StuG IV

The StuG IV was a German assault gun of the Second World War, built on the chassis of the Panzer IV medium tank and armed with the 7.5 cm StuK 40 gun. Introduced in late 1943 as a replacement for the StuG III, whose production was disrupted by Allied bombing, the StuG IV was built in about 1,100 examples between December 1943 and April 1945. The vehicle combined the StuG III’s casemate and gun with the Panzer IV’s chassis, engine and running gear, and it served as both an assault gun and a tank destroyer on the Eastern Front, in Italy and on the Western Front. Although it was built in smaller numbers than the StuG III, which was produced in about 10,000 examples, the StuG IV was an effective weapon in the last year of the war, when Germany needed every armoured fighting vehicle it could produce. Its low silhouette, its powerful gun and its use of a proven chassis made it a valuable addition to the German Army’s armoured forces, and it remained in service until the end of the war in May 1945.

1. Key Facts

Type	Assault gun / tank destroyer
Origin	Germany
In service	1943–1945
Number built	About 1,100–1,150
Crew	4 (commander, gunner, loader, driver)
Weight	About 23 tonnes
Armour	Up to 80 mm front, 30 mm sides
Main armament	7.5 cm StuK 40 L/48
Engine	Maybach HL 120 TRM, 12-cylinder petrol, 300 hp
Top speed	About 40 km/h on roads
Operators	Germany; also used by Finland, Romania and others in small numbers

2. Development

The Bombing of the StuG III Factory

The StuG IV was born out of necessity. The StuG III, Germany’s most-produced armoured fighting vehicle, was built by the Alkett company in Berlin, and in November 1943 the Alkett factory was heavily damaged by Allied bombing. Production of the StuG III fell sharply, and the German Army needed a replacement that could be built quickly using existing chassis and components. The Krupp company, which built the Panzer IV, proposed mounting the StuG III’s casemate and gun on a Panzer IV chassis, and the design was approved in November 1943. The first StuG IV was completed in December 1943, only a month after the proposal, and production began immediately at the Krupp-Grusonwerk in Magdeburg.

Krupp and Rapid Production

The StuG IV’s rapid development was possible because it used existing components: the Panzer IV chassis, engine and running gear from Krupp, and the StuG III’s casemate and 7.5 cm StuK 40 gun from Alkett. The casemate had to be modified to fit the Panzer IV chassis, which was wider and had a different layout from the Panzer III chassis, and the vehicle’s superstructure was redesigned to accommodate the change. The StuG IV entered production in December 1943, and about 1,100 examples were built by April 1945, when production ended as the war came to a close. The vehicle’s production was a testament to the German armoured vehicle industry’s ability to adapt quickly to disruption.

A Stopgap That Became a Standard

The StuG IV was originally intended as a stopgap, to replace the StuG III until the Alkett factory could be repaired and StuG III production resumed. In the event, the StuG IV became a standard vehicle in its own right, and it served alongside the StuG III for the rest of the war. The German Army valued the StuG IV for its use of the Panzer IV chassis, which was more widely available than the Panzer III chassis, and for its powerful gun and low silhouette. The vehicle’s production in over 1,100 examples made it one of the more numerous German armoured fighting vehicles of the last year of the war, though it was still far behind the StuG III in total numbers.

3. Design

Casemate and Armour

The StuG IV’s casemate was based on the StuG III’s, with 80 mm of frontal armour, 30 mm on the sides and 20 mm on the rear, and a low silhouette of about 2.2 metres high. The casemate was mounted on the Panzer IV chassis, which was wider than the Panzer III chassis, and the vehicle’s superstructure was slightly different from the StuG III’s, with a different roof layout and a commander’s cupola on the left side. The frontal armour was sloped, and the vehicle was protected by 5 mm Schürzen side skirts on many examples. The StuG IV’s low silhouette and thick frontal armour made it well suited to its role as an assault gun and tank destroyer, where it fought from ambush and from prepared positions.

Chassis and Running Gear

The StuG IV used the Panzer IV chassis with its four large road wheels, leaf-spring suspension and rear drive sprocket, and the Maybach HL 120 TRM engine of 300 hp. The chassis was reliable and well understood, and spare parts were shared with the Panzer IV, which was an advantage in the last year of the war. The vehicle’s weight, about 23 tonnes, was within the chassis’s capacity, and its top speed was about 40 km/h on roads and about 20 km/h cross-country. The StuG IV’s mobility was adequate for its role, though it was not a fast vehicle, and its range was about 210 km on roads. The chassis was, however, the vehicle’s main difference from the StuG III, and it gave the StuG IV a slightly different appearance and a different driving feel.

