WW2 German Assault Guns

Beute Sturmgeschütze mit 7.5 cm KwK L/18 850(i)

German Reich (1943-1945)
Self-Propelled Assault Gun – 123 Captured and 55 Built

After the Armistice the Regno d’Italia (English: Kingdom of Italy) had signed with the Allied forces on 8th September 1943 was made public, what was left of the Italian war industry and armament of the Regio Esercito (English: Royal Army) were taken over by the Germans. In terms of armored vehicles, most were obsolete designs that were put to use only as nothing else was available. The Semoventi (English: Self-Propelled Guns), on the other hand, were of more use, and some 123 Semoventi M41 da 75/18 and Semoventi M42 da 75/18 (English: 75 mm L/18 Self-Propelled Guns on M41 and M42 chassis) were captured. The Germans renamed the captured vehicles Beute Sturmgeschütz mit 7.5 cm Kampfwagenkanone L/18 850 (italienisch) (English: Captured Assault Gun with 7.5 cm Tank Cannon Coded 850 [italian]). These were mainly used in Italy, while a few saw service in the Balkans, Hungary, and in Germany as the Second World War drew to a close.

A captured Sturmgeschütz M42 mit 75/18 850(i) of 2 Kompanie, Panzerjäger Abteilung 278 in Ancona, Italy, 17 July 1944. Source:

The Italian Semoventi da 75/18

The Semoventi da 75/18 (English: 75 mm L/18 Self-Propelled Guns) were a series of Italian self-propelled guns based on the Serie M (English: M Series) medium tanks. Production started with the Semovente M40 da 75/18 (English: 75 mm L/18 M40 Self-Propelled Gun), which was built using the chassis of the Carro Armato M13/40 (English: M13/40 Tank). The second model was the Semovente M41 da 75/18, based on the chassis of the Carro Armato M14/41. The two models differed only by a different diesel engine. The third and last model was the Semovente M42 da 75/18, based on the chassis of the Carro Armato M15/42. This model differed from the previous two semoventi da 75/18 by its new engine compartment fitted with a powerful petrol engine.

One of the first produced Semovente M40 da 75/18. Source: Nicola Pignato
A Semovente M41 da 75/18 abandoned by the Italian soldiers in North Africa. Source:

From late April 1941, 60 Semovente M40 da 75/18 were built, before the superior-engined Semovente M41 da 75/18, of which 162 were produced until November 1942, substituted them on the assembly line. The first Semovente M42 da 75/18 was finished on 21st November 1942, even though the self-propelled gun was officially adopted on 9th December 1942. In total, by the end of July 1943, 190 Semoventi M42 da 75/18 were produced. An unknown number of other M42s were produced between 1st August and 8th September 1943.

A Semovente M42 da 75/18 ready to be delivered to the Italian Army before the Armistice. Source:

The Semovente M40 da 75/18 was powered by a V-shaped, 8-cylinder, liquid-cooled FIAT-SPA 8T Modello 1940 diesel engine with a maximum power output of 125 hp at 1,800 rpm, giving the vehicle a maximum speed of 31.8 km/h.
It was not a very reliable engine. In fact, it was developed for 8-tonne vehicles, while the Semovente M40 da 75/18 weighed 13.1 tonnes. The Obice da 75/18 Modello 1934 (English: 75 mm L/18 Howitzer Model 1934) was located in the front of the vehicle, slightly to the right, in a ball mount support that allowed a notable 36° of the traverse, 20° on the left and 16° on the right, and an elevation from -12° to +22°. Anti-aircraft defense was ensured by a Fucile Mitragliatore Breda Modello 1930 (English: Light Machine Gun Breda Model 1930) mounted on the vehicle’s roof, with a reserve of 600 rounds on board.

The Obice da 75/18 Modello 1934 mounted on a Semovente da 75/18 that is ready to be delivered. Source:

The Semovente M41 da 75/18 was powered by the powerful FIAT-SPA 15T Modello 1941 8-cylinder V-shaped diesel engine, producing 145 hp at 1,900 rpm, increasing the maximum speed to 33.3 km/h. The anti-aircraft machine gun was substituted by a powerful Mitragliatrice Media Breda Modello 1938 (English: Medium Machine Gun Breda Model 1938) with 1,104 rounds on board.

The Semovente M42 da 75/18 was powered by the petrol version of the FIAT-SPA 15T Modello 1941, the new FIAT-SPA 15TB (‘B’ for ‘Benzina’ – Petrol) Modello 1942 petrol 12-cylinder V-shaped water-cooled engine that produced 190 hp at 2,400 rpm. In order to accommodate the new petrol engine, increased fuel tanks and new fire extinguisher system, the chassis of the vehicle was lengthened from 4.92 m to 5.06 m. Apart from these modifications, the M42 was identical in structure and armament to the M41.

The armor of the Semoventi da 75/18 was 30 mm thick on the transmission cover plate, which was rounded. The upper armored plate that covered the transmission was 25 mm thick and angled at 80°. The superstructure had a 50 mm thick front plate angled at 5°. The Semovente M41 and M42 da 75/18, was composed of two 25 mm armored plates bolted together to increase protection. The angled plate that connected the upper glacis plate of the transmission cover and the front plate was 30 mm at 65°.

The sides were 25 mm for the hull and casemate, with the only difference being that the casemate’s sides, which were angled at 8°. The rear casemate was protected by a 25 mm thick armored plate. The rear of the engine compartment was 25 mm thick and angled at 20°. The roof was 15 mm thin, horizontal in the first section and then angled at 85°. On the sides of the roof, other 15 mm plates were angled at 65° on the right and to 70° on the left side.

The engine compartment roof was 10 mm and angled at 74°. The inspection hatches of the engine compartment had the same thickness. The brake inspection hatches were 25 mm thick, while the driver port on the front armored plate was 50 mm thick.

After the Armistice

In September 1943, due to the Allied invasion of Sicily and internal pressure, Italy sought to negotiate peace with the Western Allied powers. The Germans were expecting this and planned to occupy as much of Italy as possible. With the occupation of most of Italy, the Germans came into possession of a number of armored vehicles, but also weapon-producing facilities, along with many vehicles that were awaiting assembly for their former ally.

A Semovente M42 da 75/18 inspected by some civilians in Parma. It was abandoned intact by Italian soldiers of CCCCXXXIII Battaglione Complementi Carri M during the fighting with the Germans in the days after the Armistice. Source:

On 1st October 1943, the Germans declared to have captured a total of 123 Semoventi M41 and M42 da 75/18. The number did not account for the Semovente M40 da 75/18 because all the 60 vehicles delivered to the Regio Esercito in 1941 were lost in North Africa. The Germans renamed the Semovente M41 da 75/18 as the Beute Sturmgeschütz M41 mit 7.5 cm KwK L/18 850(i) (which stands for Italienisch (English: Italian)), while the Semovente M42 da 75/18 was renamed Beute Sturmgeschütz M42 mit 7.5 cm KwK L/18 850(i). German sources also referred to them as StuG M41 mit 75/18 850(i) or StuG M42 mit 75/18 850(i) as abbreviations. Sometimes, German official documents did not mention the chassis model. For the sake of simplicity, this article will refer to them simply as StuG M41 or StuG M42.

Evaluation by the Germans

After the Armistice, the Generalinspekteur der Panzertruppen (English: Inspector General of the Armed Forces) of the German Army began analyzing the vehicles produced in the various Italian factories. The Inspectorate considered the StuG M42 as an underpowered vehicle, but there were enough parts available for an additional 55 vehicles. The production of the better-armed semoventi, such as the Beute Sturmgeschütz M42 mit 75/34 851(i) (German for the Semovente M42M da 75/34) and the Beute Sturmgeschütz M43 mit 105/25 853(i) (German for the Semovente M43 da 105/25) continued at a slow pace. The final report of the Generalinspekteur der Panzertruppen about the Italian Beute Sturmgeschütz was that they had a low profile and low weight, but cramped fighting compartments, limited visibility, and thin frontal armor, all of which were unsatisfactory.

German Production

After the assignment of the Oberkommando der Wehrmacht or OKW (English: Upper Command of the Armed Forces) and Heereswaffenamt Italien (English: Army Weapons Agency of Italy), the Generalinspekteur der Panzertruppen took over previous Regio Esercito contracts since components were available. The German order of 5th October 1943 was for 55 Beute Sturmgeschütz M42 mit 75/18 850(i), 80 Beute Sturmgeschütz M42 mit 75/34 851(i), and 60 Beute Sturmgeschütz M43 mit 105/25 853(i).

On 5th October 1943, contracts were signed between Ansaldo and the Germans for the delivery of new Italian self-propelled guns with some modifications. The German modifications concerned the addition of 4 bigger teeth on the sprocket wheel. These were intended to prevent the track from slipping from the wheels while driving in muddy or snowy terrain. Another modification requested by the Germans was to substitute the right roof hatch with one openable in two parts for better ventilation of the fighting compartment. Some Stahlhelm supports for the crewmembers were also added on some vehicles on the roof.

At the end of 1943, the German Generalinspekteur der Panzertruppen had planned to equip the German divisions with some 143 medium tanks of the Serie M, 83 StuG M42 mit 75/18, and 109 StuG M42M mit 75/34. This meant that they needed to order Italian companies to produce 28 medium tanks of the Serie M, 82 StuG M42 mit 75/18, and a total of 200 StuG M42M mit 75/34 (including reserves). Of these new armored vehicles ordered, the Germans planned to put 32 tanks of the Serie M, 130 StuG M42 mit 75/18, and 119 StuG M42M mit 75/34 in reserve, while the others would be delivered to first line units or to training schools.

The Germans implemented some minor changes to the StuG M42s, such as adding four larger teeth on the front drive sprocket to prevent the tracks from slipping off. Source:

After the Armistice, the Germans planned to produce a new vehicle, the Beute Sturmgeschütz M43 mit 75/46 852(i), aka the Semovente M43 da 75/46, armed with a Cannone da 75/46 Contraerei Modello 1934 (English: 75 mm L/46 Anti-Aircraft Cannon Model 1934).

In 1944, the Germans produced the Beute Sturmgeschütz M43 mit 75/46 852(i) and adopted the powerful Cannone da 75/46 Contraerei Modello 1934 as a tank gun, named by the Germans as Kampfwagenkanone 75/46 (English: 75 mm L/46 Tank Cannon). The Germans hoped to equip all Italian self-propelled guns in production with this powerful gun. This meant that all the Beute Sturmgeschütz M42 mit 7.5 cm KwK L/18 850(i) had to be modified, but it seems that this project would never be started because the production rate of the Kampfwagenkanone 75/46 was one or two guns per month.

Beute-Sturmgeschütz M42 mit 7.5 cm KwK L/18 850(i) captured by a Canadian unit and redeployed by Canadian soldiers against their former owners in Italy. It was nicknamed ‘Zombie’. Source:

Another German plan was to modify the Kampfwagenkanone 75/46 breech to fire the same ammunition as the 7,5 cm Panzerabwehrkanone 40 or PaK 40 anti-tank cannon, in Italy known under the designation Cannone da 75/43 Modello 1940 (English: 75 mm L/43 Cannon Model 1940). It is not clear if the Germans reached the goal of modifying the Italian guns to fire German ammunition, but the modifications would have forced a slow process to modify the guns, maybe explaining why there was an average production of 1.5 guns per month.

The Germans also briefly played with the idea of mounting the 7,5 cm Panzerabwehrkanone 40 on the M43 self-propelled gun’s chassis to ease the gun production, but, by the end of the war, nothing was decided.

In the late war, the German Army wanted to save on raw materials, producing only the most powerful and reliable vehicles. This was done in Germany and also in Italy. It was planned to cancel the production of all the Italian vehicles apart from the Beute Sturmgeschütz M43 mit 75/46 852(i), the Beute Panzerspähwagen AB43 203(i), and the Panzerkampfwagen P40 737(i). On 20th February 1945, the German Army planned to equip 4 infantry divisions with such vehicles.

The Aufstellungsstab Sued was in favor of a production contract extension with the Italian factories. They essentially wanted to have all the Italian armored vehicle factories still capable of producing vehicles convert their production lines to the Beute Sturmgeschütz M43 mit 75/46 852(i) and the Beute Panzerspähwagen AB43 203(i) (no mention of the Beute Panzerkampfwagen P40 737(i)), with a production estimated on 50 StuGs and 50 Pz.Sp.Wg. per month. The new production schedule for the Ansaldo-Fossati plant of Sestri Ponente, near Genoa, where all the semoventi were produced, was of 116 Semoventi M43, 51 Carri Armati P26/40, and 22 command tanks to be produced by August 1945. Due to Allied bombings of the Italian factories that produced semoventi and other armored vehicles, the production rate was slower. In early 1945, the Germans moved part of the production and assembly of armored vehicles from Genoa and Turin to Milan and Novara.

German Organization

At the same time as the capitulation of its former ally, Italy, the German Army undertook structural changes in order to increase the number of panzer divisions. Over a dozen new panzer grenadier divisions and a few more SS formations were to be formed. This, in turn, required an increased number of tanks, which the German industry was incapable of producing. To overcome this, panzer divisions were to receive an anti-tank battalion armed with 45 StuG IIIs. Not surprisingly, even this was impossible to achieve. Luckily for the Germans, the captured Italian equipment became available. As the Italian command did, the German forces assigned the semoventi to former artillerymen (obviously trained to man self-propelled guns) and not to tank crews.

The long gun-armed StuG III was one of the most effective German anti-tank vehicles, but also the most produced. Despite this, there were never enough of them to satisfy the war demands of the German Army. Source: Panzernet
To supplement the lack of StuG IIIs, Italian Semoventi vehicles were reused for this purpose. Source:

Already on 20th September 1943, the German High Command ordered the delivery to infanterie-divisionen (English: infantry divisions) of: 11 Carri Armati M15/42, 3 command tanks, and 80 Semoventi M42 da 75/18 and M42M da 75/34. At the end of September 1943, another 6 Carri Armati M15/42, 4 Command Tanks on M42 chassis, 6 Semoventi M42 da 75/18, 5 Semoventi M42M da 75/34, and 14 Semoventi M43 da 105/35 were delivered to German infantry divisions.

From the stockpiles of captured StuG M41/42s, together with other Italian vehicles, the Germans re-equipped some units, such as the 90. Panzergrenadier-Division (English: 90th Mechanized Division). Others were allocated to various infantry divisions, such as the 44. Infanterie-Division, 65. Infanterie-Division, 71. Infanterie-Division, 305. Infanterie-Division, and 334. Infanterie-Division. These numbers would be expanded in 1944. Note that these units also received the improved semoventi vehicle, which is not always specified in the sources. While this helped rearm the units, in reality, it also caused huge logistical problems. For example, the 90. Panzergrenadier-Division had in its inventory Panzer IVs, StuG IIIs, and Italian StuG M41/42s.

In late 1943 to early 1944, the Germans started to train some new tank crewmembers on Italian armored vehicles, with some training schools in northern Italy. These units trained with former Regio Esercito vehicles but were mainly equipped with post-Armistice production self-propelled guns and tanks.

The 26. Panzer-Division (English: 26th Armored Division) was equipped with Italian tanks and self-propelled guns. Even the Fallschirm-Panzer-Division 1. “Hermann Göring” (English: 1st Paratrooper Tank Division) of the Luftwaffe (English: Air Force) was equipped with Italian captured tanks and SPGs.

In 1944, Sturmgeschütz-Abteilung 210. and Sturmgeschütz-Abteilung 914. of the Luftwaffe, which were equipped with Italian tanks and semoventi, were brought to brigade level, even if, in practice, only a few new Italian vehicles were assigned to them. Each of the 2 Sturmgeschütz-Abteilungen had 3 batteries with 14 semoventi and a command battery with 2 Italian command tanks.

An Italian Semovente M42 da 75/18 in German service during maintenance in a German unit field workshop. The FIAT-SPA 15TB Modello 1942 petrol engine is in the foreground, while, behind the semovente, there is a Jagdpanzer IV. Source: eshop

In 1944, for the German infantry divisions created in Italy, Panzerjäger-Abteilungen were created. These armored battalions would be equipped with 3 companies, even if, due to the low number of vehicles, some were equipped with only 2 companies. One company was usually equipped with 6 StuG M41 or StuG M42, 8 StuG M42M mit 75/34, and one command vehicle. Later, the majority of the companies also received 4 StuG M43 mit 105/25 and another command tank. Of course, depending on the combat situation, availability, or logistical transportation, these numbers were different between units. The M41/42 would see some service in Italy, but their general use was hampered with mechanical and logistical problems.

