To combat the new German anti-tank weapons, the T-43 medium tank has the armour of a heavy tank, while retaining the speed of the original. The first two prototypes were finally completed in March 1943 and went through trials in August. As a result, the T-43 was recommended for production to replace the T-34. They could have been in combat in significant numbers by the end of the year. However, the appearance of large numbers of German heavy Tiger, Panther and Ferdinand tanks at Kursk highlighted that a bigger gun was more important than heavier armour. As the T-43 was already at its weight limit, the T-43 turret, re-armed with a long 85mm gun, was fitted to the T-34, while the T-43 was redeveloped into the T-44.