Panzer IV turret armour

[cbo]

In another thread, lmp wrote:

Cbo
Slightly off topic but as you seem to know quite a bit why did the PzMkIV recieve minimal improvements to its turret armour. Was this due to the fact that the long barrel 75 was a tight squeeze meaning the glacis could not be improved, in other words the turret was at its design limits or maximum weight for traverse possibly?

Late war it was not a great tank to have on the defence either dug in or on a hill due to the comparativly weak turret.

AFAIK it was a matter of balance in the turret. Because the commander was placed behind the gun, the gun had to be mounted as far forward as possible. This unbalanced the turret to the point where it was impossible to increase the thicknes of the turret front armour and stil have a working turret.
There was a proposal for a new turret in 1944, which moved the commander behind the gunner, allowing the gun to be moved back and the turret front armour to be increased to 80mm IIRC.

The turret never materialized, probably because the Germans were intent on ending Panzer IV tank production in the summer of 1944. Same thing killed off a number of other proposals for improving the Panzer IV.
Instead, money was put on the Panzer III/IV hybrid, which never materialized either.

cbo

[Marek_Tucan]

Would that (turret imbalance due to bigger gun weight) be also a factor with PzKpfw IIIN? It seems it got weaker front turret armor compared to IIIL/M.

[Imp]

Cheers cbo that makes perfect sense it would be so out of balance the traverse mechanism would fail.

[cbo]

Would that (turret imbalance due to bigger gun weight) be also a factor with PzKpfw IIIN? It seems it got weaker front turret armor compared to IIIL/M.

Ausf. Ns were mainly based on Ausf L and M and had the same turret as they did, AFAIK. My references give a turret front thickness of 57mm for both types as well as Ausf. N.
But most of the front turret on these Panzer IIIs were covered by the mantlet, which in the vehicles armed with the 50mm gun was 50mm + 20mm spaced armour. The Ausf. N did not use spaced armour on the mantlet and thus had a 50mm thick mantlet.

The 7,5cm L/24 gun weighed 490 kg and the 5cm L/60 435 kg so they might have decided to save some weight by removing the spaced armour on the turret. Or perhaps they just didn't bother putting it on.
The Panzer III was the only German tank were spaced armour was used exensively and even though the armour on the Panzer IV was just as thin, only a few ever got that feature. So perhaps they just decided against it when they made the Ausf. N.

cbo