In May 1944, a German report claimed that there were 85 Italian StuGs in service in German hands on the Italian peninsula, of which 29 were deployed against the Allies in Anzio and Nettuno. In July 1944, another 28 Italian StuGs were delivered to German divisions to replace part of the losses suffered on the Gustav Line.

German Service

German Service in Italy

Beute-Sturmgeschütz mit 7.5 cm KwK L/18 850(i) abandoned during the battles for the Gustav Line. Note that, on top of the 3-tone camouflage painted in the factory before the Armistice of 1943, the coat of arms of the 71. Infanterie-Division was painted on the left and that of the Panzerjäger-Abteilung .171 on the right. Above the coats of arms, the registration plate of the Regio Esercito was covered with a layer of gray paint. On the fender, a German-made jack is visible and, on the right side of the superstructure, is the name of the vehicle, ‘Margarete 3’. Source:

71. Infanterie Division

In January 1944, the 71. Infanterie Division (English: 71st Infantry Division) was deployed in the Montecassino area to fight the Allied forces. Together with the infantry and artillery regiments, the division had in its ranks the Panzerjäger-Abteilung .171 (English: 171st Tank Destroyer Battalion) equipped with Beute Sturmgeschütz M42 mit 75/18 850(i), Beute Sturmgeschütz M42 mit 75/34 851(i), and German vehicles.

The division fought in the Monte Cassino area until May 1944 and then retreated after a Free French Forces offensive, maintaining new defensive positions until September 1944.

Free French troops advancing somewhere in Italy in August 1944. On the roadside, near a hospital, lay abandoned and parked some vehicles that participated in the previous day’s battle. The StuG M42 mit 75/18 850(i) belonged to Panzerjäger-Abteilung .171. Original color photo Source: LIFE magazine

65. Infanterie Division

The 65. Infanterie Division was in La Spezia when the order to disarm the Italian soldiers was received on 9th September 1943. They quickly reached Genoa and Sestri Ponente, where the semoventi were produced, and captured a great number of not yet delivered Italian vehicles.

In October 1943, the 65. Infanterie Division, with its Panzerjäger Abteilung 165. with Italian StuGs, was moved to Ortona and then to Orsogna, where it maintained positions after fierce fighting with the 8th Indian Division and 2nd New Zealand Division. During the fighting, the armored vehicles losses were limited compared to the infantry’s ones. The division then fought in Anzio and Firenze, losing all its armored vehicles.

Between late August to early November 1944, in fighting on the Gothic Line, the Germans lost a total of 62 StuG mit 75/18, 43 StuG M42M mit 75/34, 35 StuG M43 mit 105/25, and 5 command tanks. At the end of 1944, there were some 92 75 mm-armed Semoventi in German service.

278. Infanterie Division

Beginning in May 1944, the Panzerjäger-Abteilung .278 deployed their Stug M42s in Ancona, where it fought fiercely against the 2nd Polish Army Corps that entered Ancona on 18th July 1944. After that, it lost all the Italian vehicles in the Gothic Line.

Another image of captured Sturmgeschütz M42 mit 75/18 850(i) number 232 of 2 Kompanie, Panzerjäger Abteilung .278 in Ancona, Italy, 17th July 1944. Source:

German Assessment of the Beute Sturmgeschütz mit 7.5 cm KwK L/18 850(i) in Italy

The general performance of the StuG M41/42 seems to have been rather poor based on reports of some units that operated them in Italy. For example, the 278. Infanterie-Division, which had Beute Sturmgeschütz M42 mit 75/18 850(i) and Beute Sturmgeschütz M42 mit 75/34 851(i), reported that these had little combat value, to the point of being completely useless.

Another StuG M42 mit 75/18, number 201, which belonged to the Panzerjäger Abteilung 278, captured by the Allies in Forlì, Italy at the start of 1945. Source: Wiki

Similar complaints were made by the 29. Panzergrenadier-Division, which noted problems with the automotive components. This unit especially emphasized that Italian self-propelled guns were not a proper replacement for the StuG IIIs. The 356. Infanterie-Division reported that only the 105 mm-armed Beute Sturmgeschütz M43 mit 105/25 853(i) could be used in an anti-tank role, while short barreled 7.5 cm-armed semoventi could not. These were instead used as mobile artillery. The Panzerjäger-Abteilung .356 of the 356. Infanterie-Division was also the unit that came up with the idea of improving the armor of Italian self-propelled guns.

A StuG M42 in German service destroyed in Roccasecca, 100 km south of Rome. Source:

The German frontline combat units appreciated the Semoventi’s lightweight and small dimensions. The Italian self-propelled guns were easy to transport on a railway or towed by trailers. In many cases, the German troops that deployed them against the Allied forces on the Italian peninsula preferred the Italian self-propelled guns to ambush or fight the Allies troops in urban fighting. In fact, due to their limited weight, they could be easily deployed on mountainous terrain, where Allied and German medium tanks had difficulty climbing, or on city streets.

German Service in Yugoslavia

While the majority of StuG M41/42s would see action in Italy, some would find their way to occupied Yugoslavia. There, the Axis forces were battling an ever-growing Partisan movement. The number of Yugoslav Partisans and equipment began to rise, especially in 1944, thanks to support provided mostly by the Western Allies and, later, the Soviet Union. Germany, due to a lack of anything better, mostly used captured armored vehicles in Yugoslavia. After 1943, most older French tanks were replaced with Italian equipment, including the Beute Sturmgeschütz M41 or M42 mit 7.5 cm KwK L/18 850(i), but also more numerous smaller Beute Sturmgeschütz L6 47/32 630(i) (German for the Semoventi L40 da 47/32) cousins armed with the 47 mm gun. Sources often do not make a differentiation between them, so identifying precise versions is not always possible.

In Yugoslavia, the Panzer-Abteilung 202 (English: 202nd Tank Battalion) is known to have used StuG M41/42 vehicles. In April 1944, this unit was to be supplied with two StuG M41/42s and other Italian equipment. As these were not available, it had to be postponed. It was not until April 1945 that this unit received 2 StuG M41 vehicles. During their retreat from Yugoslavia in May 1945, some of the equipment, including the StuG M41/42s, was captured by the Partisans.

Abandoned German equipment, including a StuG M41 and a M15/42 in May 1945. More vehicles, possibly M-tanks, can be seen in the background Source:

The Skanderbeg Panzer-Abteilung (English: Skanderbeg Tank Battalion) received a new contingent of Italian captured equipment in August 1944, including 2 StuG M41s. These were noted to be in poor mechanical condition, possibly even beyond repair. Their use, if at all, was thus likely limited.

The German-operated StuG M41/42s saw combat use during the battle for the Yugoslavian capital Belgrade, which lasted from 15th September to 24th November 1944. The Germans were hard-pressed by the Soviets, who agreed to help the Partisans during this fight. Ultimately, they were driven out, and the city was liberated. In the process, the Germans lost at least one StuG M41/42.

This vehicle was abandoned by the Germans in Belgrade, 1944. Source:
The same StuG M41 mit 75/18 abandoned in Belgrade deployed by the Partisans, probably for a post-battle propaganda image. Source:

In Yugoslav Partisan Hands

The Yugoslav Partisans managed to capture some StuG M41/42s from the Germans during 1944/45. At least one such vehicle was used by a tank crew training school that the Partisans opened in freed Serbia in late 1944. A few more were captured during the liberation of Belgrade and some in the final days of the war. While these survived the war, given their obsolescence and lack of spare parts, their use was limited. Their fate in Yugoslavian service post-war is unclear, but they were likely scrapped at some point, as none of them survived until today.

This vehicle from the 202nd Tank Battalion was captured by the Partisans in Slovenia in May 1945. The added spare track links were a rather common sight among the Italian tanks operated by the Germans in Yugoslavia. Source: Wiki


The StuG M41/42 vehicles saw extensive use with the Germans compared to other captured vehicles. However, the Italian vehicles’ service was affected by a lack of spare parts and ammunition. Their overall numbers were also rather small, as the production of new vehicles was limited. Thus, employing them on a large scale, such as had been the case with the Panzer 38(t) (and the later versions based on its chassis), was not possible. Given the rather obsolete pool of Italian weapons, the Semoventi were the best available vehicles that the Germans could reuse.

Beute Sturmgeschütz M41 mit 7.5 cm KwK L/18 850(i), M42. Illustrations by the illustrious Godzilla funded by our Patreon Campaign.
Beute Sturmgeschütz M41 mit 7.5 cm KwK L/18 850(i), M42. Illustrations by the illustrious Godzilla funded by our Patreon Campaign.

Beute Sturmgeschütz M41 mit 7.5 cm KwK L/18 850(i) Technical Specification

Crew 3 (commander/gunner, loader, and driver)
Weight 13.3 tonnes
Dimensions Length 4.915 m, Width 2.200 m, Height 1.850 m
Engine FIAT-SPA 15T Modello 1941 diesel, 11,980 cm³ producing 145 hp at 1,900 rpm.
Speed 33 km/h, 15 km/h (cross-country)
Range 200 km
Primary Armament Obice da 75/18 Modello 1934 and a Mitragliatrice Media Breda Modello 1938
Elevation -12° to +22°
Armor from 6 mm to 50 mm


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Has Own Video WW2 German Assault Guns

Sturminfanteriegeschütz 33

German Reich (1942)
Infantry Assault Gun – 24 Converted

The concept of mounting a heavy infantry gun on a tank chassis was born out of a need to provide effective destructive firepower against enemy-fortified positions. While during World War Two the Germans already used the well-known StuG III series that fit this role effectively, something with an even greater punch was desirable. The need for a well-protected vehicle armed with a 15 cm gun arose in late 1942. At that time, the Germans were bogged down attempting to take the city of Stalingrad. Due to the urgent demand for such a weapon system, a small series of improvised vehicles armed with a 15 cm gun placed inside an armored superstructure would be created on a StuG III chassis, creating the Sturminfanteriegeschütz 33.

The Sturminfanteriegeschütz 33. Colorization by Johannes Dorn. Source: Digital Collection of Armin Freitag

Early Attempts to Provide Close Fire Support Vehicles

Based on experience gained during the First World War, some people within the German Army, such as Erich von Manstein, argued for the introduction of well-armed and protected assault guns. Eventually, these would be the Sturmgeschütze (or StuG IIIs for short). These were to act as highly mobile artillery vehicles that were intended to provide close-up infantry support by destroying enemy fortified positions.

Whilst the concept was initially opposed by some elements within the German Army, the project was greenlit when it was approved by Oberbefehlshaber des Heeres (English: German Commander in Chief of the Army) Generaloberst von Fritsch in 1935. Due to many factors, but mostly related to the rather undeveloped state of the German industry and bureaucratic problems, the start of the StuG III’s production was delayed for years. The first production vehicles reached the troops at the start of the Western campaign in May 1940. Despite the small number of vehicles used, they quickly showed that a mobile, protected, and well-armed assault gun was capable of providing adequate infantry support.

The early StuG III vehicles were armed with short 7.5 cm guns, protected by 50 mm of frontal armor, and had a well-designed chassis. Despite never being produced in sufficient numbers, they performed excellently in their support role. Later, when equipped with long guns, they even became effective anti-tank vehicles, although their primary role remained to support the German infantry formations. Source: Walter J. Spielberger Sturmgeschütz and its Variants

Over the following years, the number of StuG IIIs would constantly increase. While its short barrel 7.5 cm gun was effective in its original role, due to urgent demand for mobile anti-tank vehicles, the StuG IIIs would be rearmed with long guns. After 1942, to further increase the effectiveness against enemy-fortified positions, the 7.5 cm guns were replaced by larger 10.5 cm guns.

While the StuG IIIs were well suited to their designated infantry support roles, there were never enough of them. As a result, the main artillery firepower for infantry formations came in the form of two different types of towed support guns: the lightweight 7.5 cm leIG 18 and the much heavier, larger caliber 15 cm sIG 33. Both of these proved to be excellent designs, serving the German infantry up to the end of the war. In the case of the larger 15 cm sIG 33 gun, it had sufficient firepower to destroy all but the most fortified enemy positions. It only needed a few rounds to completely demolish smaller buildings with ease. While the 15 cm sIG 33 offered great firepower to the German infantry, its weight severely limited its mobility. Infantry units of the German Army were in general not very mobile formations given the general lack of towing vehicles, mostly relying on horses to pull their equipment. Despite this, moving a heavy gun was tiresome and took some time to set up properly. Moreover, during retreats, the guns were often abandoned, as they could not be moved fast enough. These shortcomings became obvious after the Polish campaign in 1939. Shortly after that, WaPrüf 6 (English: German Army’s design office for armored vehicles and motorized equipment) issued orders to develop a self-propelled version armed with such a gun. Although initially it was intended to build a completely new design, this idea had to be abandoned due to a lack of production capacity.

The 15 cm sIG 33. Even though it was an effective, robust, and cheap gun, it was too heavy to be effectively used. Source:

Given that designing a brand-new chassis would take time, the Germans went for the simplest possible solution. They simply reused what they had available, in the form of the obsolete Panzer I Ausf. B chassis. A 15 sIG 33 gun was placed on this chassis, protected by a three-sided armored superstructure. This led to the creation of a rather awkward vehicle, that on the one hand solved the problems with the mobility of the 15 cm gun, but was plagued with other issues. Namely, the chassis proved to be too weak and prone to malfunction due to the extra added weight. The crew was poorly protected and only a few rounds could be carried inside. Despite all the problems, a small production run of 38 vehicles was made, which was completed by March 1940. This vehicle is known as 15 cm sIG 33 auf Panzerkampfwagen I ohne Aufbau Ausf.B and was intended to be used as mobile artillery, although it was occasionally used in a direct fire role. While its gun was effective at close ranges, other factors, such as its high silhouette, poor armor, and weak chassis, made using it in such a way highly dangerous. Any kind of enemy anti-tank weaponry could easily take out this vehicle. In addition, since it was open-topped, the crew was completely exposed to enemy fire from above, something that was likely to occur in urban fighting.

A 15cm sIG 33 auf Panzerkampfwagen I ohne Aufbau Ausf.B of which some 38 would be built. Despite its clumsy appearance, the last vehicle would be lost in 1943. Source:
The sIG 33 auf Pz. I’s armor did not offer any real protection besides against small caliber bullets and shrapnel. Being hit by any properly designed anti-tank weapons could easily take it out of action or completely destroy it, like in this picture. Consequently, using such vehicles in close combat operations in urban areas was quite dangerous. Source: Digital Collection of Armin Freitag

Experience in Stalingrad

In the summer of 1942, the Germans and their allies launched a new offensive with the aim of capturing the resource-rich Caucasus, but also the strategic and politically important city of Stalingrad. The fighting around and for the city of Stalingrad was notoriously vicious. The Soviets desperately tried to defend it, as the loss of the city named after their leader would be a huge morale boost for the enemy. The Germans had to fight for every street and building. As the Soviets were well entrenched, the Germans had great difficulty dislodging them.

This issue was discussed at a meeting on 20th September 1942 between Army officials and Adolf Hitler. During the meeting, it was agreed that a new vehicle capable of leveling entire houses with a few rounds was desperately needed. It was to engage targets at close range, so it had to be well protected. Given the urgency of the project, a small series of 12 vehicles were to be built within a two-week period. This meant that this vehicle had to be built using existing tools and equipment. The armament chosen was the 15 cm SiG 33 heavy gun. For the chassis, the Panzer III and IV were to be tested to establish if this gun could be installed inside their turrets. As this proved impossible to achieve, as a temporary solution, the StuG III chassis was to be used instead. Given that the company Alkett was responsible for the construction of the StuG III, it was tasked with developing this new vehicle. In theory, the cheapest way to produce this modification would be to mount the 15 cm gun inside the StuG III. In reality, though, this was not possible due to the large size of the gun, so a completely new superstructure had to be designed from scratch. The frontal armor protection of this vehicle was to be 80 mm thick, which was one of the mightiest in the German arsenal at that time, excluding the heavy Tiger tanks, which were slowly entering service. Due to the urgency of the project, any available StuG III chassis were to be reused for the construction of this new vehicle. In essence, this meant reusing older chassis which were either used for training or were from damaged vehicles which were returned to Germany for repairs. StuG III chassis used ranged from the Ausf.A to Ausf.F.

The new vehicle was to reuse StuG III chassis from older models, in this case, an Ausf.D. The German industry had difficulty providing brand-new chassis for this project. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No.9 Sturmpanzer


This vehicle was simply designated as Sturminfanteriegeschütz 33. This name could be translated to infantry support assault gun. The number 33 refers to the main armament, the 15 cm sIG 33 (schwere Infanteriegeschutz – Heavy infantry gun). In the sources, it is sometimes also designated as 33B. The capital ‘B’ referred to the second version of this gun introduced in 1938. The sources occasionally shorten the name to StuIG 33. For the sake of simplicity, this article will use this shortened designation.


