91s in total, mainly in the 16th “Pomorska” Mechanized Division (three battalions), and the 12th “Szczecinska” Mechanized Division (an element smaller than a single battalion). A detachment sent to Latvia by the 21st Highland Brigade also uses the PT-91. That unit, customarily, has been equipped with T-72s. The MoD does not provide any comment on the involvement in Ukraine.
We do know however that many actions have been taken by the Polish Ministry of Defence to fill in the equipment gaps left after relevant assets were transferred east. 116 M1A1SA Abrams MBTs would be sent from the US, alongside the 250 brand new M1A2 SEPv3 MBTs procured back in April. Meanwhile, it is also expected that an agreement on the delivery of 180 K2 MBTs from Korea is signed this week, concerning the existing variant of that tank. Next, the Polish Armed Forces would receive several hundred K2PL MBTs, developed through industrial cooperation. The existing K2s would undergo relevant upgrades then. As stated by Mariusz Błaszczak, head of the Polish Ministry of Defence in his interview for "Sieci", he is still making effort to make Germany deliver a battalion of at least 44 Leopard 2A4 MBTs. The Germans have offered just 20 MBTs - this number had been earlier mentioned by CDU MP, Roedrich Kiesewetter.
Notably, the procurement of Abrams MBTs and the existing K2 MBTs sums up to 546 examples. This number is somewhat aligned with the total number of T-72s expected to be modified, and PT-91s (318 + 232 = 550). The MBT stockpile would be replenished then over the upcoming years, with the new MBTs being assigned to newly formed units. The Polish MoD is plausibly willing to restore the combat capabilities of the armoured elements with the new equipment, while the "depletion" shall be temporary and last only throughout the Russian involvement in Ukraine and/or, as the Russian Armed Forces would be recovering their capabilities during the post-war period. One should also note that both the US, as well as the UK have reinforced their armoured presence in Europe, following the outbreak of the Ukrainian conflict. For some time now, the 21st Highland Brigade has been working with British Challenger MBTs, while the United States has deployed an extra armoured brigade to Europe.
PT-91 MBT has been developed in the 1990s. It is a Polish upgrade of the T-72M1 platform - and the upgrade programme has been led by the Bumar-Łabędy facility. Some of these main battle tanks - 90 to 100 - were brand new, while most used the T-72A/M1 as the base platform. They have been equipped with the Polish ERAWA-1/2 ERA (ERAWA-2 offered some protection from tandem warheads), Obra laser warning receiver, and Drawa/Drawa-T fire control system. Most of the PT-91 MBTs feature thermal imaging systems - the Israeli systems used initially have started to be gradually replaced with the proprietary KLW-1 Asteria system, as of 2014. The MBT also features a tuned-up S-12U engine.
The main disadvantage the PT-91 had was its obsolete 2A46 gun and the less capable stabilizer unit - having a major impact on the capability to engage when on the move. A new 2A46MS gun, a 1000HP engine, a new gearbox, and French Savan-15 FCS have been fitted on the PT-91M Malay variant, exported to Malaysia. A few years back, an in-depth upgrade of the PT-91/T-72M1 was proposed by Bumar, but it all ended up in an agreement, signed in July 2019, on overhauls and modifications of the T-72 MBT, designated T-72M1R.
Any transfer, even of a minor quantity of Twardy MBTs to Ukraine should provide a major boost to its capabilities. These MBTs would also be easier to train and maintain, than any of the western MBTs. We should only hope now that the Polish MoD would be quick to commission a successor.