Crew and Interior Layout

The StuG IV had a crew of four: a driver at the front left, a gunner to the left of the gun, a loader to the right and a commander behind the gunner, with a cupola for observation. The crew worked in a cramped casemate, though the Panzer IV chassis gave slightly more room than the Panzer III chassis, and the vehicle’s interior was similar to the StuG III’s. Ammunition stowage was about 63 rounds for the 7.5 cm gun, and the vehicle carried a single MG 42 machine gun on the roof for close defence, and later vehicles had a remote-controlled machine gun mount. The StuG IV’s crew layout was standard for a German assault gun, and its crews were trained in the same way as StuG III crews.

4. Technical Specifications

Dimensions and Weight

The StuG IV measured about 5.92 metres long, 2.88 metres wide and 2.2 metres high, with a ground clearance of about 0.4 metres. Combat weight was about 23 tonnes, which was lighter than the Jagdpanzer IV’s 24 to 25.8 tonnes, and the vehicle’s weight was a result of its casemate and gun. The StuG IV could cross a trench about 2.3 metres wide, climb a vertical obstacle of about 0.6 metres, and ford water up to about 1 metre deep. Its dimensions were similar to the Panzer IV’s, though its height was lower because it had no turret.

Engine and Performance

The Maybach HL 120 TRM was a 12-cylinder, water-cooled petrol engine producing 300 hp at 3,000 rpm, driving through a five-speed gearbox. The power-to-weight ratio of about 13 hp per tonne gave the StuG IV adequate performance, and fuel capacity was about 470 litres, giving a road range of about 210 km and a cross-country range of about 130 km. The engine was the same as the Panzer IV’s, and maintenance units were familiar with it, but by 1944 fuel shortages often limited operations more than mechanical problems did. The StuG IV’s engine was reliable, and the vehicle’s mechanical reliability was good, especially compared with the heavier German tanks.

Protection in Detail

Frontal armour was 80 mm on the casemate front and 80 mm on the hull front, both well sloped. Side armour was 30 mm on the casemate and 30 mm on the hull, with 5 mm Schürzen plates on many vehicles. Rear armour was 20 mm, and roof armour was 10 to 20 mm. The StuG IV’s frontal armour was thick enough to stop the Soviet 76.2 mm gun and the British 6-pounder at normal ranges, and it gave the vehicle good protection in its assault and tank destroyer roles. The side and rear armour were thinner, and the vehicle was vulnerable to flanking fire, but in its intended role — fighting from the front — its frontal protection was its main asset.

5. Armament

The 7.5 cm StuK 40 L/48

The StuG IV’s main armament was the 7.5 cm StuK 40 L/48, a version of the standard German 7.5 cm anti-tank gun adapted for mounting in a casemate. The gun fired a 6.8 kg armour-piercing round at a muzzle velocity of about 750 m/s, and it could penetrate about 106 mm of armour at 500 metres and about 85 mm at 1,000 metres. That was enough to destroy a Sherman or a T-34 at normal combat ranges, though it struggled against the frontal armour of the Soviet IS-2 and the British Churchill at long range. The L/48 was accurate and reliable, and it was the standard gun of the StuG III and the Panzer IV, which simplified ammunition supply.

Firepower in Combat

In combat, the StuG IV’s 7.5 cm gun proved effective against the Allied tanks it faced: the Sherman, the T-34, the Churchill and the Cromwell. The gun’s accuracy and its high rate of fire made it a dangerous weapon in the hands of a trained crew, and the StuG IV’s low silhouette made it hard to spot and hit. The vehicle’s gun was, however, less powerful than the Jagdpanzer IV’s L/70 gun, and it could not reliably penetrate the frontal armour of the heaviest Allied tanks at long range. The StuG IV’s firepower was adequate for 1944–1945, when it faced mainly Shermans and T-34s, but it was not as good as the best German tank destroyers.

Secondary Armament

The StuG IV carried a single MG 42 machine gun, mounted on the roof for defence against infantry and aircraft, and the crew carried personal weapons including MP 40 submachine guns. Late-production vehicles were fitted with a remote-controlled machine gun mount, which allowed the commander to fire the machine gun from inside the vehicle. The vehicle also carried a close-defence weapon in the roof, a small mortar that could fire smoke and explosive grenades at close range. These secondary weapons were important because the main gun’s limited traverse made the vehicle vulnerable to infantry at close quarters, and the StuG IV relied on its machine gun and on accompanying infantry for protection.

6. Variants

The Standard StuG IV

The standard StuG IV was the only version produced in significant numbers, with about 1,100 examples built between December 1943 and April 1945. The vehicle had a Panzer IV chassis, a StuG III casemate and a 7.5 cm StuK 40 gun, and a crew of four. The standard StuG IV served on all fronts, and it was the version most commonly encountered by the Allies in 1944–1945. The vehicle’s design did not change significantly during its production life, though there were minor improvements to the casemate and to the machine gun mounting.