Given the urgency and rather simple conversion process for the StuIG 33, the first 6 vehicles were completed by 7th October 1942, and the remaining six three days later. On 13th October, all 12 were reported ready for service. The remaining 12 from the second series were reported ready by mid-November 1942. Given the vehicle’s improvised nature, and the fact that its design arose from the fighting at Stalingrad, no further vehicles were ordered.

A few of the StuIG 33s under construction. As the gun and the chassis were available, only the superstructure needed to be built from scratch. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No.9-1 Sturmpanzer

What is interesting is that in older sources, such as P. Chamberlain and H. Doyle’s Encyclopedia of German Tanks of World War Two, the first vehicle was stated as having been completed in December 1941. In a more recent publication, H. Doyle does not mention this date, which may suggest the older information has since been disproved with the appearance of more reliable information.


Even though the StuIG was built using any available StuG III chassis, there were some differences in the vehicles’ overall design. As these were more of an improvisation than a dedicated designed vehicle, this should not come as a surprise.


The StuIG 33’s hull can be divided into three major sections. These were the forward-mounted transmission, central crew compartment, and rear engine compartment. The front hull was where the transmission and steering systems were placed and it was protected by an angled armor plate. The two square-shaped, two-part hatch brake inspection doors were located on the front hull. The front glacis had two small round-shaped covers. Their purpose is unclear, but on the original Panzer III, starting from Ausf. E/F, enclosed air intake ports were placed in the exact position of these round-shaped covers. What is unusual is that the StuG IIIs were not provided with such an air intake port except for the Ausf.A/B hybrid which was built in small numbers. A more probable explanation may be found in the fact that after the conclusion of the Western campaign in June 1940, the German Army initiated a huge program intended to improve Panzer III’s overall performance. This included adding extra armor plates to the front and rear. The armor plates that were added to the front were usually bolted down. As these Panzer IIIs were provided with the front air intake ports, it would be necessary to add holes to the frontal armor plates. The Germans would have likely reused these plates, and the round holes were filled with round-shaped metal plates.

As different StuG III chassis were used for the StuIG 33’s construction, there were some minor differences between them. For example, the StuG III Ausf.E used smaller cast hinges for the two glacis hatches.

A StuIG 33 from the 23rd Panzer Division during the summer of 1943. The two round metal covers on the front hull can be seen here, next to the towing cables. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No.8 Sturmgeschütz
The unusual StuG III Ausf.A/B hybrid were used as a replacement for the delayed production of the later Ausf.B series. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No.8 Sturmgeschütz
After June 1940, most Panzer IIIs in service received a number of modifications including added frontal plates. To add these to the front hull armor plate, where the two air intakes were located, round-shaped holes had to be cut into them. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No.3-2 Panzerkampfwagen III Ausf.E, F, G, H.
The earlier StuG III versions used two large cast hinges for the two glacis hatches (left picture). Starting from the Ausf.E, four much simpler hinges were used instead. Those StuIG 33 that were built using the Ausf.E chassis did receive this small change. Source: Achtung Panzer No.5


The suspension was the standard StuG III type which consisted of six road wheels on each side. These were suspended using a combination of individual swing axles together with torsion bars which were placed in the bottom of the hull. The upper movement of each wheel’s swingarm was limited by bump stops covered in rubber. Additionally, the first and the last wheels were equipped with a hydraulic shock absorber.

Once again, due to its somewhat accelerated development, any StuG III chassis that was available at hand were reused for this project. This is visually most noticeable when observing the suspension, which often had mixed components from the older and newer StuG III versions. The use of different types of front drive sprockets and rear idlers was common on the StuIG 33. As these were intended to be used on the Eastern Front during the winter of 1942/43, wider Winterketten (English: Winter track) were often used. The added weight of the gun and the superstructure to the front of the vehicle caused huge problems with the front road wheels and the transmission, which were prone to breakdowns. This issue would occur later on in other German designs as well, such as the Jagdpanzer IV series. Whilst the Germans did some improvements, such as the use of internal suspended metal wheels, the StuIG 33 did not receive any such modifications. Basically, the driver would have to pay great attention during driving so as to not overstress the front transmission.

This particular vehicle uses the front drive wheel of an Ausf.A with a combination of return rollers and wider tracks of the Ausf.B. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No.9-1 Sturmpanzer
This vehicle had the new front-drive sprocket but uses the older rear idler design. Source:
The Ausf.C and D suspension introduced a new type of cast idler. The new cast idler (right) had a much-simplified design in contrast to an earlier version. Source: Walter J. Spielberger Sturmgeschütz and its Variants and
Given that the StuIG 33 was nose heavy, this led to mechanical issues with the front road wheels and the drive unit. Source: Digitial Collection of Armin Freitag


The StuIG 33 was powered by the standard StuG III twelve-cylinder, water-cooled Maybach HL 120 TRM engine giving 265 hp@2,600 rpm. With this power unit, the StuIG 33’s maximum speed was only 20 km/h. The reason for this drop in maximum speed is not quite clear. Given the vehicle’s weight at 21 tonnes, it was not much different from the later 23.9 tonnes StuG III Ausf.G. This StuG III version with the same engine could achieve a maximum speed of nearly 40 km/h.

The fuel load of 310 liters was stored in two fuel tanks placed below the radiators in the engine compartment. With this fuel load, the StuIG 33 operational range was 110 km on roads and 85 km cross-country. To avoid any accidental fires, these fuel tanks were protected by firewalls.

The engine compartment was protected by an enclosed superstructure. On top of this compartment, two two-part hatches were added for access to the engine. Further back, two smaller doors were added to provide the crew access to the fan drives. The air intakes were repositioned to the engine compartment sides and were protected with armor plates. One major change was the addition of a large storage box above the engine compartment.

The rear view of the StuIG 33. Notice the large storage box, positioned above the engine compartment. Source:


The superstructure had a simple box-shaped design. On the front part, there was the main opening for the gun mount, and to the left of it, the driver’s visor port was located. Right off the main gun, the machine gun ball mount was placed. The StuIG 33 had quite a limited field of view as no side or rear vision ports were provided. On the right side of the superstructure, a small pistol port was added.

To the rear, there were two hatches placed opposite of each other. Each of them had small pistol ports. On top, there was one hatch located in the bottom left corner. In addition, there was an opening for the gunner’s periscope. To avoid dust, rain, or, worse still, enemy grenades falling inside, a small protective roof was added on top of it. Lastly, there was a round opening for the ventilation port. Given that no such ventilation unit was fitted on any of the 24 StuIG 33 vehicles, it was simply covered by a round armor plate.

Side view of the StuIG 33’s simple box-shaped superstructure. Source: Wiki
Front view of the StuIG 33’s superstructure. In 1942, the Germans had trouble building 80 mm thick one-piece armored plates. As a temporary solution, they used a 50 mm and a 30 mm plate which were bolted together. Notice the small machine gun ball mount and the driver’s vision port. Source:
While the StuIG 33’s superstructure had a relatively simple design, it did not provide an adequate view of the surroundings for the crew. Source:
On the rear hatches and on the superstructure’s right side, in total, three small pistol ports were added. These would be used as close-defense firing points against enemy infantry. Source:
A top view of the StuIG 33 which was simply flat. Only one top hatch was provided for the commander, but there was no cupola for the commander. The opening for the gun’s periscope is covered by protective housing. Next to it, a ventilation port was welded shut. Although this vehicle would have certainly needed a ventilation fan to extract the fumes created from firing the gun, none were provided. The most likely reason for this is that the Germans could not produce them in time to fit them in. Source: Tank Power Vol.XXIV 15 cm sIG 33(Sf) auf PzKpfw I/II/III
A StuIG 33 built on an Ausf.E chassis and captured by the Soviets. This particular vehicle survived the war and is now located at the Kubinka Museum in Russia. The small pistol port can be seen here, located just behind the Balkenkreuz marking. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No.9-1 Sturmpanzer


The main armament of this vehicle was a 15 cm sIG 33. Rheinmetall began its development in 1927 and it entered service in 1933. With a total weight of approximately 1,700 kg, it was one of the heaviest guns to be ever used for infantry support. It was a reliable and robust gun that was easy to build and required very little maintenance.

In terms of construction, it was quite a conventional design. It had a two-wheeled carriage and the older type of box trail equipped with a hydropneumatic recoil system placed under the gun barrel. The gun possessed a high elevation and used a horizontal sliding-block breech mechanism. To help counteract the muzzle weight, two balancing springs (one on each side) were installed. The 15 cm sIG was considered a satisfactory weapon by the Germans, but the greatest issue was its weight. It would remain in use throughout the whole of World War II in both its original form and as the main weapon of many German self-propelled guns.

A gun crew loading a 15 cm sIG 33. Source: Wiki

The 15 cm sIG 33 fired a 38 kg heavy high-explosive round at a maximum range of 4.7 km. This high-explosive round, during the explosion, created a lethal area of around 100-120 m wide and 12-15 m deep. While the 15 cm sIG used several different ammunition types, in the sIG 33 auf Pz. I configuration, only the high-explosive rounds were used.

The main gun elevation was -4° to +75, while the traverse was 5.5° to either side. These figures differ depending on the source consulted. The rate of fire was low, at only 2 to 3 rounds per minute. This was due to the heavy weight of the shells and the use of separate two-part ammunition (shell and charges). The 15 cm sIG 33 used the Zeiss Rblf 36 gun sight.

The 15 cm sIG’s large ammunition is evident here. Source:

During the construction of the Panzer I modification, the whole gun with its trailing leg and wheels was simply placed on top of the Panzer I hull. While this made the replacement of damaged parts or even the removal of the gun itself easier, it added unnecessary weight and height. Given that the StuIG 33 was to have an enclosed superstructure, using a whole gun assembly was impossible. Luckily for the Germans, Škoda was developing a modified version of this gun, known as the 15 cm sIG 33/1. This version was intended to be used on Škoda’s own self-propelled gun project that was in the works but delayed due to the great need for anti-tank vehicles based on the Panzer 38(t)’s chassis. In this modified version, the 15 cm sIG 33/1 had its wheels and trail removed. As a result, the gun could easily be installed in any fighting vehicle capable of carrying its weight.

As Škoda worked on its own self-propelled version, it created the 15 cm sIG 33/1, which was designed especially to be installed in armored vehicles. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No.9 Sturmpanzer

The 15 cm sIG 33/1 gun was positioned slightly offset from the center to the right. The reason for this is not mentioned in the sources, but was possibly influenced by the driver’s position. The gun’s vertical rectangular opening was covered by a simple flat and sliding armor plate which moved with the gun when elevating. There were two parallel guiding rail plates bolted to the front armor, placed on opposite sides of the gun’s opening. The central opening for the gun was not fully protected, as there was some room between it and the gun barrel.

When the gun was highly elevated, there was an opening at its lower opening on the superstructure. To avoid potentially creating a death trap, the German engineers added a small sliding armor plate. When the gun mantlet plate was fully raised, it fell down and covered the small opening. This was a far from a perfect solution, but due to the urgency of the project, it was the best thing that the German engineers could think of.

The protective gun mantlet was not fully enclosed, as there was a small opening between it and the gun’s assembly. Notice the added sliding armor plate and the travel lock. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No.9 Sturmpanzer
Once the gun was elevated, the sliding armor plate would fall down and cover the opening left by the gun. Source: Digital Collections of Armin Freitag

The StuIG 33’s gun mount offered only a limited traverse of -3° to +3°, or -10° to +10°, depending on the source. Elevation ranged from -3° to +25°. Despite having a larger size than the smaller Panzer I, due to the 15 cm sIG 33’s large ammunition, only 30 rounds were carried inside the StuIG 33. When in movement, the gun was held in place by a forward-mounted travel lock.

The secondary armament consisted of one 7.92 mm MG 34 machine gun. It was placed on a Kugelblende 30 on the right side of the vehicle’s superstructure. The numbers 30 indicate the armor thickness of this ball mount. This ball mount consisted of two parts. The movable armored ball to which the machine gun was attached and the external and fixed armored cover. It offered a 15º traverse to either side. It could be elevated to 20° and depressed to -15°. For spotting targets, a telescopic sight with a field of view of 18° and 1.8 x magnification was provided. Only 600 rounds of spare ammunition were carried inside. Lastly, the crew was also provided with two 9 mm MP 40 submachine guns.

Close-up view of the Kugelblende 30. Source: P. Chamberlain and H. Doyle Encyclopedia of German Tanks of World War Two

Armor Protection

Given the specialized role that the StuIG 33 was to perform, it had to be well protected. Because the Germans had not yet fully introduced 80 mm thick plates, as a temporary solution, bolted armor was used. While it slightly complicated the overall production, the Germans never noted any major issue with bolted armor plates, which were commonly used on the StuG III series and other vehicles up to the war’s end.

The original StuG III’s chassis had frontal armor formed of two plates with a thickness of 50 mm and placed at 21° and 52° angles respectively. For the StuIG 33, the Germans added an additional 30 mm of frontal armor. The smaller lower hull plate, placed at 75°, remained 30 mm thick, while the sides and rear were 30 mm thick.

The front superstructure’s armor consisted of one 50 and one 30 mm thick armor plate, placed at an 81° angle. The side plates were 50 mm thick and placed at a 75° angle. The rear armor was flat and only 30 mm thick. The top was only 20 mm thick. The top engine compartment was lightly protected by 16 mm of armor.

Adding all kinds of spare equipment was often used as improvised armor. The most common way was to mount one or more spare wheels to the front of the superstructure. In addition, some crews added track holders, which were installed on the superstructure’s sides.

The crew of this vehicle added two road wheels to the front to act as spare parts, but as improvised armor protection too. Also, notice that spare track links were carried on the sides. Source:
This vehicle has only one spare road wheel added to its superstructure, but in a slightly different position to the previous vehicle. Source:


The crew of the StuIG 33 consisted of five: a commander, two loaders, a driver, and a gunner. The driver was positioned on the left side of the vehicle. Behind him was the gunner and after him the commander. While not specified in the sources, due to the radio’s 2 m antenna being positioned on the left, we can assume that the commander was also the radio operator.

The StuIG 33 was not provided with a command cupola, which limited the commander’s ability to scout the battlefield. Furthermore, the initial 12 produced vehicles were at first not even provided with scissors periscopes. Lastly, the two loaders would be placed opposite the previously mentioned crew members. One of them operated the machine gun.

The StuIG 33 had a crew of five, including the commander, gunner, driver, and two loaders. Source:
This vehicle, most likely belonging to the second series, was provided with the scissors periscopes for the commander. This was an essential piece of equipment, as the commander could observe a target and the battlefield without the need to expose himself to enemy fire. Source: Pinterest
The 2 m long radio antenna was positioned to the rear left part of the superstructure, which indicates that the commander may have acted as the radio operator too. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No.8 Sturmgeschütz

Combat Use

Immediately after completion, the first 12 vehicles were sent to the Eastern Front. They arrived at the River Chir, near the Don River, on 28th October 1942. Half of them were given to the Sturmgeschutz-Abteilung 117 (English: Assault Gun Battalion) and the remaining half to the 244th. Unfortunately, there is no surviving combat record of these 12 vehicles that saw service at Stalingrad. Given the heavy fighting, they likely saw extensive combat action.

The second group was initially attached to the 17th Lehr Abteilung, a training unit. Given the deteriorating situation at Stalingrad, especially after the Soviet encirclement of the 6th Army, these vehicles were part of the German relief force, which failed to break the enemy line. During this fighting, 5 vehicles were lost. The remaining 7 vehicles were allocated to the Gruppe Burgstaller (English: Burgstaller Group), essentially an ad hoc military unit, something that would become quite common for the Germans to do in later years. In April 1943, the Gruppe Burgstaller and its vehicles were integrated into the 23rd Panzer Division. The division itself was in the process of rearmament and reorganization, so any armor elements were welcome additions. As part of the 23rd Panzer Division, the StuIG 33s saw at least some combat action. At the end of May, this unit sent a combat report about the overall performance of the StuIG 33.

“ We advise close co-operation with tanks, since the self-propelled gun can destroy antitank guns and artillery positions at ranges up to 3,500m. Enemy tank assembly positions were effectively obliterated. We note that it is very effective against buildings, also infantry and anti-tank rifle positions. The gun did not achieve direct armor penetration when used against tanks. Mechanical maintenance is guaranteed only when used in conjunction with a tank regiment.

