"Buff my tank!" - Panzer IV

By Zarax

Hello and welcome to the third edition of "Buff my tank!"

The "Buff my tank!" articles are meant as an historical way to look at some tanks considered underpowered in game and ways to improve their combat abilities discussed by the original german engineers.
Beware that while being sometimes ironic in tone, the article treats about both costs and benefits of every choice and it most likely will never be listened by WG as suggestion.

 Panzer IV is yet another excellent "MMO tank", which saw a good deal of upgrades and plans during its service life. Even in its WOT life it saw a pretty big transformation, where the turret often mentioned as "vaderturm" with the 75mm L/70 removed and replaced with a close combat focused configuration.

Currently this tank is not exactly seen as weak but it is still controversial as many consider it dependent on HEAT rounds to be truly competitive, an extra edge that some even consider excessive.
Still, this popular tank was the object of many engineering projects, often left in the drawer.
Panzer IV & its variants by Spielberger plus some material from Panzer Tracts 20-1 will be used as historical support for this article.


 This time we will take a slightly different approach and divide the possible upgrades by section.

Protection:

One often heard complaint is about insufficient protection, leaving the tank vulnerable to almost anything that shoots at it, especially with the new top turret. Side skirts were often suggested, but their contribute to armor against direct shots would be minimal, while artillery is not yet a problem at this level.

Another problem is of course the flat armor, something that makes shot deflection even more unlikely and angling discarded due to weak side armor.
In this respect, an alternate Panzer IV H was proposed in drawing W1462:

A sloped 80mm front would have given the tank excellent protection and with the long gun it would have been competitive until the end of the war, and Hitler asked this to be increased to 100mm.

Unfortunately this design was estimated to bring the weight to over 28 tons, which was too much for the suspensions.

This would of course leave the turret still weak, but there is room for improvement.

The best known project is the Panther narrow turret on Pz IV chassis, but this configuration was already deemed not balanced by WG:

A more realistic although still effective solution would be to use Krupp AKF31941turret drawing:

This would still give an excellent turret front without looking like a certain famous helm, although it's likely there would have been just a manual traverse system for it.

Mobility:

The late war Panzer IV was already an overweight tank and WG took all possible steps to improve it from historical stats.
One historical plan was to install a torsion bar suspension on Panzer IV chassis. This was designed by Kniepkamp, who later will be one of the inspirators of the E-series.
This could have helped with the increasing weight, as well as the interleaved wheels and larger tracks discussed later.
However, all of this is already in WOT in one form or the other, thus making this section nearly redundant.

Firepower:

Historically, the best cannon mounted on a production Panzer IV was the 75mm L/48.
The experimental 75mm L/70 is the most known configuration and this was also attempted to mount in the standard Pz IV turret.
Tests gave negative results, although it's possible a rigid mount like the one tried in the Hetzer could have worked.
This wouldn't be without drawbacks though, as a much heavier gun coupled with the necessary turret reinforcements would result in a significant hit in tank ergonomics.

A possible realistic alternative for large guns would be to use the Heuschrecke 10 turret:

This would realistically allow for larger guns (including the 105 L/28 as shown) while keeping weight acceptable.

Of course there is a price to pay, in this case a maximum turret armor of 30mm.

The last, more exotic solution would be to opt for something completely different:

A Mk 103 autocannon coupled with two 75mm recoilless rifles would have given this prototype a pretty respectable firepower, but we'll never see this configuration in WOT (although it would be a decent grinding gun). Twin 30mm as in the "Kugelblitz" configuration would make the tank a feared "knife fighter" as well.

Going into extremes, the 3.7cm flak 43 could be used as well, possibly in a similar configuration as the Mk103.

Nearly going into science fiction but still possible: Tungsten APCR used as silver rounds would have decent penetration, while uranium rounds were also available:

It also is very likely that the 8H63 and 10H64 guns were proposed as well in the Krupp november 1944 panzer rearmament project, but by that time all Pz IV plans were discarded.

Conclusion:

Historically, the Panzer IV was optimized to the very limits of its chassis and any further improvements would have necessitated of a deep redesign, something that the germans never afforded during the war, especially later on when the Panther chassis was only slightly more expensive for vastly better performance.

By combining various proposed improvements one could make a compact heavy tank with great firepower and armor but bad mobility or an excellent but very vulnerable sniper.

This leads for the final verdict: 

Any improvement in one area would lead to weakening something else, thus only a "focus shift" would be likely.

Something very similar to Heuschrecke 10 is planned for the open top TD tree, while combining the sloped chassis with the Panther turret and 75mm L/70 would imho make a slow but rather interesting possibility for a tier higher, although with extremely bad mobility.

Thank you for reading and see you in the next article!