Cutaway - Pz.IV

In the last model of the Pz. IV, the Ausf. J, the hand crank became almost paramount when the auxiliary engine/generator and power traverse were removed from the tank. To help compensate, the gunner was then supplied with a new manual gearing system to ease the work, but it still took a lot of muscle to rotate the turret with its long gun. Although the coax MG was normally aligned with the main gun and gunner's sights, it could also be elevated independently, and the vision flap on the right side of the mantlet that we saw in an earlier sketch continues to allow the weapon to be visually sighted by the loader. In later vehicles (beginning with the Ausf. F2) this whole system was deemed unnecessary and wouldn't have worked anyway with the revised L/43 gun mount, so the coax MG was fixed in its mount and the small vision flap to the right of the mantlet was finally eliminated.

The Army's Technical Regulations Leaflet 1944 No 256 speaks of the introduction of an "Eastern Front Track" (German: Ostkette) for the Pz Kw IV which increased the overall width to 320.6 cm. In March 1944 the final version of the Pz Kw IV appeared, the Model J. Army Technical Regulations Leaflet 1944 No 184 of 3rd March 1944 states that the electric turret-traversing gear was discarded in this "J" version, and an auxiliary fuel container of 200 litres capacity was built into the engine compartment. The total fuel load was now about 680 litres. At the same time the hand traversing mechanism had to be fitted with a second reduction gear to permit the turret to be turned when the vehicle was travelling on an incline. Some armoured aprons fitted to the sides of this version, consisted of a strong wire netting in place of the usual sheet steel. Rheinmetall-Borsig of Unterliiss were made responsible for the production of the 7.5 cm KwK 40 L/48 which armed the Model H. The vehicles were produced practically until the end of the war in 1945.

Sturmgeschütz IV Final Production

Sturmgeschütz IV (7.5cm StuK40 L/48) (SdKfz 167) was an armored vehicle (assault gun, AFV or armoured fighting vehicle) in combat use during the Second World War (World War II or WWII) in the European theater. The Sturmgeschütz IV was a fully tracked all-terrain vehicle designed for military operations. Sturmgeschütz IV, abbreviated as the StuG. IV, was produced and deployed by the German Army (Heers) of Nazi Germany (the Third Reich). The technical drawing (plan, layout or profile) shows the general appearance characteristics of the specified model (version) of the Sturmgeschütz IV tank for purposes of identification and reference.

Sturmgeschütz IV Main Production

In November 1943, Alkett, the manufacturer of the StuG III, suffered damage in a bombing raid. Alkett produced 255 StuG III in October 1943, but in December production fell to just 24 vehicles. A conference held December 6–7, 1943, addressed possible solutions to this problem. Hitler welcomed the suggestion of taking the StuG III superstructure and mounting it on a Panzer IV chassis. The StuG IV could be more quickly manufactured than the Jagdpanzer IV at the time. This restarted the Sturmgeschütz IV project. This time, the superstructure of the StuG III Ausf. G was mounted on a Panzer IV chassis 7, with a box compartment for the driver added. Combat weight was 23000 kg, lighter than the 23900 kg for the StuG III Ausf. G. On Dec. 16-17, 1943, Hitler was shown the StuG IV and approved it. To make up for the large deficit in StuG III production StuG IV production was now given full support.

From December 1943 to May 1945, Krupp built 1,108 StuG IVs and converted an additional 31 from battle-damaged Panzer IV hulls. While the number is smaller than the 10,000+ StuG III, the StuG IV supplemented and fought along with StuG III during 1944-45, when they were most needed.

Sturmgeschütz IV First Production

The Pz.Kpfw.IV was also converted to an assault gun (Sd.Kfz.167) after a bombing raid severely damaged the ALKETT plant producing the StuG III. The turret and superstructure from the Pz.Kpfw.IV was replaced by a modified StuG III Ausf.G superstructure. Since the Pz.Kpfw.IV hull was longer than that of the Pz.Kpfw.III, it was necessary to create a new driver's position by extending the left side of the superstructure front forward. This new driver's position was topped by a pair of periscopes and an access hatch. The cast gun mantlet was introduced in February 1944. Later production vehicles were also fitted with the naehverteidigunswaffe close-in defense weapon, and starting in December 1944 some StuG IV were only fitted with three track return rollers per side. Other modifications to the Pz.Kpfw.IV and StuG III Ausf.G were also grafted onto StuG IV, like the Pz.Kpfw.IV's flash suppressing mufflers and the remote-control external machine gun mount.