During the assault by our tank forces against concealed positions all were overrun and occupied. An advance in stages was carried out only under the cover of accompanying armored infantry. …. The mounting bolts on the [gun] cradle’s armor plate are too weak. The commander’s cupola is too small to provide good observation. The hatch impedes vision to the right. The vehicle is front-heavy. The second running wheels are overloaded. The engine is underpowered and the clutch is too weak, also the brakes wear out too quickly. “

On 11th May 1943, three vehicles were reported to be fully operational, while the remaining four were under repair. The last vehicle was reported lost in October 1943. Some sources also mentioned that at some point the 22nd Panzer Division briefly operated these vehicles.

A StuIG 33 from the Sturmgeschutz-Abteilung 224, possibly in or around Stalingrad in winter 1942. Source:
One StuIG 33 from the second production series, which was part of the 23rd Panzer Division, during summer 1943. Source:

Surviving Vehicle

Surprisingly, despite the limited number of the vehicles built, one StuIG 33 actually survived the war. It was captured at some point during the fighting for Stalingrad, and can now be seen at the Russian Kubinka Tank Museum.

The only surviving StuIG 33 vehicle at the Kubinka Tank Museum in Russia. Source: Wiki


While there is little to no information about the StuIG 33’s overall combat performance, we can assume that thanks to the 15 cm gun, it was quite effective in taking out designated targets. But given its rather improvised and rushed design, many flaws were noted. The vehicle was handicapped by low mobility and prone to breakdowns of the suspension and the drive unit. The gun, while effective, had limited traverse and a small ammunition load. The crew had poor vision of their surroundings, especially the commander. Despite all these flaws, the StuIG 33 showed that such a vehicle was needed, and further development would lead to the introduction of an assault gun known as Sturmpanzer IV, which saw service in greater numbers.

German Sturminfanteriegeschütz 33B equipped with the 15 cm sIG 33 howitzer for close infantry support, Stalingrad, fall 1942. Only 12 were deployed here, out of the 24 converted. Illustration by Tank Encyclopedia’s own David Bocquelet.

Sturminfanteriegeschütz 33 Specifications

Size (L-W-H) 5.4 x 2.9 x 2.3 m
Weight 21 tonnes
Crew 5 (driver, commander, gunner, two loaders)
Engine Maybach HL 120 TRM 265 hp ​​@ 2,600 rpm
Speed 20 km/h
Range 110 km / 85 km (cross-country)
Armament 15 cm sIG 33/1
Armor 15 to 80 mm


D. Nešić (2008) Naoružanje Drugog Svetskog rata-Nemačka, Beograd
T.L. Jentz and H.L. Doyle (1999) Panzer Tracts No.8 Sturmgeschütz
T.L. Jentz and H.L. Doyle Panzer Tracts No.9 Sturmpanzer
P. Chamberlain and H. Doyle (1978) Encyclopedia of German Tanks of World War Two – Revised Edition, Arms and Armor press.
H. Doyle (2005). German military Vehicles, Krause Publications
Ian V. Hogg (1975) German Artillery of World War Two, Purnell Book Services Ltd.
T. L. Jentz and H. L. Doyle (1998) Panzer Tracts No.10 Artillerie Selbsfahrlafetten
J. Engelmann, Bison und andere 15 cm-Geschutze auf Selbstfahrlafetten, Podzun-Pallas-Verlag GmbH
Tank Power Vol.XXIV 15 cm sIG 33(Sf) auf PzKpfw I/II/III, Wydawnictwo Militaria
Walter J. Spielberger (1993) Sturmgeschütz and its Variants, Schiffer Publishing Ltd
T. Anderson (2016) Sturmartillerie Spearhead Of the Infantry, Osprey Publishing
W. J. Spielberger (2007) Panzer III and its Variants, Schiffer Publishing Ltd.
B. Carruthers (2012) Sturmgeschütze Armored Assault Guns, pen and Sword

WW2 German Assault Guns

Beute Sturmgeschütz L6 mit 47/32 770(i)

German Reich (1943-1945)
Light Self-Propelled Gun – 194 Captured and Produced

The Semovente L40 da 47/32 was an Italian light Self-Propelled Gun (SPG) developed as an infantry support vehicle. It entered service in 1942, immediately proving to be obsolete. The Regio Esercito (Eng: Italian Royal Army) used it until September 1943, when the Cassibile Armistice was signed, the Italian Royal Army was disbanded and the Italian peninsula not yet under Allied hands was occupied by the German troops.

After the armistice, from 1943 to 1945, all the surviving Semoventi (Italian world for self-propelled guns, Semovente singular) that were deployed, not only in Italy, but also in the Balkans, were captured by the armies or militias in the area.

The Semovente L40 da 47/32

The development of a new light infantry support gun that could support the assault of the Bersaglieri units (Eng: Italian Light Assault Troops) started in the late 1930s, but the first two prototypes were not accepted into service.

Another prototype development started in January 1941. On May 10th, it was presented to the Royal Army. After the tests, the Italian Royal Army High Command requested some changes to the prototype. It was renamed Semovente Leggero Modello 1940 da 47/32 or Semovente L40 da 47/32 (Eng: Lightweight Self-Propelled Gun Model 1942 armed with 47/32).

A total of 402 vehicles were produced under Italian and German control based on the hull of the L6/40 light reconnaissance tank.

German Operation Achse

After the arrest of Benito Mussolini, the leader of the Partito Nazionale Fascista Italiano (Eng. Italian National Fascist Party), on July 25th 1943, the Germans had foreseen the Italian surrender. They planned Fall Achse (Eng: Operation Axis), which they launched on September 8th when the signing of the Armistice of Cassibile (which had been secretly signed on September 5th by the Italian Royal Army and Allied Forces) was made public. In 12 days, the German troops managed to occupy all the Italian command centers and divisions in Italy and in the other occupied territories.

The Germans captured all the Italian factories that produced armaments or military equipment. They also captured 977 Italian armored fighting vehicles, of which about 400 were tanks and self-propelled guns, 16,631 trucks, over 5,500 artillery pieces, 2,754 anti-tank or anti-aircraft guns, over 8,000 mortars, 1,285,000 rifles, 39,000 machine guns, and 13,000 submachine guns. They imprisoned 1,006,730 Italian soldiers stationed in Italy, the Balkans, Greece, and France.

By October 1st, 1943, Wehrmacht documentation stated that German units had captured 78 L40 da 47/32s in all occupied territories (including the 20 L40s produced before the Armistice and not delivered). In German service, this vehicle was known as the Sturmgeschütz L6 mit 47/32 770(i). For this reason, some sources wrongly call it Semovente L6 or StuG L6.

In addition, many former Italian factories, such as FIAT, Lancia, Breda, and Ansaldo-Fossati, were also under German control. With this and with the acquisition of many spare parts and materials, it was possible to restart the production of nearly all Italian vehicles. This was the case with the Semovente L40 da 47/32, with the Germans producing 74 new Sturmgeschütz L6 mit 47/32 770(i).

Under German control, another 46 Command and Radio Center vehicles on the L40 hull were produced, which brings the total number of L40 produced by the Germans to 120 units.

Operational service in Italy

While the Semovente L40 da 47/32s were available in some numbers, their use in Italy by the Germans was limited. The units that had this vehicle in Italy were the 305. and 356. Infanterie Divisionen, Schwere Panzerjäger Abteilung 590, 114. Jäger Division and the 20. Luftwaffe-Field-Division.

The 305. Infanterie Division fought between September 8th and 10th to occupy the port of La Spezia. It was transferred in the following weeks to near Rome, where it was supplied with some Italian vehicles, among which were some L40 from 47/32s.

The 305. Division then defended the Gothic Line and the Gustav Line before surrendering, together with most of the German divisions that remained after the Battle of Bologna, on the Po River.

The 356. Infanterie Division fought in anti-partisan actions between November 1943 and January 1944. It was transferred to Anzio and was provided with the self-propelled L40 vehicles along the way.

The unit fought fiercely for the defense of the region together with the Italian Republican National Army units until they were forced to retreat along the Gustav Line in March 1944. After the Gustav Line was broken through, the unit fought in Tuscany. retreating to the south of Florence in July 1944. In January 1945, it was transferred to Hungary but, according to the surviving documents, it was no longer equipped with Italian self-propelled vehicles.

The Schwere-Panzerjäger-Abteilung 590. was used from June 13th to September 14th, 1944 to secure central Italy. In order to perform this task, the unit was provided with some L40 self-propelled vehicles. From September 15th, 1944 to January 15th, 1945, the unit was involved in defensive combat in the Emilia-Romagna region.

Due to the scarcity of artillery towing vehicles and the obsolescence of the self-propelled L40 variants, many self-propelled vehicles were modified by removing the cannon to be used as artillery tractors.

From April 22nd to May 2nd, 1945, the unit was involved in the fighting retreat, desperately battling against the Allied forces.

The 114. Jäger Division was transferred to Italy from Yugoslavia in January 1944. It was supplied with material captured from the Italian Army, including some L40 self-propelled vehicles. After the Battle of Anzio, the unit was employed only in anti-partisan roles. It was responsible or co-responsible for three different massacres in the region of central Italy against innocent civilian victims. The unit was completely annihilated in April 1945 during fighting with Allied forces.

This Semovente L40 da 47/32 was used to tow a German 7.5 cm PaK 40 anti-tank gun. Source:

Panzer-Ausbildung-Abteilung-Süd (a training tank battalion) was equipped with the Semoventi L40s, but these were used mainly for crew training. Organization Todt, which was present in Italy, operated an unknown number of L40 da 47/32s, but mostly as tractor vehicles without their guns.

In May 1944, the 20. Luftwaffe Field Division (20. LwFD), previously employed in Denmark, was sent to Italy, more precisely to Lazio. There, it was re-equipped with a number of Semoventi L40 da 47/32s and immediately participated in hard clashes with the U.S. Army units in the Terracina area. On June 1st, the unit assumed the designation of 20. Luftwaffen-Sturm-Division.

The division retreated to Tuscany and established defensive positions near Roccastrada. From there, at the end of June, it was again engaged in heavy clashes against U.S. forces.

After fighting house by house for the control of Siena against the units of the Corps Expéditionnaire Français en Italie (Eng: French Expeditionary Force in Italy), in July 1944, the division withdrew to the area of Volterra. It was then withdrawn from the front to be sent to the rear to guard the coast between Viareggio and La Spezia, where it absorbed the remains of the 19. LwFD. In mid-September, the division received orders to move to the coast of the Adriatic Sea, facing the Commonwealth forces between Rimini and Santarcangelo di Romagna and then south of Cesena.

After the killing of their commander in Bologna by the partisans and further heavy losses in the fighting between Cesena and Forlì, the division was disbanded on November 28th, 1944 and its survivors were reassigned to other German units.

Some Semoventi L40 da 47/32s were used as training vehicles. These had their guns removed and a wooden shield added instead. This vehicle possibly belonged to the Panzer Ausbildung Abteilung Süd. Source:

Operational service in Balkans

In the Balkans, the L40 da 47/32s saw extensive use against Yugoslav resistance movements. Several German units were equipped with them. Some of these were the 117. and 118. Jäger Divisionen, 11. Luftwaffe-Field-Division, and the 181., 264. and 297. Infanterie Divisionen. Many police units of different sizes (such as the 13. Verstärkt Polizei Panzer Kompanie, 14. Panzer Kompanie, 4. SS Polizei Division) were also equipped with this vehicle. Some smaller units were also supplied, such as SS Panzer Abteilung 105. and Panzer Kompanie z.b.V 12.

In 1944, due to the availability of Italian armored vehicles, it was possible to resupply many German units which fought in Yugoslavia with them. The Germans did not form dedicated Panzer units with these vehicles. Instead, these vehicles were usually used to equip reconnaissance or anti-tank units (Aufkl. Abt and Pz.Jag. Abt.). By May 1944, German forces operating in Yugoslavia had at least 165 Semovente 47/32 vehicles.

By the end of 1943, Panzer Kompanie z.b.V 12 had in its inventory 12 operational Semoventi L40 da 47/32s and 4 in repair. In early 1944, it received an additional 14 Semoventi da 47/32, one L6 light tank, and 4 M13/40s. By February 1944, there were only 2 operational Semoventi da 47/32 and 2 in repair. On March 1st, 1944, some 10 were operational and 3 in repairs. These were allocated to the 2nd Company, which took action against partisan units around the city of Kraljevo. In July, the number of Semoventi da 47/32 was increased to 15 vehicles. The reason for the large monthly oscillations in available numbers is not clear. It could be either a mistake in sources or, because of the poor mechanical reliability, some vehicles were simply not listed. By September and October 1944, while this unit still had 16 such vehicles, they were replaced in order to increase the number of M15 tanks.

The 14th Panzer Kompanie was another example of a German unit using the Semovente L40 da 47/32. This unit, which was active in Slovenia in September 1944, was reinforced with two 8 vehicle strong platoons equipped with the Semovente L40 da 47/32. One smaller unit with four such vehicles was kept in reserve.

While fighting the Partisans in the Balkans, the L40 da 47/32s were usually dispersed and used in smaller groups. The usual tactical employment was that one vehicle would advance while the remaining vehicles provided cover.

By the end of 1944, on the Yugoslavian Front, the Germans and their allies had less than 80 Semoventi L40 da 47/32. Near the end of the war, in March 1945, the numbers were reduced to less than 40.

A column of armored vehicles belonging to the German 13th Verstärkt Polizei Panzer Kompanie. In the foreground is a Panzer IV Ausf.F followed by three Italian tank destroyers. Source: Bojan B. Dumitrijević and Dragan Savić Oklopne jedinice na Jugoslovenskom ratištu
A pair of Semovente L40 da 47/32s of the third series in German hands. Notice the addition of a machine gun and a gun shield on the roof of the vehicle. Source:

In German hands, the Semovente L40 da 47/32 was modified in order to improve its performance. As the L40 da 47/32 was initially only armed with the main gun, it was less effective against infantry attacks. For this reason, the Germans added machine gun mounts that were protected with an armored shield at the front. The machine gun models used included the Breda Mod. 37 and Breda Mod. 38, both 8 mm caliber, and, in some cases, MG34s or FIAT-Revelli Mod. 14/35. Additional armor plates were added to the side of the superstructure, and in some cases, even on the top. Additional spare part boxes were also sometimes added.

Also, as previously noted, a significant number of these vehicles were modified to be used as towing tractors or as training vehicles. For these modifications, the main gun was removed. In the case of the training vehicles, a wooden shield was simply added where the gun was.

A Semovente L40 da 47/32 of the second series in Baranja (Serbia) at the start of 1945. Interestingly, this vehicle appears to be armed with a German MG 34 machine gun. Source: Bojan B. Dumitrijević and Dragan Savić Oklopne jedinice na Jugoslovenskom ratištu

The SS Polizei-Regiment 18 Gebirgsjäger was equipped with two Italian armored cars and at least five Semoventi 47/32s when it was relocated from Greece to the northern regions of Serbia in October 1944. It was engaged in a failed German attempt to stop the advancing Soviet Forces in Vojvodina and suffered heavy losses, probably losing all its vehicles.

In general, the German view of the L40 was very negative. It was small and narrow and the cannon was not able to face the most modern opponent vehicles. In anti-partisan actions in Italy and in the Balkans, it proved relatively effective, as its small shape and weight allowed it to climb very steep mountain roads, where only mules could pass. The cannon, even if almost useless against the armor of Soviet or American tanks, had a good High Explosive round that was effective against infantry.

The Germans, as well as the Italians, realized that the vehicle was very vulnerable to ambushes. Consequently, German tankers learned to wear the Stahlhelm helmet and carry MP40s and hand grenades inside the vehicle for close defense.


The Germans repainted the L40s that they captured from the Italians or that they received after November 9th with a three-tone camouflage, depending on the unit that used them.

For example, Schwere Panzerjäger Abteilung 590 repainted its L40 da 47/32s with dark green and dark brown stripes on a standard khaki base. SS Polizei-Regiment 18, stationed in Greece, repainted its vehicles in three-tone camouflage, dark green, and brown spots on standard khaki. The 20. Luftwaffen-Feld-Division, which used some L40s in anti-partisan duties in central-northern Italy, camouflaged its self-propelled guns vehicles with patches of green and dark brown.

Semovente L40 da 47/32 of the SS Polizei-Regiment 18 in Athens during a parade May 23rd, 1944. Note the three-tone camouflage pattern. Source:
A Semovente L40 da 47/32 Platoon Command vehicle used by the 20. Luftwaffen-Feld-Division near Lucca, Italy Summer 1944. The original Regio Esercito plate (R.E. 5282) is clearly visible near the big Balkenkreuz, drawn to avoid friendly fire. Source:


The Semovente L40 da 47/32, while cheap and small in size, was by 1943 standards generally an obsolete vehicle. For the Germans who were at this stage of war becoming ever more desperate to find any additional armored vehicle, it was a welcome addition. The use of the Semovente L40 da 47/32 by the Germans in its original role against the Allied forces in Italy was limited. They did see service in other secondary roles for example crew training or as armored tractors. They were more deployed in combat against the Partisans especially in the Balkans where the enemy had limited anti-tank capabilities.

