The weakest point on the welded turret had been found to be the lower chin of the turret front.
To reinforce this and at the same time to simplify production, the lower corner was simply cut off and a single flat plate of thicker armor welded in its place.
The modified F-34 gun mantlet provided by Barrikady came to a sharp point in contrast to the blunt nose type produced at Zavod Nr. 92 in Gorki.
STZ benefitted from the modernization program initiated by Morozov's GKB-T-34 but their production model was something of a hybrid, hence it has been referred to here as the T-34 Model 1941/42.
This variant used many of the new features developed for the simplified Model 1942, e.g. the new river's hatch and the improved tow hooks.
The noticeable exception was in the rear area, where the old rounded-off hull was retained as was the rectangular access port.
A modification of the STZ type appeared on the Volkhov Front and in Leningrad.
These T-34s were fitted with added armor plate ("(z Ekranami)") on the hull front and sometimes on the turret sides and front as well.
These were STZ-produced machines, but the modification work was done in Leningrad at Repair Zavod Nr. 27.
Source : Steve Zaloga, "T-34 in action", Squadron-Signal Publ.