Pz.Kpfw.IV vs StuG

 "Top Secret

Inspector General of the Tank Forces
#046/44 Top Secret

June 26th, 1944

Copy 1 out of 5

Notes on the report to the Fuhrer

Replacement of Pz.Kpfw.IV tanks with L/48 and L/70 assault guns.

1) Tactical-technical data

The 75 mm L/48 gun with the model 1939 armour piercing shell can penetrate all known types of English, American, and Russian tanks from medium distances of 600-1200 meters (including the English Cromwell tank, see attachment #1).

Reports from Sicily, Italy, and Normandy regarding the use of Pz.Kpfw.IV tanks in combat compared to assault guns unanimously state that the tactical-technical data of the assault guns is considerably lower than that of the Pz.Kpfw.IV tank on coastal roads, in mountainous regions, and in the Normandy bocage, as firing sideways can only be done along a limited arc. The terrain makes aiming in situations where the assault guns have to turn their entire hull impossible, thus severely limiting the effectiveness of their use.

According to a report by Thomale from Paris based on newest combat experience data and reports from the Tank Inspector attached to the Commander of the Western Front, the use of assault guns in combat among ditches and the bocage in Normandy is difficult since their bore axis is too low. The tank has a higher bore axis and rotating turret and can thus fire both from roadside ditches and through the bocage.

2) Losses

Greater losses in Pz.Kpfw.IV tanks compared to the assault guns are explained primarily by the very different tactics that they use. The assault gun mainly fights with the speed of infantry, but the tank is used as an offensive weapon within a fully motorized tank unit.

In connection with this, more tanks go out of action for technical reasons alone, as the pressure on their running gear is greater due to higher speeds.

The assault gun fights primarily alongside infantry, while the tanks ram into enemy lines. The maneuver tactics of tank forces are unthinkable without a rotating turret. One must also note that if an assault gun's running gear is disabled and it becomes immobile, it will also become incapable of combat, whereas a tank that is stuck somewhere or immobilized can still fight thanks to its rotating turret.

3) Tactical data

1. The Pz.Kpfw.IV tank is presently a well established tank design that every tanker has utmost faith in. The assault gun on the Pz.Kpfw.IV chassis is a temporary measure at best, as it is considerably inferior to the assault gun on the Pz.Kpfw.III chassis.
2. The final drives are the Pz.Kpfw.IV's weak point. Since the assault gun aims by traversing the entire hull, the load on the brakes and final drives is increased, thus the widespread breakdown of final drives is observed.
3. There is a shortage of spare Pz.Kpfw.IV final drives.
4. Moving from Pz.Kpfw.IV to assault gun production will further exacerbate this shortage as the number of final drive breakdowns will no doubt increase.
   Moving from the L/48 to the L/70 gun will only increase this tendency because of the considerable increase in load on the frame (overloading the casemate).
5. On the initiative of the Inspector General of the Tank Forces, the L/70 gun is being installed on Vomag tank destroyers on the Pz.Kpfw.IV chassis. Colonel Audersch reports that production will begin in late August.

Conclusions

1. All reports from units unanimously state that a tank with a rotating turret is superior when fighting in a tank unit. There is not a single report of the opposite.
2. All known enemy tanks and assault guns are vulnerable to modern armour piercing armament including the 75 mm L/48 gun.
3. Transitioning from production of Pz.Kpfw.IV tanks to assault guns will require shipping assault guns to Pz.Kpfw.IV battalions in order to keep up their numbers. This will result in having to split Pz.Kpfw.IV battalions into groups of two different vehicles with different tactical applications.