Sturmpanzer IV Series 1

Production of the first series of 60 vehicles began in April 1943. Fifty-two of these were built using new Panzer IV Ausf. G chassis and the remaining 8 from rebuilt Ausf. E and F chassis. Survivors, about half, were rebuilt beginning in December 1943; they were mostly rebuilt to 2nd series standards.

Sturmpanzer IV Series 2

Production restarted in December 1943 of another 60 vehicles, using only new Ausf. H chassis, and continued until March 1944. The Sturmpanzer's baptism in combat at the Battle of Kursk proved that the driver's compartment was too lightly armored and it was reinforced. The gunner's hatch was removed and a ventilator fan was fitted, much to the relief of the crew. Internally sprung, steel-rimmed road wheels replaced the front two rubber-rimmed road wheels in an effort to reduce the stress on the forward suspension that was only partially successful.

Sturmpanzer IV Series 3

Production of the 3rd series ran from March to June 1944 with few changes from the second series. The Fahrersehklappe 80 was replaced by periscopes and the lighter StuH 43/1 was used.

Sturmpanzer IV Series 4

The superstructure was redesigned in early 1944 for the fourth series, which used the chassis and HL120TRM112 engine of the Ausf. J, and was in production between June 1944 and March 1945. It featured a redesigned gun collar, as well as a general reduction in height of the superstructure. This redesign also introduced a ball mount in the front superstructure for a MG 34 machine gun with 600 rounds. The vehicle commander's position was modified to use the cupola of the Sturmgeschütz III Ausf. G, which could mount a machine gun for anti-aircraft defense.

Panzer.IV by Italeri

 
STURMPANZER IV BRUMMBAR SD.KFZ.166
The Sturmpanzer Brummbar was based on a variation of the hull of the Panzer IV armoured tank and devised for the infantry to reduce need for bunkers and fortified resistance centres. This vehicle was fitted with a heavy 15 cm howitzer with shortened mine-launching barrel, fully capable of completing its task. 306 models were built from early 1943 when the vehicle was first introduced.

Panzer IV Ausf H

Designed as support tank, the Panzer IV was not originally intended to engage enemy armor. However, with the flaws of pre-war design becoming apparent and in the face of Soviet T-34 and KV-1 tanks, the Panzer IV assumed the tank-fighting role instead of PzIII . The most widely manufactured and deployed German tank of the Second World War, the Panzer IV was the “work horse”of German tank’s regiments, used as the base for many other fighting vehicles, including tank destroyers, self-propelled artillery and self-propelled anti-aircraft guns. Robust and reliable, it saw service in all combat theaters, and has the distinction of being the only German tank to remain in continuous production throughout the war, with over 8,500 produced between 1936 and 1945. 

Upgrades and design modifications, often made in response to the appearance of new Allied tanks, extended its service life. Generally these involved increasing the Panzer IV's armor protection or upgrading its weapons. The Ausf. H version, began production in April 1943 and received the designation Sd. Kfz. 161/2. This variant saw the integrity of the glacis armor improved by manufacturing it as a single 80-millimetre plate The 75mm KwK 40 L/43 gun was replaced by the longer KwK 40 L/48 . The vehicle's side and turret were further protected by the addition of 5-millimetre side-skirts and a turret skirt. During the Ausf. H's production run its rubber-tired return rollers were replaced with cast steel. The Panzer IVH was the most widely produced variant with over 3000 tanks assembled in Nibelungenwerke and Vomag plants.