German StuG L6 mit 47/32 630(i), summer 1944. Illustration by David Bocquelet.

Semovente da 75/18 specifications

Dimensions (L-W-H) 3.82 x 1.92 x 1.63 m
Total Weight, Battle Ready 6.5 tons
Crew 3 (commander/gunner, driver, loader)
Propulsion FIAT-SPA, 6 cyl. gasoline, 68 hp
Speed (road) 42 km/h (off-road) 20/25 km/h
Range 200 km on-road
Armament Cannone da 47/32 Mod. 1935, 70 rounds
Armor 30 mm front, 15 mm sides and rear, and 10 mm floor
Total Production 74 Semoventi L40 da 47/32 captured and 120 produced under German control in all variants


Bojan B. Dumitrijević and Dragan Savić (2011) Oklopne jedinice na Jugoslovenskom ratištu,, Institut za savremenu istoriju, Beograd
T. L. Jentz (2008) Panzer Tracts No.19-2 Beute-Panzerkampfwagen
F. Cappellano and P. P. Battistelli (2012) Italian Light tanks 1919-45, New Vanguard
Nicola Pignato e Filippo Cappellano – Gli autoveicoli da combattimento dell’Esercito Italiano, Volume secondo (1940-1945).
Filippo Cappellano – Le artiglierie del Regio Esercito nella Seconda Guerra Mondiale
Nicola Pignato – Armi della fanteria Italiana Nella Seconda Guerra Mondiale
Olivio Gondim de Uzêda – Crônicas de Guerra

Has Own Video WW2 German Assault Guns

Sturmgeschütz IV für 7.5 cm Sturmkanone 40 (Sd.Kfz.167)

German Reich (1943)
Assault Gun – 1,141-1,500 Built

When the Alkett factory was heavily bombed by the Allied Air Force in November 1943, the production of the StuG III was almost put to a halt. In an attempt to find a relatively easy solution, the Germans simply merged the Panzer IV chassis with a StuG III upper superstructure, creating a new vehicle, the StuG IV. Production was conducted relatively quickly, with 30 vehicles completed by December 1943 and, by April 1945, over 1,000 would be built. Like its StuG III cousin, the StuG IV was also an effective assault gun which would see service on all major fronts up to the end of the war.

The StuG IV. Source:

Sturmgeschütz concept

During the Great War, German (and many other nations) infantry formations were supported by towed artillery. For German Sturmtruppen (Eng. Stormtroopers) that depended on mobility. The necessary towed artillery proved to be slow and inadequate for the supporting task in taking more fortified enemy positions. Based on this experience, after the war, the great German Army tactician, General Erich von Manstein, proposed using highly mobile, well protected and armed self-propelled artillery. They were to provide infantry with mobile close fire support during combat operations. These were to be organic part of standard Infantry Divisions at a battalion strength of around 18 vehicles.

Due to Germany’s general lack of production industrial capacity during the 30’s, it would take years before the first prototypes were completed. The Germans were also forbidden by the Versailles Treaty to develop and produce tanks, which Hitler, when he came to power, publicly denounced. The development of these vehicles was also hindered by conflict in different branches of the Germany Armed Forces. Eventually, it was decided that these vehicles would be put under direct supervision of the Artillery. These vehicles would be known as Sturmgeschütz III (assault gun vehicles) but were generally known simply as StuG III.

To speed up the development, it was decided to reuse many elements of Panzer III vehicles. The design was very simple and consisted of a new superstructure armed with a short barrel 75 mm gun placed on the Panzer III chassis.While the first prototypes were completed in 1937, it was not until 1940 when the initially limited production actually started. Once pressed into service, the StuG III proved to be an excellent infantry support vehicle. When the Germans invaded Soviet Union in 1941, the Germans noticed that their available anti-tank weapons were almost useless against the Soviet modern tank designs (T-34 and KV’s). To address this problem, in 1942 the Germans introduced a new StuG III armed with the longer 75 mm gun that was more effective as a tank destroyer. As production of the StuG III shifted more towards the anti-tank role, the Infantry was left without a proper support vehicle. To address this, a new version of the StuG III armed with a 10.5 cm howitzer was introduced in 1943. Both versions would remain in production until the war ended with over 10,000 being produced, making them the most numerous German armored vehicle of the war.

The 75 mm L/24 short-barreled StuG III served as an excellent infantry support weapon during the war. Source:
To address the ever increased threat of more advanced enemy armor the Germans upgraded the StuG III with the longer L/43 and later L/48 75 mm anti-tank guns. Source:

The first StuG IV

In early 1943, Albert Speer approached Krupp officials with a suggestion for producing a new Sturmgeschütz. Soon after, Krupp began working on the first basic drawing of this vehicle, which was to incorporate a number of already produced components. These include a StuG III Ausf.F superstructure, Panzer IV Ausf.H chassis and a 7.5 cm StuK 40 L/48 gun. The superstructure of the StuG III Ausf.F was chosen as, at that time, Krupp did not possess the design plans for the newer Ausf.G version. Unlike the later produced Sturmgeschütz based on the Panzer IV that used the unchanged StuG III superstructure, the initial Krupp design was different. The front part of the superstructure incorporated a highly angled (50 mm thick) armor plate which would have provided excellent protection. Other changes included increasing the armor protection on the sides to 45 mm, compared to the original 30 mm, and the increase of the track’s width.

Drawing of Krupp’s initial project for the new StuG vehicle based on the Panzer IV chassis. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No.20-1 Paper Panzers

After the first drawing and calculation were completed, Krupp informed the Germany Army and Wa Pruf 6 officials that, although it was feasible, they did not recommend producing it. Despite removing the turret, the vehicle would have the same weight as an ordinary Panzer IV tank. In addition, the redesign and sloped armor would cause production delays which were not acceptable at that time, so the project was quickly abandoned.

A new start

While the idea for a new StuG vehicle based on the Panzer IV chassis was discarded, several months later, due to desperate necessity, it would come to life again. In November 1943, the Allies heavily bombed the Alkett factory which was instrumental for the overall StuG III production. As the production of vital StuG III vehicles was temporarily stopped, the Germans needed a new quick solution. At a military conference held in early December 1943, Adolf Hitler was informed that the StuG III Ausf.G superstructure could be, with minimal effort, mated with a Panzer IV Ausf.H or J chassis. This time, however, the new vehicle had to have minimal changes to the components used for its construction. The only major modification was the extension of the driver compartment. Hitler was impressed with this proposal, as it would be easy to implement due to available parts and production capabilities. Hitler also suggested giving this new vehicle to the Panzer Abteilungen, as it would facilitate maintenance and procurement of spare parts.

The negative side of this decision was the reduction of available chassis for the Panzer IV tank. But, as the production of the Panzer IV was to be terminated in favor of larger Panther tanks, this was not seen as a huge issue. The actual production of the Panzer IV, due to the high demands for tank vehicles, was never canceled and it lasted almost up to the end of war. As the need for the StuG III vehicles was great, Hitler gave a green light for the realisation of the project.


According to Hitler’s initial orders, the StuG IV was to be produced in great numbers in a short period of time. Some 350 vehicles had to be built in December 1943 and an additional order of 500 to be built by the end of January 1944. Of course, this was impossible to achieve given Germany’s dire economical and industrial situation.

Despite these optimistic numbers given by Hitler, Krupp actually received orders to produce the first 10 trial vehicles at the end of 1943. Nevertheless, Krupp managed to quickly produce 30 vehicles by the end of December 1943. The production goal for January and February 1944 was 210, whereas Krupp managed to produce 214 vehicles. During 1944, monthly production goals were around 90, with the exception (beside January and February) of November, with 100, and December with 110 vehicles. Despite the bad economical situation and the Allied bombing raids, Krupp managed to obtain a relatively smooth production run. 87 vehicles were built in March, 91 in April, 90 in June and July, 70 in August, 56 in September, 84 in October, 80 in November, and 49 in December 1944. In 1945, the production numbers dropped down severely due to many factors, but probably most important were the Allied bombing raids and lack of resources. In January 1945, the number of produced StuG IVs was 46, 18 in February, 38 in March and the last 3 were completed in April. By the time the production run stopped in April, Krupp had managed to produce 1,111 Stug IV vehicles. Beside Krupp, Alkett also produced some 30 StuG IVs with the chassis provided by Nibelungwerke.

Of course, like many other German production numbers, there is some disagreement between authors. The previous mentioned numbers are according to T. L. Jentz and H. L. Doyle in Panzer Tracts No.23 Panzer Production from 1933 to 1945 and Walter J. Spielberger in Sturmgeschütz and its Variants. A. Lüdeke (Waffentechnik im Zweiten Weltkrieg) suggests 1,500 produced vehicles. On the other hand, D. Nešić (Naoružanje Drugog Svetsko Rata-Nemačka) estimates that some 1,139 were built from December 1943 to March 1944 (this year is probably a print or author error). An interesting number is the 632 built vehicles speculated by B. Perrett (Sturmartillerie and Panzerjager 1939-45). This is almost less than half the numbers that all other sources give and it is likely incorrect.

While the final assembly, together with the manufacturing of chassis and running gears, was done by Krupp, all other necessary components were supplied by other companies. Additional frame chassis were supplied by Eisen Hüttenverein, Eisenwerke Oberdonau, Krupp (Essen) and Böhler. The guns were built by Škoda and Wimag. The StuG III superstructure was provided by Brandenburgische Eisenwerke.

One of the first produced StuG IVs at the end of 1943. Source:


Being designed to supplement the StuG III, this vehicle also inherited its name of Sturmgeschütz IV für 7.5 cm Sturmkanone 40. In general, it was also simply known as StuG IV, which this article will use for the sake of simplicity.


As previously mentioned, this vehicle was built using a combination of Panzer IV and StuG III elements. Thus, it was logical that the changes introduced on the StuG III were also implemented on the later StuG IV. The manufacturers of Panzer IV chassis were not always informed in advance for which role their chassis would be used (for ordinary tanks or assault guns). Many changes that were to be introduced to later built StuG IVs were not necessarily always applied to all vehicles.

The Hull

The StuG IV hull was built using surface-hardened steel plates which were welded together. It was divided into the rear engine compartment, the central crew compartment and the forward-mounted transmission and the new enclosed driving compartment. While, originally, the Panzer IV hull had an emergency escape hatch door placed beneath the radio operator’s seat, it was removed on the StuG IV. This was done mainly due to changing the position of the radio equipment.

The front hull was where the transmission and steering systems were placed and was protected with an angled armor plate. To gain better access for repairs, a square-shaped transmission hatch located in the middle of this plate and two rectangular steering brakes inspection hatches with ventilation ports were added.

The Superstructure

The vehicle’s superstructure design was more or less a copy of that of the StuG III. It consisted of a box shaped base with angled frontal armor plates. The most obvious change was the introduction of a new box-shaped driver compartment which protruded to the front. On top of it there was a hatch door and two periscopes with armored covers. Initially, there was a problem with the hatch door accidentally closing back and potentially injuring the driver. Thus, it was changed to include a mechanism that locked the door in the open or closed position. Just above the driver compartment, during the production run, a rain guard was added to avoid water getting to the driver. In addition, as the Panzer IV chassis was longer, next to the new driver compartment, an armored plate was bolted down to fill the gap.

As the Panzer IV chassis was longer than the original StuG III, the opening next to the driver compartment was simply closed up using a bolted plate. This plate is visible just under the main gun. Source: J. Ledwoch Sturmgeschütz

On the top left of this superstructure, a command cupola was placed. On its hatch, there was a second smaller hatch which allowed the commander to use a periscope to observe possible targets. The design of the commander’s cupola changed during the production. Initially, welding was used during its construction while, later in the war, some elements were cast. While a rotary cupola was more desirable, due to production problems, it was only fit from August 1944 onwards. The frontal part of the cupola was reinforced with a protective deflector , which proved to be a weak spot on the earlier StuG III.

In front of the command cupola, there was a sliding plate which held the gunner’s retractable stereo telescope. On the superstructure’s right side, the loader’s two-part hatch was placed. This would be replaced by a single-piece hatch later in production.

Front view of the new box-shaped driver compartment, with its two protected sights. Just above the comparpent, the diagonal line is a rain guard. On top of the superstructure, the commander cupola was placed. Its hatch had an additional smaller hatch that the commander could use for his own telescopic periscope. Source: Walter J. Spielberger Sturmgeschütz and its Variants

From June 1944, the newly produced StuG IV received mounts placed on top of the superstructure. Their purpose was to be used to mount a fold-up crane with a lifting capacity of some 2 tonnes, to help with maintenance and repairs. The superstructure top was held in place by a simple bolt and, if needed (for example to change the gun), could be easily removed. On the rear flat armor of the superstructure, a ventilation port was added. It was protected by an armored cover.

The StuG IVs produced from mid-1944 on had an option to install a 2 tonne crane to help with the vehicle’s repairs and maintenance. Source: Walter J. Spielberger Sturmgeschütz and its Variants
The protective ventilation port is placed to the superstructure’s rear. Note this picture is from a StuG III but the superstructure was in essence the same. Source: Walter J. Spielberger Sturmgeschütz and its Variants

Suspension and running gear

The suspension consisted of eight small (470 x 75 x 660 mm) wheels placed on each side, suspended in pairs and placed on four bogie assemblies. The small road wheels were suspended by leaf-spring units. The distance between each bogie shaft was 500 mm. There were also four return rollers (250 x 65 x 135 mm) on each side. While use of three return rollers per side was tested in June 1944, its implementation on StuG IV vehicles was delayed up to December 1944. Due to the shortage of rubber, steel return rolles were used instead on many vehicles. At the front, two drive sprockets were placed. To the rear, the two (650 mm) idlers had an adjustable track tensioning mechanism.

Close up view of the unchanged Panzer IV suspension. Source:

The ground clearance of this vehicle was 40 cm. While the StuG IV used standard Panzer IV tracks, for operating in the East and during Winter, specially designed and wider Ostketten tracks would be employed.

This vehicle was equipped with enlarged Ostketten tracks. Additional track links were placed on the front of the hull to act as spare parts and improvised armor. Source: Worldwarphotos

The Engine and Transmission

The engine compartment was mostly left unchanged. The StuG IV was powered by a standard Maybach HL 120TRM, which produced 265 hp@2600 rpm. With a weight of nearly 26 tonnes (or 23 depending on the source), the maximum speed was 38 km/h (or 20 km/h cross-country) with an operational range of 220 km and 130 km cross country. Some sources give a number of 320 km and 198 km cross country. The fuel load of 450 l (430 and 470 l capacities are also listed in different sources) was stored in three fuel tanks placed under the crew fighting compartment. The engine and the crew compartment were separated by a fire resistant and gas-tight armored firewall. This compartment was provided with an automatic fire extinguisher system. While the Ausf.H chassis used a canister shaped muffler, the later Ausf.J used two vertical Flammentöter mufflers.

The two vertical Flammentöter mufflers indicate that this is a Panzer IV Ausf.J chassis. Source: Pinterest

According to Wa Pruef 6’s instructions to Krupp beginning in March 1944, the auxiliary DKW gasoline engine that was originally used to provide traverse for the Panzer IV’s turret was to be removed from tanks. To use the extra available space, Krupp engineers added additional fuel tanks instead of the DKW engine. While using this as an auxiliary ammunition bin was briefly considered, it would require removing parts of the firewall, which only would delay and complicate production. This also carried over to the StuG IV.

The ZF SSG 75S six-speed (and one more for reverse) transmission was connected to the engine by a drive shaft that ran through the bottom of the fighting compartment. The steering mechanism was the same ‘Wilson’ type which was designed and produced by Krupp.

The Armor Protection

The frontal armor protection of the StuG IV was relatively good. The upper front glacis armor plate was 20 mm thick at a 70° angle, front glacis was 80 mm placed at a 12° angle and the lower glacis was 30 mm placed at a 60° angle. The side armor was 30 mm thick, the rear was 14.5-20 mm and the bottom was 10 mm.

The front superstructure armor was 80 mm thick, with the upper armor 30 mm placed at a 50° angle. The 80 mm thick frontal armor on some vehicles was increased with an additional 30 mm armor plate. The additional armor plate was held in place using six bolts. As this proved too difficult to be accomplished in the field, those that received the extra plate were instead connected using welding. The extended armor plate of the superstructure was 50 mm thick placed at 15° angle. The sides were 30 mm at a 10° angle.