The StuG IV Command Version

A small number of StuG IVs were built as command vehicles, with additional radio equipment and a reduced ammunition load. These vehicles were used by the commanders of the StuG brigades, and they were distinguished by their extra antennae. The command version was built in very small numbers, and it was not a separate production series, but a modification of the standard vehicle. The StuG IV’s command version was similar to the StuG III’s command version, and it served the same purpose.

Other Proposals and the StuH 42

A variant of the StuG IV mounting the 10.5 cm StuH 42 howitzer, designated the StuH 42, was proposed, but it was not built in significant numbers on the Panzer IV chassis — the StuH 42 was built on the StuG III chassis instead. Other proposals included a version with a different gun and a version with thicker armour, but none entered production. The StuG IV’s short production run and its role as a stopgap meant that it did not spawn a large family of variants, unlike the StuG III, which had many versions.

7. Combat Record

The Eastern Front, 1944–1945

The StuG IV first saw combat on the Eastern Front in early 1944, where it equipped the StuG brigades and the tank destroyer battalions of the German Army. The vehicle’s 7.5 cm gun was effective against the T-34 and the Sherman, and its low silhouette made it well suited to the defensive battles of 1944, when the German Army was retreating across Poland and into Germany. The StuG IV served in the battles for Warsaw, in East Prussia and in the defence of Berlin, where it was one of the last German armoured vehicles in service. Its service on the Eastern Front was intense, and its losses were heavy, but it remained in production until the end of the war.

Italy

In Italy the StuG IV served with the German forces in the defensive battles along the Gustav Line and the Gothic Line, where its low profile and powerful gun made it effective in the mountainous terrain. The vehicle’s service in Italy was limited by the terrain and by the Allied air superiority, and many vehicles were lost to air attack and to mechanical failure. The StuG IV’s service in Italy was, however, valuable, and it was used to cover withdrawals and to hold key road junctions, roles in which its gun and its armour were well suited.

The Western Front and the Ardennes

On the Western Front the StuG IV served in Normandy, in the Ardennes and in the defence of Germany in 1944–1945. In the Ardennes offensive of December 1944, StuG IVs were used to support the infantry in the attack on American positions, and their 7.5 cm guns were effective against the Sherman tanks and the American infantry. By the end of the war, most StuG IVs had been lost, and the survivors were few. The vehicle’s combat record was, in the end, a story of a good weapon built in the last year of the war, when Germany needed every vehicle it could produce, and one that served well despite the desperate circumstances.

8. Operators

Germany

Germany was the StuG IV’s main operator, using the vehicle in the StuG brigades and in the tank destroyer battalions of the panzer and panzergrenadier divisions. The vehicle equipped the independent StuG brigades, which were attached to armies and army groups as needed, and it served on all fronts. The StuG IV was one of the more numerous German armoured fighting vehicles of 1944–1945, and it remained in service until the end of the war. StuG IVs were organised in the same Sturmgeschütz brigades as the StuG III, and the two types often served side by side, sharing ammunition, spares and maintenance, which simplified supply in the last year of the war.

Finland, Romania and Others

Finland received a small number of StuG IVs from Germany, and used them in the Continuation War and in the Lapland War, though the vehicle’s service in Finland was limited. Romania also received StuG IVs, and used them on the Eastern Front, though in small numbers. The StuG IV’s service with these armies was limited, but it showed the wide distribution of German armoured vehicles under the Axis system, and the vehicle’s reliability and its gun made it attractive to Germany’s allies.

Captured Vehicles

The Western Allies and the Soviet Union captured StuG IVs in some numbers, and several were tested at proving grounds in Britain, the United States and the Soviet Union. The Allies were impressed by the vehicle’s low silhouette and its gun, but they did not put it into service, because they had their own assault guns and because the StuG IV’s production was too small to be significant. Captured StuG IVs were used for trials and for display, and several survive in museums today.

9. Legacy

A Stopgap That Worked

The StuG IV’s main legacy is as a stopgap that worked: a vehicle designed in a month to replace the StuG III, which became a standard weapon in its own right and served effectively for the last year of the war. The StuG IV showed that the German armoured vehicle industry could adapt quickly to disruption, and that a vehicle built from existing components could be effective. The StuG IV’s production in over 1,100 examples was a significant achievement, given the circumstances of 1944–1945, when German industry was under constant bombing and material shortages were severe.