JAGDPANZER IV AUSF.F SD.KFZ.162
The JAGDPANZER IV self-propelled tank-killer was built on the chassis of the Pz.Kpw. IV, one of the most efficient and widely used German tanks of the Second World War. Characterised by a low profile, the JAGDPANZER IVs were produced in their hundreds, steadily being improved and fitted with better weaponry such as the long-barrelled 7.5 cm gun that made it a match for any Allied tank.

Pz. Kpfw. IV Ausf. F1/F2 early G

The Panzer IV was the most extensively used German tank during the Second World War. It represented the “backbone” of the German Panzer Divisions on all operational theaters. The production of Panzer IV Ausf. F, started in 1941, marked a decisive boost in the evolution of the tank. It featured an improved armor on the turret and hull. The first version of Panzer IV F,  featuring the traditional 7.5 cm. KwK 37 short-barreled cannon,  were not able to fight successfully against the Soviet T-34 and KV-1 heavy armored tank.  The adoption of the anti-tank design KwK 40 long-barreled cannon, on the Ausf. F2 version, has decisively increased the Panzer IV effectiveness against enemy tanks. Thanks to its new high velocity and high penetration gun, the Panzer IV became, once again, “lethal” on the battlefields.

Sd. Kfz. 167 Sturmgeschütz IV
Sturmgeschütz, abbreviated StuG, was the weapon of the Sturmartillerie, the branch of the German artillery tasked with close fire support of infantry. StuGs were very successful in their intended support role and destroyed, among others, many bunkers, pillboxes and other defences. The StuG is not generally considered to be a true tank because it lacks a turret. The gun was mounted directly in a casemate-style fashion, with as low a profile as was possible to reduce vehicle height, and had a limited lateral traverse. Omitting the turret made production simpler and less costly, enabling greater numbers to be built. By late 1943 improved Allied tanks and tank destroyers  with improved guns, rotating turrets, and superior mobility, forced the StuG of being primarily an ambush weapon. 

The StuGs quickly became more of a liability in terms of resource utilization than an asset (the German's had initially increased StuG production to replace standard tank losses), but they continued to be used as the German losses of all types of armored vehicles now exceeded production. Long since not used as originally intended, the Stug's increasingly proved a poor substitute for conventional tanks except in rare war’s envelope. By 1943 Germany was in a downward spiraling arms race with the Allies and the production switched from StuG.III  to StuG.IV. Using the Pz.IV’s chassis, the StuG.IV was the simple combination between Ausf.H and Ausf.J Pz.IV’s versions with StuG.III casemate, in an elongated version. From December of 1943 to March of 1945, 1139 were produced by Krupp at Magdeburg. Stug IV (Sd.Kfz.167) was armed with 75mm StuK 40L/48 gun mounted in cast version of "saukopf" mantlet. Majority was issued in armoured companies to infantry and Panzer Grenadier divisions with few exceptions.

Vorpanzer for the Pz.IV Ausf F1

Vorpanzer F1, with extra bolted appliqué armour on the sides, gun mantlet and frontal glacis, with the 5th Panzerdivision, Group Center, Russia, winter 1941-1942.

The most complete story of the Vorpanzer for the PzIV Ausf.F is in the Band 5 (Neu), Begleitwagen, Panzer IV by W.Spielberger.

Here's a summary:

Conference 7.7.41- The Führer has been informed that in the battles in North Africa that armour-piercing rounds are becoming a problem from English tanks. The Führer asks that new production Panzer be equipped w/ spaced armour in front of the main armour.

Conference 29.11.41- the Fuhrer intends for all unit to be equipped with the new Vorpanzer.

Report from Krupp-Essen, 24.12.41- There is a shortage of material for the Vorpanzer... Due to the situation delivery of the first Vorpanzer is expected on Feb 1, 1942. There is a question, should the turrets be delivered w/ the Vorpanzer or not, that hasn't been made very clear.

There is more text but is doesn't mention about shipping of the Vorpanzer to combat units. The idea was dropped with the production of the Ausf.G with the longer 7.5-cm KwK. There is a photo of 2 PzIV with Vorpanzer, and the first has the name "Hansi" painted on it. There is no other markings to distinguish which unit it is. But by the overall look of the rest of the vehicles it looks like that it is a PzAusbAbt.