The flat mantle was protected by 50 mm of armor. The rear part of the superstructure was 30 mm thick. The superstructure and engine compartment top parts were 10 mm thick. The commander’s cupola had all-around 30 mm of armor. The new extended driver compartment was protected with 80 mm front and 30 mm side armor.

The StuG IV, similar to many other German vehicles, could be equipped with 5 mm thick side protective skirts, known in German as Schürtzen. The primary mission of these was to provide extra protection from Soviet anti-tank rifles. During rail transport, the protective skirts could easily be taken down and later put back on again. Some were also protected by Thoma Schürtzen wire mesh. While these were lighter and provided the same level of protection, their use was delayed due to problems with production. The use of Zimmerit anti-magnetic mine coating was quite common, though, by the end of September 1944, it was no longer applied to the StuG IV.

A brand new Stug IV with Schürtzen protective skirts. Source Pinterest

Crews would often make improvised attempts at uparmoring their vehicles, hoping to increase the combat survivability of the StuG IV. A somewhat common practise was adding layers of concrete (to a greater or lesser extent) on the front part of superstructure (this was also done on some other vehicles, such as the StuG III). This improvised concrete armor proved to be ineffective in combat. Even the General Artillery Inspector gave a report stating that this improvisation was almost useless. Nevertheless, many StuG IVs continued to receive ‘concrete armor’ up to the war’s end. Other crews added what they had at hand, ranging from captured enemy or own tracks, spare parts, such as road wheels, and some even added logs or ordinary wooden branches. Some vehicles were equipped with extra armor plates welded to the front and placed at great angles. The effectiveness of these improvised attempts was more psychological than realistic.

This vehicle had the usual concrete armor added to the front. The space between the vehicle superstructure and the Schürtzen was filled with wooden branches. Source:
This vehicle had wooden logs put on the superstructure sides. The log may have been used for other purposes too, not just for protection. Source: Pinterest
Besides the concrete armor, the most common practice for the StuG IV (and on many other German vehicles) was to use spare tracks. Sometimes even those captured from the enemy. Source: worldwarphotos
The crew of this particular vehicle (left abandoned in Italy, 1944) added an extensive concrete layer on the driver compartment. In addition, tracks and two armor plates were also added. One extra armor plate was to the front and the second, somewhat unusually, atop the gun mantlet. and Source: J. Ledwoch Sturmgeschütz IV

The Crew and Radio

The StuG IV had a crew of four, which consisted of the commander, gunner, loader and driver. The driver was positioned to the vehicle’s left front side of the hull, in the box-shaped driver compartment. Just behind him was the gunner. To the rear of the gunner was the commander, who had a command cupola for better observation of the surroundings. The last crew member was the loader, who was placed alone on the right side of the vehicle. He was perhaps the most overburdened crew member. Beside his primary role of loading the main gun, he also operated the Fu 15 or 16 transmitter-receiver radio set. This equipment had an effective voice range of about 2 km. A 2 m long antenna rod was fitted on the superstructure. Beside the radio, the crew could use the Walther LP signal pistol to communicate with other vehicles. In addition, the loader was charged with using the machine gun placed on top of the vehicle and using the grenade throwing close defence weapon (if the vehicle had one).

StuG IV crew. Source: Worldwarphotos

The Armament

The main armament of the StuG IV was the 7.5 cm StuK (Sturmkanone – assault cannon) 40 L/48. This gun was developed by Rheinmetall-Borsig especially for the StuG III and was, in essence, a modified 7.5 cm PaK 40 anti-tank gun. The length of the barrel was 3.6 m and had 32 grooves, each 7.8 mm deep and 6.05 mm wide. It had a semi-automatic breech, which means that, after firing, the spent cartridge would be self-ejected, thus increasing the overall firing rate. It was fired electrically.

This gun had a muzzle velocity of 790 m/s. The armor-piercing (Pz.Gr.39) round could penetrate 85 mm of armor (sloped at 30°) at 1 km. The maximum range of the high-explosive rounds was 3.3 km while, for armor-piercing, 1.4 to 2.3 km, depending on the type used. The gunner used the ‘Selbstfahrlafetten Zielfernrohr Sfl.Z.F.1a’ gun sight to acquire targets. This sight had a magnification of x5 and a field view of 8°.

The elevation of this gun went from –6° to +20° (or –5° to +15° depending on the source), while the traverse was 10° (or 20°, depending on the source) to both sides. The ammunition load, depending on the source, consisted of 61 to 63 rounds. The ammunition was stored in holding bins located mostly on the right side of the vehicle, with some placed under the gun or to the back. Krupp specially designed ammunition box containers that were to hold 8 rounds. These could be used on the StuG IV or Panzer IV tanks without problems.

While, initially, the gun was locked at a traverse angle of 0° during driving, this would be changed to 12° later on. The main reason why this was done was to provide the driver with a better view to his right during driving. In addition, a frontal travel lock would be added to a number of vehicles during production.

Behind the gun breach, a small metal shield was placed to provide protection for the gunner. In addition, a shell sack was added to the rear of the gun, which caught spent cartridges. While, initially, the first produced StuG IVs used the earlier box type mantle, this would be replaced by the new cast Saukopfblende (sow’s head mantle), generally known simply as Saukopf.

The dismounted 7.5 cm StuK 40 L/48 gun. Source: Walter J. Spielberger Sturmgeschütz and its Variants

The StuG IV’s secondary armament consisted of one (or two) 7.92 mm MG 34/42 machine guns with 500-600 rounds of ammunition. The MG was not fired from inside the vehicle, but instead was mounted with a protective shield on the superstructure’s top, on the right side. This protective shield could be folded down if needed. Additionally, there were also two different mounting brackets for the MG, depending on if it was used against ground or air targets.

The raised protective machine gun shield is clearly visible in this photograph. Source: worldwarphotos

Some vehicles were equipped with the Rundumfeuer machine gun mount that was operated from inside the vehicle. This mount provided an all-around firing arc. In addition, the operator did not have to expose himself to fire when he was using the machine gun. However, he still needed to go outside to manually load the machine gun. The installation of this machine gun required some changes to the loader’s escape hatch (it had to be rotated at a 90 degree) before being fit to the vehicle. The machine gun was protected by two small angled shields.

Some vehicles received the Rundumfeuer machine gun mount. With this mount, the machine gun operator could fire it without exposing himself to enemy return fire. Source: Pinterest

It is also mentioned that, on rare occasions, some vehicles did not receive the machine guns and were forced to use only high-explosive rounds against enemy infantry, while some vehicles received a coaxial machine gun that was fired by the gunner. The machine gun was fired through a hole that was cut in the gun mantle. This modification was implemented only from June to October 1944 and it is not clear how many vehicles were actually equipped with this machine gun configuration.

Smaller numbers of StuG IVs were equipped with the Nahverteidigungswaffe (close-quarters defense weapon). In essence, this was a close-range grenade thrower that was to be used against infantry. Due to shortages of this weapon, mass use on the StuG IV was not possible. The Nahverteidigungswaffe was placed in front of the loader’s escape hatch. When not installed, the hole was covered by an armored cover.

The close-quarters defense weapon mount was placed in front of the original machine gun mount (the gun itself is missing) on the vehicle superstructure’s top right side. Due to production problems, this weapon was not a common sight in the StuG IV vehicles. Also note that this vehicle had the Rundumfeuer machine gun mount, the installation of which necessitated the redesign of the loader hatch door, which now opened to the side (instead of the original forward and back). Source: worldwarphotos
A close-up view of the Nahverteidigungswaffe (Note that this particular one was used on the Panther tank) Source: S. J. Zaloga Bazooka Vs. Panzer IV

Besides all these, the crews also had their own personal weapons for protection. This usually consisted of one or two 9 mm MP 40 submachine guns and sometimes even a 7.92 mm MP 44 assault rifle.

Distribution to units

The StuG IVs were used to equip various German formations. They were used to supplement assault gun units equipped with StuG IIIs. Which precise assault gun units received the new StuG IV is difficult to pinpoint, as the German documents do not make a distinction between the Panzer III and IV-based vehicles. The first produced StuG IVs were given to the 311th StuG Brigade which operated on the Eastern Front.

By the later stages of the war, German Infantry Divisions were supplemented by a Panzer Jäger Abteilung that contained a company of the towed 7.5 cm PaK 40 guns (or self-propelled versions, if any was available) and one company of 14 assault vehicles. As the StuG IV became available in sufficient numbers, these were also allocated to Infantry Divisions. During 1944, the number of assault vehicles was reduced to only 10.

Other units, such as Panzer, Volksgrenadier, and Panzergrenadier Divisions also received a number of these vehicles. German Panzer Divisions in early 1943 were severely lacking tanks and, for temporary replacement purposes, StuG IIIs were used. By late 1944 and early 1945, for the same reasons, some Panzer Divisions were equipped with StuG IV vehicles as replacements for lost tanks, as there was nothing else available in sufficient numbers.

Lastly, during the summer of 1944, Waffen SS units received some 70 StuG IV vehicles. For example, the 17th SS Panzergrenadier Division, due to an insufficient number of tanks, was instead reinforced with 42 StuG IVs.


The StuG IV, similar to later better-armed StuG III vehicles, were highly effective anti-tank vehicles. For example, the 394th StuG Brigade, which had two StuG IV-equipped batteries, fought the Allies on the Western Front. On 6th August, elements of these units destroyed 26 Allied tanks. The commander of the 3rd Battery claimed to have destroyed six Sherman tanks in combat with his StuG IV.

The previously mentioned 17th SS Panzergrenadier Division, which had 42 StuG IVs, participated in the fighting against the Allies in France. In the following battle with the Allies, it was left with only 11 operational StuG IVs by early July 1944.

A destroyed StuG IV that belonged to the 17th SS Panzergrenadier Division in France, 1944. Source: Pinterest

At the start of October 1944, during the German defense of Aachen against the Allied forces, the 12th Volksgrenadier Division had 10 StuG IV vehicles. These would be reallocated to the 49th Infantry Division several days later. During the Allied attack on Aachen that started on 7th December, they came under fire from the StuG IV vehicles. While the German defenses were breached near Alsdorf, the Allies lost 2 tanks. These were destroyed by Feldwebel Peter Klimas (a veteran with 22 destroyed enemy tanks). The following day, the Germans made a counterattack toward Alsdorf, supported by 6 StuG IVs. During the following engagement, one was lost due to a breakdown, three were lost due to enemy fire and only two managed to reach Alsdorf. These two surviving StuG IV vehicles (one was commanded by Feldwebel Peter Klimas) engaged the Allied forces that held the town. While the German vehicles were heavily involved in the ensuing fighting, the Germans lacked support to retake the town and had to withdraw. While both StuG IVs survived the defense of the Allied soldiers, some even armed with bazookas, they were damaged and Feldwebel Peter Klimas was wounded by enemy rifle fire.

Larger numbers of StuG IVs would see service on the Eastern Front. Some of these were part of the 236th StuG Brigade that fought against Polish Forces in the area of Niesky at the very end of the war in Europe. Another example was the 912th StuG Brigade, which had 30 StuG IV vehicles, all of which were lost by May 1945. Unfortunately, the sources do not give more precise information about the StuG IV’s combat operations in the East.

A StuG IV somewhere in Ukraine, 1944. Source: J. Ledwoch Sturmgeschütz IV

The StuG IV also served in smaller numbers on other fronts, such as Italy or the Balkans during 1944 and 1945. One such unit was the 914th StuG Brigade. Interestingly, this particular unit was supplemented with over 30 Semovente 105/25 M43 Italian assault vehicles.

Some StuG IVs would also be deployed in Greece during 1944. Source: J. Ledwoch Sturmgeschütz IV

One of the last combat actions of the StuG IV was during the defense of Berlin and its surroundings from the Soviets. There were some 29 StuG IVs with the Heeresgruppe Mitte and 20 with Heeresgruppe Weichsel. On 10th April 1945, there were still some 282 StuG IVs available on all fronts. There were 219 on the Eastern Front, 40 in the West, some 16 in Italy, and 7 in Denmark and Norway.

Other Operators

By the end of the war, the Soviets had managed to capture an unknown number of StuG IV vehicles. These vehicles were part of the 912th StuG Brigade which was originally equipped with 30 StuG IV vehicles. At least one was possibly operated by the 366th Guards Heavy Self-Propelled Artillery Regiment during the end of the war in Hungary.

A StuG IV operated by the Soviet Forces during 1945. Source: J. Ledwoch Sturmgeschütz IV

According to B. B. Dumitrijević and D. Savić (Oklopne jedinice na Jugoslovenskom ratištu 1941-1945), some StuG IVs were captured by Yugoslav Partisans and were used for a short time after the war. Their final fate is unknown as none were preserved, and they were probably scrapped.


While, officially, there were no sub-versions of the StuG IV, there were still at least two adaptations of it for other roles. One of these consisted of a StuG IV (minus the weapons) that was equipped with a large fixed dozer blade. This vehicle, named in some sources as the Räumschaufel Panzer StuG IV, was to be used for helping rebuild bombed German cities during the war, by clearing up the remains of destroyed buildings. It is unclear how many were used for this role, but unlikely more than a few. The second version was probably a field conversion, possibly used as an ammunition carried vehicle. Its main gun was removed for some reason (possibly damaged) and replaced with a simple armored shield. How many besides the one photographed were converted is not known.

The StuG IV equipped with the large dozer blade. Source:
Possibly an ammunition supply vehicle field conversion. Source: Pinterest

Surviving vehicles

Despite over 1,000 vehicles being built, today, only a few StuG IVs exist. Two can be seen in Poland at the Armored Weapons Museum in Poznan and White Eagle Museum in the Skarżysko-Kamienna. One more is in the Russian Kubinka Museum. The last vehicle can be found at the Australian Armor and Artillery Museum.

A StuG IV located at the Armored Weapons Museum in Poznan, Poland. Source: Wiki


Despite having been designed as a temporary replacement for its StuG III cousin, the StuG IV was actually produced up to the war’s end. While the Germans also fielded the Jagdpanzer IV anti-tank vehicle also based on the Panzer IV, the StuG IV was much easier and cheaper to produce. It was, in general, a good design with low height, solid armor protection, and a good gun. The downsides of this vehicle were that it was not produced in sufficient numbers and was often used in lieu of other vehicles for roles it was not meant for.

StuG IV, Ukraine, 1943
Sd.Kfz.167 in Ukraine, December 1943.
StuG IV, Ukraine, 1944
StuG IV in Ukraine, early 1944.
StuG IV, Russia
Unknown unit with Schurzen, Russia, summer 1944.
StuG IV with Schurzen
Unknown unit with space armor, Russia, 1944.
StuG IV, Eastern Prussia
StuG IV in Eastern Prussia, September 1944.
StuG IV, Germany
Late production StuG IV in “ambush camouflage”, Germany, April 1945.


Weight 25.9 tonnes
Dimensions Length 6.7 m, Width 2.95 m, Height 2.2 m
Crew 4 (Commander, Gunner, Loader, and Driver)
Propulsion Maybach HL 120 265 HP @ 2600 rpm
Speed (road/off-road) 38 km/h, 15 km/h
Range (road/off-road) 220 km, 130 km/h
Primary Armament 7.5 cm StuK 40
Secondary Armament One 7.92 mm MG 34
Elevation -6° to +20°
Armor 10-80 mm
Total Built 1,141-1,500


WW2 German Assault Guns

38 cm RW61 auf Sturmmörser Tiger ‘Sturmtiger’

German Reich (1944)
Assault Gun – 18 Built

Of all of the heavy tank projects from Germany in WW2, one vehicle stands out as something very different from the others and drew significant curiosity from the Allies when they first encountered it. A vehicle combining the armor of a heavy tank with a weapon never fitted to an armored fighting vehicle before, a 38 cm mortar. This incredible vehicle was developed for a specific purpose, urban combat. In such a situation, a huge shell could demolish whole buildings and defensive structures. It could deliver a huge explosive shell at close quarters or be used for long range shelling of an enemy position. That vehicle was the German Sturmtiger.
The origins of the Sturmtiger, or, more correctly, the ‘38cm RW61 auf Sturmmörser Tiger’, started with a call from the German Army (Heer) for a heavy howitzer specifically to help in urban combat, where a well-defended building could hold up an attack or otherwise be resilient against even ‘normal’ caliber artillery fire. What was needed was a gun capable of firing a large explosive shell both directly and indirectly and to have it mounted on a heavily protected chassis. This call was put into reality by Hitler on 5th August 1943, following the failure of other ideas for high-angle guns mounted on tank chassis.