Survivors and Memory

Several StuG IVs survive in museums, including the German Tank Museum at Munster, the Musée des Blindés at Saumur, the Kubinka Tank Museum in Russia and the United States Army Ordnance Museum. The vehicle is a popular subject for modellers, and its similarity to the StuG III makes it easy to confuse with its more famous predecessor, though its Panzer IV chassis and its different superstructure distinguish it. The StuG IV is remembered as the StuG III’s late-war replacement, and as a good assault gun that served in the desperate final year of the war.

Assessment

Historians generally judge the StuG IV as a good assault gun, though not as good as the StuG III in terms of overall numbers and service. Its gun was effective, its armour was adequate and its chassis was reliable, but it was built in smaller numbers and it arrived too late to make a decisive difference. The StuG IV’s importance lies in its demonstration of German industrial adaptability, and in its service as a valuable weapon in the last year of the war, when every armoured vehicle counted. The vehicle remains, however, a footnote to the StuG III’s story, and its reputation is overshadowed by its more numerous predecessor.

10. FAQ

How many StuG IVs were built?

About 1,100 to 1,150 StuG IVs were built between December 1943 and April 1945, by the Krupp-Grusonwerk in Magdeburg. The total includes the standard version and a small number of command vehicles, and production ended in April 1945, when the war came to a close. The StuG IV was the last German assault gun to enter production, and it was built in smaller numbers than the StuG III, which was produced in about 10,000 examples. It was introduced in late 1943 as a replacement for the StuG III, whose production was disrupted by Allied bombing, and it served until the end of the war in May 1945.

What was the difference between the StuG IV and the StuG III?

The StuG IV was built on a Panzer IV chassis, while the StuG III was built on a Panzer III chassis. The StuG IV was slightly larger and heavier, and it had a different superstructure, but it mounted the same 7.5 cm StuK 40 gun and had a similar crew and armour. The StuG IV was developed as a replacement for the StuG III after the Alkett factory was bombed in November 1943, and the first StuG IV was completed in December 1943. The two vehicles had a similar crew of four and armour up to 80 mm at the front.

Could the StuG IV destroy a Sherman tank?

Yes, the StuG IV’s 7.5 cm StuK 40 gun could penetrate a Sherman’s frontal armour at normal combat ranges, and it could destroy a Sherman at up to 1,000 metres. The StuG IV was a dangerous opponent for any Allied tank, and its low silhouette made it hard to spot and hit. In Normandy and on the Eastern Front, StuG IVs accounted for a significant number of Allied tank losses, and the vehicle served on both fronts and in Italy. The StuG IV was an effective weapon in the last year of the war, when Germany needed every armoured fighting vehicle it could produce.

Why was the StuG IV built?

The StuG IV was built because the Alkett factory, which built the StuG III, was damaged by Allied bombing in November 1943, and StuG III production fell. The German Army needed a replacement that could be built quickly using existing chassis, and the Krupp company proposed mounting the StuG III’s casemate on a Panzer IV chassis. The first StuG IV was completed in December 1943, only a month later, and about 1,100 to 1,150 StuG IVs were built between December 1943 and April 1945. The vehicle used the Panzer IV’s chassis, engine and running gear, and it remained in service until the end of the war in May 1945.

What engine did the StuG IV use?

The StuG IV used the Maybach HL 120 TRM, a 12-cylinder petrol engine producing 300 hp, the same engine as the Panzer IV. Top speed was about 40 km/h on roads, and the range was about 210 km, for a vehicle that weighed about 23 tonnes. The engine was reliable and well understood by German maintenance units, and spare parts were shared with the Panzer IV. The vehicle carried a crew of four, a commander, gunner, loader and driver, and it was armed with the 7.5 cm StuK 40 L/48 gun.

Where can I see a StuG IV today?

Surviving StuG IVs are displayed at the German Tank Museum in Munster, the Musée des Blindés at Saumur in France, and the Kubinka Tank Museum in Russia. They are also displayed at the United States Army Ordnance Museum, among others, and the vehicle is often confused with the StuG III. Its Panzer IV chassis and its different superstructure distinguish it from the StuG III, and about 1,100 to 1,150 StuG IVs were built. The StuG IV was built on the Panzer IV chassis and armed with the 7.5 cm StuK 40 gun, and it served on the Eastern Front, in Italy and on the Western Front.

11. Sources

• Chamberlain, Peter and Doyle, Hilary. Encyclopedia of German Tanks of World War Two. Arms and Armour Press, 1999.
• Jentz, Thomas. Panzertruppen, Volume 2: The Complete Guide to the Creation and Combat Employment of Germany’s Tank Force, 1943–1945. Schiffer, 1996.
• Spielberger, Walter. Panzer IV and Its Variants. Schiffer, 1993.
• Zaloga, Steven. StuG III and StuG IV. Osprey New Vanguard series.