During 1943, it became clear that the 75 mm gun mounted on the Pz Kpfw IV and Jagdpanzer IV was insufficient to deal with the T-34-85 and JS-2. To increase the firepower of the Pz Kpfw IV chassis, it was decided to mount the longer 75 mm gun of the Panther on the chassis instead. Weight and turret ring diameter limitations prevented the gun from being mounted in a turret. In stead, the Jagdpanzer IV was chosen to be upgraded with the longer gun.
Two versions of this vehicle, the Panzer IV/70 (V) and Panzer IV/70 (A), were made by the companies Vomag (already in charge of Jagdpanzer IV production) and Alkett (the company in chage of Sturmgeschütz III production), respectively. The main difference between the two was how the chassis was modified. The Pz Kpfw IV's fuel tanks were stored under the turret, so it was not possible to directly mount the gun in an armoured superstructure. Vomag chose to use the same method they used on the Jagdpanzer IV, by removing the driver's front plate and moving the fuel tanks to the rear. Alkett chose to keep the driver's front plate, increasing the total height of the vehicle. This made Alkett's version appear more box-like, and was generally a disadvantage: the taller vehicle was easier to spot, the additional armour made the already-stressed chassis 1.5 tons heavier and the vertical armour was less likely to deflect enemy shots.
Because most of the weight in both vehicles was added to the front, especially due to the much longer gun, the rubber on the road wheels on the forward-most boogies was churned off. To prevent this, all-steel road wheels were installed on some Panzer IV/70s on the forward-most boogie.
A total of 278 Panzer IV/70 (A) and about 950 Panzer IV/70 (V) were made during the war.
| Panzer IV/70 (A) | Panzer IV/70 (V) | |
|---|---|---|
| Crew | ||
| Crew |
|
|
| Physical Characteristics | ||
| Weight | 27 t | 25.5 t |
| Length | 8.87 m | 8.5 m |
| Width | 3.2 m | |
| Height | 2.2 m | 2 m |
| Armour | ||
| Armour (range) | 10-80 mm | |
| Performance | ||
| Speed (max) | 38 km/h | 35 km/h |
| Engine | ||
| Engine | Maybach HL 120 TRM | |
| Net h.p. | 300 | |
| Cylinders | 12 | |
| Displacement | 11900 cc | |
| Armament | ||
| Primary weapon | 7,5 cm Pjk 42 (L/70) (1) | |
| Secondary weapon | 7,92 MG 42 (1) | |