Prototype to production

Despite Hitler’s order to develop a vehicle being issued in August 1943, only one prototype was initially ordered, possibly indicating how much confidence there actually was for such a weapon. Nonetheless, a vehicle was put together based on the chassis of a Tiger tank by the firm of Alkett in Spandau, using an armored superstructure built and assembled by the Brandenburg Iron Works (Brandenburger Eisenwerke) at Kirchmöser. The vehicle was ready and was shown to Hitler at the Ayrs Training Camp in East Prussia on 20th October 1943, an impressive turn-around time of under 3 months.
Despite the impressively rapid construction of a prototype, mass production was severely hampered by the slow rate of manufacturing of Tiger I tanks and was not due to start until mid-1944. Any production of Sturmtigers alongside the Tiger I would have impeded Tiger I production. Since priority was clearly given to the Tiger I tank, the Sturmtiger had to wait. In the meantime, the prototype was undergoing testing and trials.

Prototype Sturmtiger with rubber-tired road wheels. Note: this vehicle is in the possession of the Russian collection at Kubinka with steel-rimmed wheels and the steel counterbalance on the muzzle of the mortar – two later modifications, although it retains the uparmored lower front hull. Source Spielberger. The top image has been colorized by Jaycee ‘Amazing Ace’ Davis.
By May 1944, the Sturmtiger prototype had been kept busy with trials and firing tests for the development of range tables, but production had still not started and the concept was likely to be scrapped. Rather than ditch the idea though, Hitler ordered that, instead of interrupting the production of the Tiger I, the Sturmtigers would be built on the chassis of Tiger I tanks which had already been in action and suffered serious damage. These were being sent back to the factory for rebuilding rather than just for repair. Twelve Sturmtiger units were to be prepared. A Tiger I cost RM250,800 (Reichsmarks) each to build, but as these Sturmtigers were made from rebuilds, it is not possible to calculate the cost of the rebuilding of each hull as each vehicle used had suffered a different amount of the damage. Even so, the cost of building a Sturmtiger was estimated at RM53,000, which, if added to the RM250,000, means that each one constituted an investment of over RM300,000 (approximately US$4,255,264 in 2015 values). This was an enormous sum of money considering it cost just RM117,100 (approximately US$1,660,971 in 2015 values) for a Panther tank.*
*RM to US$ exchange values conducted using Historical Statistics
Twelve Sturmtigers were built which, with the prototype, makes thirteen Sturmtigers finished by the end of September 1944. Five more were ordered by Hitler on 23rd September 1944. Those additional five vehicles were all finished by the end of December 1944, followed by orders for more, although these were never produced. In total, 18 Sturmtigers were built.

Running gear

The running gear for the Sturmtiger was identical to that of the Tiger I with the exception that only the prototype had the rubber-tired wheels. The production Sturmtigers were supposed to be fitted with the rubber-tired road wheels to help manage the additional 8-tonne load of the Sturmtiger over that of the Tiger I, but they all are seen with the steel-rimmed wheels common to late Tigers. The rubber-tired wheels are one of the identification features of the original prototype Sturmtiger, even though even these were later changed to the steel-rimmed wheels. The engine remained the same as on the Tiger I, a Maybach HL 230 TRM P45 and, with the additional weight, the Sturmtiger was markedly slower and less maneuverable than the Tiger I. If a later production damaged Tiger I tank was used to build a Sturmtiger it would be powered by the more powerful Maybach HL 230 TRM P45 V-12 700 hp petrol engine.

Armor and Optics

The lower hull of the Sturmtiger was that of the Tiger I and remained unchanged. Nominally, the armor on the Tiger I consisted of a lower front hull plate 100 mm thick, a short glacis 60 mm thick and a reclined driver’s plate 100 mm thick. The sides were a uniform 80 mm thick and vertical on both lower and upper section, and 80 mm thick on the back. Due to manufacturing tolerance allowance of 0 to +5%, many of these plates ended up being recorded as slightly thicker i.e. 102 mm instead of 100 mm.

For the Sturmtiger, the turret was removed, as was the roof of the hull over the fighting compartment. Further, the driver’s plate was mostly gone, with the top half of it cut-off across the full width. Replacing all of this was a large flat-sided box containing all the crew and the main gun. The front of this box was made from a single slab of armor plate 150 mm thick angled back at 45 degrees which extended down to a point about halfway along the length of the glacis. It was held to the front of the hull by two substantial armor plates bolted over the joint. In the front of the plate was a large, armored ball-mount 69 mm thick for the 38 cm mortar and a small ball-mount for the forward-firing M.G.34 machine gun. The gun and mount were also protected by a 150 mm thick mantlet. On the left of the gun was a rectangular opening which took the aiming telescope and, below this, a pair of small visors under a small cowl were placed for the driver. The sides and rear were made from slabs of armor 80 mm thick but angled inwards towards the roof, which was 40 mm thick. On the prototype, an additional 50 mm thick slab of armor was bolted to the lower front hull of the Sturmtiger, but this feature was dropped from production vehicles, presumably to save weight.

Armor scheme for the Sturmtiger which omits the remnants of the bottom half of the driver’s plate and top part of the glacis which would lie just behind the bottom edge of the 150 mm thick front plate on the Sturmtiger. This scheme also omits the armored mantlet around the gun barrel. Source: Wikipedia

View of the driver’s station at the front-left of the Sturmtiger clearly shows both his vision optics but also that the original glacis was left intact and the original driver’s plate was simply cut off lengthwise for the new front plate. Source: Schneider

Seen from the outside, it is clear that the new front plate significantly overlaps the old armor on the front of the Tiger. The thick block of armor on the corner is there to cover the overlap between the new casemate and the hull. The bolts on the side indicate a reinforcing plate added on the inside joining the two sections together. Source: Schneider
Sighting for the mortar was by means of a Kugeloptik ZF3 x8 sight using the aperture to the left of the main gun and a KgZF2 sight. Other features included the pistol ports on both sides, perhaps more useful for aiding vision than the original intention for them.

Overhead view of a Sturmtiger showing the large rectangular roof hatch used for reloading. Source: The Tank Museum, Bovington

The gun

Originally, the request from the Army called for a 210 mm howitzer but, with no suitable options, they turned to Rheinmetall-Borsig for their Raketenwerfer 61 L/5.4 (Gerat 562 – Sturmmörserwagen 606/4). The gun itself existed in two iterations at the time. One, the R.aG 43 (Raketenabschussgerät 43), was a ship-mounted anti-aircraft weapon used for firing a cable-spooled parachute-anchor creating a hazard for aircraft. The second, the RTG38 (Raketen Tauch Geschoss 38), was a land-based system. Both systems had been made by Rheinmetall-Borsig, in Dusseldorf, but had been designed by MOHRA Gerätebau Aktiengesellschaft Bautsch of Ostsudeten. It was the RTG38 which formed the basis of the weapon in the Sturmtiger. With a range of 3,000 m, it had originally been planned for use in coastal installations by the Kriegsmarine firing depth-charges against submarines. For use in a vehicle, it was to find use as a demolition gun and had to be modified for that role. This modification work was carried out by Rheinmetall at their Sommerda works.
In its coastal defense role against submarines, it was not an effective weapon, and only 12 were made, of which 3 were tested in 4th April 1944 at Trondheimsfjord, Norway. The result was that problems were identified with the fuzing and the rounds failed to achieve the ranges (up to 3,000 m) desired. A second test firing, held on 20th April 1944, revealed an 18% failure rate, likely due to problems encountered when the shell hit the water. Instead, the weapon was selected for use against surface targets and they were based in positions at Fanø Island, Denmark (1 weapon based on the Marine Küsten Batterie Gneisenau) and at batteries at Alta, Agdenes, and Trondheim in Norway (unknown numbers). Two of these weapons are preserved in museums in Copenhagen (Denmark), and Tromsø (Norway), respectively.

R.aG43 at the Tøjhusmuseet in Copenhagen, Denmark, marked ‘bwo 38cm Nr.10’ (left). Unconfirmed RTG38 (possibly a modified RaG43) at the Narvik War Museum (right), the example in Norway appears unmarked or illegible. Source: Massimo Foto on Landships (left) and Yetdark on Flickr (right) Further research on these guns is needed.

Believed to be a R.aG43 on a land mount for coastal defence in Denmark or Norway. Source:
Modified for use in a vehicle, the recoil from the modified rocket-mortar was enormous, about 40-tonnes, and this meant that only a heavy chassis could be used to mount the gun. The only suitable vehicle in Autumn 1943 was the Tiger I.
Some of the gun barrels were modified during production with a heavy steel ring around the muzzle as a counterweight to make elevation easier but, other than the mounting, the gun was effectively the same principle as before. The shells for the weapon were extremely heavy, far too heavy for a man to load manually, at 330 kg each. As a result, each of them had to be carried by means of a ceiling-mounted trolley from their rack to a roller-mounted tray at the breech. Once on the tray, four soldiers could then push it into the breech to load it. The whole process took 10 minutes per shot from loading, aiming, elevating to firing.

Breach of the RW61 with shell absent (left) and being loaded, providing a good view of the vents on the bottom of each shell (right). Source: Schneider (left), Navweaps (right)
The rounds were huge and only 12 rounds could be carried internally on the 6 racks provided, stacked three high and two deep on each side. No special resupply vehicle was provided to carry additional shells but additional shells could be carried in trucks by the unit, which would allow the Sturmtiger to be reloaded having withdrawn from combat. Reloading of these huge shells was carried out by means of a roof-mounted (temporary) crane which was erected on the back of the cab and lowered shells through a removable hatch in the roof of the casemate and down onto the stowage racks.

Reloading process for the Sturmtiger was laborious but straightforward. 1) Unpacking the shell after rolling it into place on a pair of wooden rails. 2) Attaching the clamp for the crane to lift the shell. 3) Hoisting the shell up with crew to keep it steady. 4) Lowering the shell through the roof hatch to be racked inside. Source: Schneider.
Rebuilt for the Wehrmacht, the mortar was named the 38cm Rocket Launcher RW61 (RW – Raketenwerfer) and fired two types of shell, an explosive shell (Raketen Sprenggranate 4581) for general use, and a hollow-charge shell (Raketen Hohlladungsgranate 4592) specifically for targeting reinforced concrete structures, as the warhead could penetrate up to 2.5 m of reinforced concrete. The range, however, was dependent on temperature ranging from a maximum range of 4,200m at -40 C to 5,900m at 50 C, and 6,650m at 15 C. This very large difference in shell performance was because it used a combustion process of propellant as the rocket was fired which was slower-burning in cold weather – the result were very lengthy range/temperature tables for the crew to use in order to accurately lay the gun. Not only was the range affected by temperature but so was shell flight and accuracy. To account for these discrepancies temperature measurement was important in the vehicle and the crew was provided with details range tables listing the elevation, range and temperature in order to maintain accuracy. The minimum range for firing from the tables was just 50 m.
Each shell came in two parts: a case about 550 mm long holding 40.1 kg of diglycol powder (rod form) as the propellant, and the H.E. shell itself carrying 122.5 kg of Amatol 50/50 high-explosive (with six P.E.T.N. pellets acting as the exploders), forming a complete 1,489 mm long (1,440 mm shell and case plus 49 mm fuze) long. Each shell used the same Treibsatz 4581 rocket motor and each case was thin-walled with 32 venturi holes in the bottom to vent out the propellant gases. The venturi holes were angled at 14 degrees to the axis of the rocket, and together with the splines which went into the rifling of the gun caused the shell to rotate clockwise in flight for stability.
Following examination of the records at the Sommerda factories in 1945, it was determined that there were two types of fuzes produced for the Sturmtiger shells. The first was the A.Z.KM 8m.r. (or K.N.9) direct action and delay fuze (percussion fuze with an optional delay of 0.12 seconds) for the High Explosive Shell (4581), and the A.Z.KM.10 hollow charge fuze (nose percussion with no delay) for the hollow charge shell (4592). The delay fuse was found to sometimes malfunction when striking a target at an angle of less than 14 degrees requiring multiple impacts before it would function. When striking a hard target at a steep angle, therefore, the round could actually break up without detonating so the delay on the fuze was not used when firing against hard targets or when the ground was very hard.

38cm Raketen-Sprenggranate 4581 (High Explosive) (left) and 38cm Raketen-Hohlladungsgranate 4592 (right). Source: War Office(UK) 1945 (left) and Navweaps (right)

The disassembled 38cm Raketen-Sprenggranate 4581 (High Explosive) shell with the HE containing section at the front. Source: US Army Catalog of Enemy Ordnance
Elevation was by means of a crank at the left of the mounting and could elevate the gun between 0 and 85 degrees with a traverse-crank over the barrel controlling side-to-side movement. This traverse movement allowed firing up to 10 degrees each way.
The barrel was radically different in design to other guns, with a cast outer body and a liner inside made from steel about 12 mm thick. Into this liner were cut nine rifling grooves into which splines on the rocket would sit and then rotate during firing. During firing, the gases produced were vented through the gap between the inner barrel and the outer barrel sheath. The two pieces of the barrel were held together at the breech and muzzle with steel rings and by drilling 32 holes the gases from combustion could be vented forwards keeping the gas out of the crew space and reducing the recoil of the gun.

Sturmtiger, Warsaw Uprising
Dunkelgelb-camouflaged Sturmtiger used during the Warsaw Uprising.

Sturmtiger, Reichswald
Sturmtiger in a late-war “ambush” camouflage, Reichswald, Germany, February-March 1945.

Sturmtiger receiving ammo
Illustration of a Sturmtiger receiving ammo. This was a tough job, in which the whole crew was involved due to the sheer weight of the shells.


Sixteen of the eighteen Sturmtigers were issued to Sturmmorser Companies 1000, 1001, and 1002 for the defense of the German homeland in 1944. These companies, known as Panzer Sturmmörser Kompanien (Pz.Stu.Mör.Kp.), were originally intended to be issued with 14 vehicles each but, in the end, unit 1000 received just 4 Sturmtigers and 1001 and 1002 received 6 each (16 vehicles). In unit organization, Sturmtigers were paired up, with two vehicles forming a Zug (Platoon).
Pz.Stu.Mör.Kp.1000 was formed from two Zugs for a total of 4 vehicles. It was officially formed on 13th August 1944 and the day after formation, the unit was ordered to form part of Heeresgruppe Mitte (Army Group Mitte) and a force of two vehicles (with personnel from Alkett) was sent (15th to 18th August) to quell the Warsaw Uprising. After this, there were plans to send them to Bratislava (Pressburg) to quell the September 1944 Slovak Uprising, but that rebellion petered out before the unit was sent.
The second Zug of two Sturmtigers was sent to France by the end of August 1944. The first Zug was then sent to Hungary, where it was attached to Panzer-Brigade 109 by the middle of September 1944. By the end of October, the second Zug was withdrawn back to Warsaw and then sent back to Sennelager in Germany for refitting. In December 1944, Pz.Stu.Mör.Kp.1000 had been attached to 15th Armee as part of 6th SS-Panzer-Armee but only had 3 operational vehicles in time for Operation Wacht Am Rhein (Watch on the Rhine) in the Ardennes. As a result of problems with transportation though, these vehicles never reached the starting points for the operation and took no part in the offensive. By the end of January 1945, this unit had been redesignated as an Artillery unit and the strength had been increased to 3 Zugs comprising 6 vehicles.
A record of the use of the Sturmtiger by this unit in combat comes from the unit history for the US 113th Cavalry Group, which recorded that, on 5th February 1945, they were shelled by ten ‘rocket-type’ projectiles which produced huge explosions, followed by two more rounds against the town of Pier. This is believed to be an attack by Pz.St.Mör.Kp.1000 and, when the 113th Cavalry captured the town of Bedburg, they found an abandoned Sturmtiger which is what they ascribed that shelling by rocket-projectiles too. The 737th US Tank Battalion, during actions around the town of Menden, also reported being attacked by a Sturmtiger thought to be from this unit.

