Panzer IV/70 (V) at AusArmourFest 2024. German SPG.

Prior to WW2, German Tank leader Heinz Guderian had predicted the need for highly mobile self-propelled anti-tank vehicles, later known as Panzerjäger (tank hunters), within the German order of Battle. The towed-type of anti-tank gun developed for use in the Anti-Tank Companies within Panzer Divisions would be outpaced by fast moving Panzer Companies, and would be too slow to effectively respond to armoured counterattacks from enemy units. For this reason, in March 1940 the first attempt to make such a vehicle was put into action, being the Panzerjäger I. This vehicle was produced by Alkett through May 1940 and took the Czech derived PaK(t) and mounted it onto an open-topped citadel on the chassis of a Panzer I Ausf.B tank. The museum here has just completed a rebuild/replica of the Panzer I, which was a machine-gun armed, turreted tank, that entered service in 1934. By 1940 they were obsolete due to lack of decent armour and main gun. However, they proved to be a more than adequate donor vehicle for an effective anti-tank weapon. The resulting Panzerjäger I remained in service up to 1943. It established the concept that a mobile anti-tank vehicle could be developed that while lightly armoured, could carry a heavier gun than a tank of comparable size and weight could mount. This was by virtue of the fact that the tank heavier armoured turret could be replaced with a lighter fixed citadel or casemate. Around 200 of these simple Panzerjäger I were produced, setting the type for future armoured and mobile anti-tank vehicles. As the war progress, many similar projects such as these took shape, including repurposing captured guns and/or chassis for employment as anti-tank weapons. The German StuG III Assault Gun was itself migrated into this role with the mounting an anti-tank gun from March 1942, adding the StuK 40 L/43 gun. At that point these vehicles started being deployed into armoured units, such as Panzer Grenadier and Panzer Division, to equipe mobile anti-tank elements. With the development of heavier tanks such as the Panzer V Panther that mounted even more potent anti-tank guns, ways of using older chassis to repurpose these weapons as tank killers progressed. Experience gained on the Eastern Front in September 1942 called for a new standard for these type of vehicles. 100mm of armor to the front, 40–50mm on the sides, wider tracks, top speed of 26km/h and the lowest possible profile. When a castmate style anti-tank vehicle was need to mount the lethal Pak 42 L/70 of the Panther, the Panzer IV/70 you see here was conceived. The Panzer IV/70(V) used a modified Panzer IV Ausf.H chassis, however the upper hull was redesigned to utilise sloped armour plates, being 80mm, at the front, and the internal layout was significantly altered. This gave much better protection to the tank than 100mm of vertical armour would afford. A new heavy mantlet and internal gun mount were designed permitting 15° traverse to the right and 12° to the left. The running gear was borrowed directly from the Panzer IV. Despite having the architecture settled, availability of the most critical element, the gun of the Panther tank, proved to be a problem. For this reason, production started in late 1943 using the less capable 7.5 cm PaK 39 L/48, and these vehicles were termed the Jagdpanzer IV. In late 1944 production using the PaK 42 L/70 commenced, at which point the vehicle became known as the Panzer IV/70. The vehicle was built from late 1943 until the end of the war by Vomag. About 750 Jagdpanzer IV with the less capable 7.5 cm Pak 39 were built to November 1944. About 930 units of the Panzer IV/70(V) with the PaK 42 were made between August 1944 and April 1945 by Vomag. Production was also undertaken by Nibelungenwerk in Austria who placed the casemate and gun directly onto a Panzer IV chassis. These were termed the Panzer IV/70(A) and 277 were built. The PaK 42 was made by Rheinmatall could penetrate 112mm of angled armour at 1,000m range using the standard Panzergranate 39 Armour Piercing ammunition, or 149mm of armour if using the Panzergranate 40 APCR shell. The vehicles had the Maybach HL-120 TRM petrol engine. This is a 12L, V12 dry sump engine developing 221kW, mounted in the rear of the vehicle. Power to the front drive sprockets is via a drive shaft running forward under the crew compartment to the transmission and final drive at the front. This moved the vehicle at a maximum speed of 35kph. Chassis is 8 road wheels per side, arranged in 4 bogies with leaf spring suspension. There were four return rollers, reduced to three after December 1944. It used 40cm wide tracks. Panzer IV/70(V) began to reach frontline units at the end of 1944 and saw action in the Ardennes offensive in the West and and in North Poland and around Budapest in the East. Only limited numbers were used in Italy.