Still from a video of the Sturmtiger in combat 1944. Source: Spielberger
Pz.St.Mör.Kp.1001 did not fare much better. Officially formed on 23rd September 1944, the first Zug was not ready until the end of September, followed in the first week of October by the second Zug, but was not combat ready until the end of the month. On 10th November 1944, both Zugs were sent to Oberbefehlshaber West. Just like Pz.St.Mör.Kp.1000, this unit was also deployed for Operation Wacht Am Rhein (Watch on the Rhine) and was also assigned to 15th Armee as a part of the 6th SS-Panzer Armee, again with just 3 vehicles. Unlike Pz.St.Mör.Kp.1000 which did not reach its starting point for the operation, the 3 vehicles of Pz.St.Mör.Kp.1001 did get to the start point. The Operation had called for (amongst other things), the capture of the Belgian city of Liege in the Northern sector of operations. It was for this task that both Pz.St.Mör.Kp.1000 and 1001 were originally intended. As it was, the German forces never got close to Liege and only Pz.St.Mör.Kp.1001 even got to the theatre. Pz.St.Mör.Kp.1000 did not see action during the operation, but Pz.St.Mör.Kp.1001 did, albeit not for its original target of Liege.
Instead, Pz.St.Mör.Kp.1001 saw action around Duren and Euskirchen just before the New Year, covering the retreat of German forces. Just like Pz.St.Mör.Kp.1000, Pz.St.Mör.Kp.1001 was reassigned and, by the end of January, along with Pz.St.Mör.Kp.1000, was redesignated as an Artillery unit with a strength set to be 3 Zugs (6 vehicles).
During action at Duren on 26th February 1945, one Sturmtiger was knocked out when the driver got the vehicle stuck in a ditch along the roadside during the withdrawal from the town. Immobilised, it was shot at least three times in the rear by a Sherman tank of C Company, 743rd Tank Battalion, which was supporting the attack by the 117th Infantry, part of the US 30th Division. With the 80 mm thick rear armor penetrated and the vehicle stuck, the crew bailed out, all had survived these multiple strikes but one crew member was shot and killed by the infantry as they fled. This vehicle was recovered in March 1945 by the 464th Ordnance Evacuation Company and shipped to Great Britain for evaluation. The vehicle was later scrapped but the gun remains on display at the Tank Museum, Bovington.

This Sturmtiger of Pz.St.Mör.Kp.1001, immobilized in a ditch, was hit repeatedly by a Sherman of 743rd Tank Battalion causing the crew to evacuate. Source: Zaloga
The final action of Pz.St.Mör.Kp.1001 took place in the defense of Drohlshagen to the East of Bonn in Spring 1945. Shortly after, with just 3 Sturmtigers left and with serious problems with maintenance, the vehicles were destroyed by the crews prior to capture.
The final company, Pz.St.Mör.Kp.1002, was formed in October 1944 and was sent, in December 1944, to be a part of Oberbefehlshaber West. Just like Pz.St.Mör.Kp.1000 and 1001, it was redesignated as an Artillery unit at the end of January 1945 and was supposed to be increased to a strength of 3 Zugs (6 vehicles). Its combat history started at the battle of the Reichswald followed, in March 1945, by action at Kirschellen. Further actions followed at Polsum, Marl, and Datteln. By the middle of March 1945, the unit had exhausted its supplies and the last two vehicles were blown up by their crews.

Sturmtiger firing one of its 38cm rockets. Source: Spielberger


The Sturmtiger was, in one way, a very clever way of reusing a damaged Tiger-tank hull. The hulls were expensive to make and anything that kept the investment of the Reich in service against the Allies was a good move resource-wise. The logic of the weapon system though is less clear, as by the time they were built they effectively had no role. These might have found in a role in a battle for a city such as at Stalingrad, but that was over well before the first Sturmtiger ever saw service.
The combination of a unique weapons system with very limited utility, on a heavily armored platform was not really what Germany was needing at the time. Better use might have been to consider simply mounting an effective anti-tank gun into that casemate instead, as vehicles like the StuG III had proven their utility as cheap and effective tank destroyers. Even a short-barrelled howitzer of some description might have found a role for infantry support and both ideas would surely have been a better use of those valuable hulls. As a vehicle for assaulting a heavily urban area, when by this time the urban fighting was defensive, it simply had little use. This is proven out by the actual combat history of the Sturmtiger, where it simply failed to find a clear role in the later war, an interesting but essentially useless weapon considering the resources poured into it.

Surviving Vehicles and Guns

Chassis Number 250174 – Deutsches Panzermuseum in Munster (German Tank Museum)
Chassis Number 250043 – Patriot Park, Kubinka, Russia
Sturmtiger 380mm Mortar (no vehicle) – The Tank Museum, Bovington, UK
R.aG43 – Tøjhusmuseet, Copenhagen, Denmark
Unconfirmed RTG38 (possibly a modified RaG43) – Narvik War Museum, Norway

Surviving Sturmtiger at the Deutsches Panzermuseum. Photo: wikimedia

Sturmtiger specifications

Dimensions 6.28 x 3.57 x 2.85 m
Total weight, battle ready 65 tonnes
Crew 5 (Commander, Driver, Gunner, 2 Loaders)
Propulsion Maybach HL 210 TRM P45 21-litre V-12 petrol engine producing 650 hp at 3000 rpm or
Maybach HL 230 TRM P45 V-12 700 hp petrol engine (later production vehicles)
Speed (road) 40 km/h
Armament 38cm RW61 L/5.4 (12 rounds)
MG 34 machine-gun
Armor Casemate front: 150mm @ 47 deg.
Sides and rear: 82mm @ 20 deg.
Roof 40mm @ 0 deg.
Prototype had additional 50mm plate on the lower front of the hull
For information about abbreviations check the Lexical Index


Chamberlain, P., Doyle, H., Jentz, T. (Ed.). (1993). Encyclopedia of German Tank of World War Two. Arms and Armour Press, London, England.
Culler, B. (1989). Tiger in Action. Squadron/Signal Publications, TX, USA
Datenblätter für Heeres Waffen Fahrzeuge Gerät W127. (1976).
Schneider, W. (1986). Elefant, Jagdtiger, Sturmtiger. Schiffer Publishing, PA, USA
US Chief of Ordnance. (1945). Catalog of Enemy Ordnance. US Army.
Willey, D., Hayton,M., Vase, S. (2015). Tiger Tank: Owners’ Workshop Manual. Haynes Publishing Group, UK
Zaloga, S. (2012). Armored Victory 1945. Stackpole Books, PA, USA
War Office. (4th April 1945). Technical Intelligence Summary No.171.

Video of the Sturmtiger featuring footage of it firing

Tanks Encyclopedia Magazine, #2

Tanks Encyclopedia Magazine, #2

The second issue of the Tank Encyclopedia magazine covers the fascinating history of armored fighting vehicles from their beginnings before the First World War up to this day! This issue covers vehicles such as the awe-inspiring rocket-firing German Sturmtiger, the Soviet SMK Heavy Tank, the construction of a replica Italian FIAT 2000 heavy tank and many more. It also contains a modeling section and a feature article from our friends at Plane Encyclopedia cover the Arado Ar 233 amphibious transport plane! All the articles are well researched by our excellent team of writers and are accompanied by beautiful illustrations and period photos. If you love tanks, this is the magazine for you!
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WW2 German Assault Guns

Sturmpanzer IV Brummbär

German Reich (1943)
Heavy Assault Gun – 303-316 Built

Development of the Sd.Kfz.166

In 1942, Albert Speer placed an order for a howitzer mounted on a tank chassis to keep up with the Panzer Divisions. Alkett received the order to design the new vehicle, which would be known as the Sd.Kfz.166, Sturmpanzer, or Sturmpanzer 43. Although commonly referred to as the Brummbär, this was the nickname given to the Sturmpanzer 43 by Allied intelligence, not by the Germans. They referred to it casually as the Stupa 43.

Hello dear reader! This article is in need of some care and attention and may contain errors or inaccuracies. If you spot anything out of place, please let us know!


The chassis was the one of the reliable, mass-produced Panzer IV. Above it, Alkett fitted a massive 15 cm (5.9 in) Sturmhaubitze (StuH) 43 L/12 developed by Škoda, which had common ammunition with the standard siG 33 howitzer in German service. 38 rounds with their separate propellant cartridges were carried, stored in the casemate and the hull. However, these massive rounds had a combined weight of 46 kg (38 kg/84 lb for the High Explosive shell itself and 8 kg/18 lb for its propellant cartridge), which made manual loading especially arduous on some elevations. The gunner set up the trajectory and aimed the gun using a Sfl.Zf. 1a sight.
The howitzer was protected by a casemate with sloped sides and thick armor plates. Indeed, this thickness was 100 mm (3.93 in) at a 40° angle on the front, 40 mm/12° (1.57 in) for the front hull, 50 mm/15° (1.97 in) for the side superstructure, 30 mm (1.18 in) for the side of the hull and 30 mm /25°/0° (1.18 in) for the rear of the casemate and 20 mm /10° (0.79 in) for the back of the hull. The top and bottom were protected by 10 mm (0.39 in) of armor at 90°. Outside the main howitzer, a single MG 34 machine gun could be fastened to the open gunner’s hatch, in the same way as for the Sturmgeschütz III Ausf.G. In addition, early vehicles carried a MP 40 sub-machine gun intended to be fired through the two firing ports on each side of the superstructure.
The driver was located forward, slightly in front of the casemate, and was given the Tiger I Fahrersehklappe 80 sight. Ventilation of the casemate’s fumes and heat was provided by natural convection, exiting through two armored covers at the back of the roof. By the time these vehicles were ready, spaced armor became the norm and Schürzen plates were factory-fitted. The first production vehicles proved their superstructure was way too heavy for the chassis, and experienced breakdowns of suspension elements or the transmission. The second series corrected this issue with a newly shaped, lighter casemate. The decision was taken in October 1943 and after the redesign, 800 kg (1,800 lb) of steel were spared, including from the gun mount itself on the third series. This new series was named StuH 43/1. Also, the Zimmerit anti-magnetic coating was factory-applied until September 1944.

Production & variants

Sources conflict as to how many were built, either 306 or 313. There were four series built as follows, all using variants of the Panzer IV chassis.
– Series 1: April 1943 60 built by Vienna Arsenal, with 52 using Panzer IV Ausf.G and 8 using rebuilt Ausf.E chassis.
– Series 2: December 1943-March 1944 60 built at the Vienna Arsenal using Ausf.J chassis.
– Series 3: March-June 1944 Built at Vienna Arsenal.
– Series 4: June 1944-March 1945 Built at the Deutsche Eisenwerke on Ausf.J chassis.
Because of the weight of the gun, there were problems with the suspension of the Brummbär. With Series 4 a new, lighter gun eased the problem considerably; in addition, a MG 34 was mounted for close defense. Previous models had a MG 34 mounted on the commander’s cupola.
The only variant of the Brummbär was a command vehicle, Befehlsturmpanzer IV. It had extra radio capacity. Krupp also built one prototype of a proposed Jagdpanzer IV with a 8.8 cm Pak 43 L/71.

The Sturmpanzer IV in action

The Brummbär primarily saw service in 4 battalions, Sturmpanzer-Abteilungen 216, 217, 218, and 219.
Sturmpanzer-Abteilung 216 first saw action at Kursk, when it formed the 4th battalion of Panzerjaeger 656, where it got as far as Ponyri. Afterwards, it withdrew to defensive positions to repel the Soviet offensive around Orel. As an independent battalion, it next saw service at Anzio in Italy, and from then to the end of the war it withdrew north until the battalion was forced to destroy its remaining vehicles and surrender in the Po valley.
Sturmpanzer-Abteilung 218, raised in August 1944, fought against the Warsaw Uprising, then remained on the Eastern Front until destroyed in East Prussia, in April 1945.
Sturmpanzer-Abteilung 219 fought against the Soviets in the Budapest area. At least two companies of Brummbär-equipped units are known: Sturmpanzer -Kompanie z.d.V. 218 took part in crushing the Warsaw uprising, then incorporated into the Sturmpanzer Abteilungen noted above. Sturmpanzer-kompanie Z.B.V. 2.-/218 was transferred to the Paris area on August 20th 1944, nothing more is known of this unit.
During the battle of Normandy in the summer of 1944, short barrelled 15 cm Sturmpanzer IV ‘Brummbärs’ (Sd.Kfz.166) were deployed to assist in street fighting in the villages and deal with enemy units in fortified locations. They were part of the 217.Sturmpanzer-Abteilung (assault tank battalion). It was formed of three companies of fourteen Sturmpanzer IVs and three additional vehicles used by the command company.
On 24 June 1944 it was ordered to move from Grafenwöhr in Germany to Normandy. On 18 July 1944 the battalion reported that it had reached the area of Condé-sur-Noireau/Le Bény-Bocage and Vire in Normandy. Not all of the Sturmpanzer IVs had completed the journey. Some had suffered mechanical problems.
On 23 July 1944 the 2nd Company was attached to the 21.Panzer-Division. It reported it had eleven working vehicles with two being repaired. On 29 July 1944 it was transferred to the II.SS-Panzer-Division LAH and the next day reported that it now only had nine working vehicles with two in repair.
The 3rd Company had been attached to the II.SS-Panzer Korps. On 30 July 1944, the 3rd Company was transferred to the LXXIV Korps.
On 6 August 1944, Thirteen Sturmpanzer IVs from the 217.Sturmpanzer-Abteilung were reported to be supporting the 89.Infantry-Division. Things changed because on 9 August 1944 ten of these Sturmpanzer IVs were in action with the SS-Panzer-Divison Hitlerjugend on only one was left with the 89.Infanterie-Division.
Some wrecked Sturmpanzer IVs locations were noted following Operation Totalize 8/9th August around the Normandy village of Cintheaux on the Caen-Falaise main road. One was found 1.5 km north west of Cintheaux in the field south east of the junction of the D23 with the road, now track, called La Maisonnette by the cross roads. Two were found near each about 750 m south west of Cintheaux along a track that runs south west from the town limits sign on the D183. A fourth was reported in a field to the west of the D167 about 1 km south south west of Cintheaux.
On 10 August 1944, only five of the ten vehicles were reported in a working condition. The situation was the same the next day. On 11 August 1944 the 1st Company, 217.Sturmpanzer-Abteilung was reported attached to the 271.Infanterie-Division.
On 16 August 1944 the 217.Sturmpanzer-Abteilung reported that between 1 to 15 August 1944 the battalion had lost ten men killed, twelve were missing and thirty-five were wounded. Only seventeen Sturmpanzer IVs were combat ready. Fourteen were under repair and predicted to be ready in less than three weeks.
The Battalion’s remaining Sturmpanzer IVs continued to see action supporting the SS-Panzer-Divison Hitlerjugend and the 89.Infanterie-Division. Both units fought on the same front in Normandy.
Those that escaped the Falase pocket were reformed and saw action during the battle of the bulge, Ardennes offensive. It reached St. Vith, but got no further. The unit was finally captured in the Rhur pocket in April 1945.


Objective Falaise by Georges Bernage
Sturmpanzer-abteilung 216 by Attilios on Panzer-central, World War II German Army Research,, Achtung Panzer
The Sd.Kfz.166 Brummbär on Wikipedia
Sturmpanzer IV article


Dimensions (L-W-H) 5.9 m x 2.8 m x 2.52 m
(19ft 5in x 9ft 5in x 8ft 3in)
Total weight, battle ready 28.2 tons (62,170 lbs)
Armament 15 cm (5.9 in) StuH 43 L/12 (Series 1), StuH 43/1 L/12 (series 2-4) (38 rounds)
7.92 mm Machinengewehr 34 (external machine gun)
Armor 10 mm to 100 mm (0.39 – 3.93 in)
Crew 4-5 (commander, driver, gunner, 2 loaders)
Propulsion Maybach HL120TRM V-12 watercooled, gasoline, 300 bhp (221 kW)
Speed 40 km/h (25 mph) road, 24 km/h (15 mph) off-road
Suspension Leaf springs
Range 210 km (130 miles)
Total production Approx. 316

Sd.Kfz.166 Brummbär, July 1944, Normandy
Early Brummbär from the Sturmpanzer Abteilung 217, Caen area, Normandy, France, July 1944.
Sd.Kfz.166 Brummbär, Warsaw
Early Sd.Kfz.166 from the St.Pz.Abt.218 in Warsaw, August 1944.
Brummbär, Italy, 1944-45
Sturmpanzer Abteilung 216, Italy, fall 1944.
Sd.Kfz.166 Brummbär, Zimmerit
Late production Sd.Kfz.166 Brummbär with Zimmerit paste and metallic rim roadwheels, now preserved at the Saumur Museum.
Sd.Kfz.166 Brummbär, Schürzen, Germany, 1945
Late production Brummbär with the “ambush” type camouflage, Eastern Germany, 1945.


Brummbär at Saumur
Late type Brummbär at the Saumur tank museum, covered with Zimmerit.
Brummbär, front, Saumur museumBrumbär in Italy, Anzio-Nettuno area Brummbär, Deutsch Panzermuseum MünsterFront view of the BrummbärFront right view of the BrummbärBrummbär track detailBrummbär drivetrain detailBrummbär drivetrain detail - leftBrummbär, Aberdeen proving groundsBrummbär next to a Tiger in the Anzio-Nettuno area

Video about the Brummbär

Germans Tanks of ww2
Germans Tanks of ww2