Sturmgeschütz III


The Sturmgeschütz III assault gun was Germany's most-produced fully tracked armoured fighting vehicle during World War II, and second-most produced German armored combat vehicle of any type after the Sd.Kfz. 251 half-track. It was built on the chassis of the proven Panzer III tank, replacing the turret with an armored, fixed superstructure mounting a more powerful gun. Initially intended as a mobile assault gun for direct-fire support for infantry, the StuG III was continually modified, and much like the later Jagdpanzer, was employed as a tank destroyer.

Development

The Sturmgeschütz originated from German experiences in World War I, when it was discovered that, during the offensives on the Western Front, the infantry lacked the means to effectively engage fortifications. The artillery of the time was heavy and not mobile enough to keep up with the advancing infantry to destroy bunkers, pillboxes, and other minor fortifications with direct fire. Although the problem was well known in the German army, it was General Erich von Manstein who is considered the father of the Sturmartillerie. The initial proposal was from von Manstein and submitted to General Ludwig Beck in 1935, suggesting that Sturmartillerie units should be used in a direct-fire support role for infantry divisions. On 15 June 1936, Daimler-Benz AG received an order to develop an armoured infantry support vehicle capable of mounting a calibre artillery piece. The gun mount's fixed, fully integrated casemate superstructure was to allow a limited traverse of a minimum of 25° and provide overhead protection for the crew. The height of the vehicle was not to exceed that of the average soldier.
Daimler-Benz AG used the chassis and running gear of its recent Panzer III medium tank as a basis for the new vehicle. Prototype manufacture was passed over to Alkett, which produced five prototypes in 1937 on Panzer III Ausf. B chassis. These prototypes featured a mild steel superstructure and a Krupp short-barrelled, howitzer-like in appearance, 7.5 cm StuK 37 L/24 cannon. Production vehicles with this gun were known as Gepanzerte Selbstfahrlafette für Sturmgeschütz 7.5 cm Kanone Ausführung A bis D .
While the StuG was considered self-propelled artillery, it was not clear which land combat arm of the German Army would handle the new weapon. The Panzerwaffe, the natural user of tracked fighting vehicles, had no resources to spare for the formation of StuG units and neither did the infantry. It was agreed that it would best be employed as part of the artillery arm. The StuGs were organized into battalions and followed their own doctrine. Infantry support using direct-fire was its intended role. Later, there was also a strong emphasis on its use as an anti-tank gun.
As the StuG was designed to fill an infantry close support combat role, early models were fitted with a howitzer-pattern, low-velocity 7.5 cm StuK 37 L/24 gun, much as the earliest versions of the fully turreted Panzer IV were. Low-velocity shells are lightly built of thin steel and carry a large charge of explosive, to destroy soft-skin targets and blast fortifications. Such shells do not penetrate armour well. After the Germans encountered the Soviet KV-1 and T-34 tanks, the StuG was first equipped with a high-velocity 7.5 cm StuK 40 L/43 main gun and in the autumn of 1942 with the slightly longer 7.5 cm StuK 40 L/48 gun. These high-velocity guns were the same as those mounted on the Panzer IV for anti-tank use but the heavy steel wall high-velocity shells carried much less explosive and had a lower blast effect for use against infantry or field fortifications. These versions were known as the 7.5 cm Sturmgeschütz 40 Ausf.F, Ausf. F/8 and Ausf. G .
Beginning with the StuG III Ausf. G from December 1942, a 7.92 mm MG34 machine gun could be mounted on a shield on top of the superstructure for added anti-infantry protection. Some of the F/8 models were retrofitted with a shield. An additional coaxial 7.92 mm MG34 was introduced in Mid 1944 for some production and all production by autumn 1944.
The vehicles of the Sturmgeschütz series were cheaper and faster to build than contemporary German tanks; at 82,500 RM, a StuG III Ausf G was cheaper than a Panzer III Ausf. M, which cost 103,163 RM. This was due to the omission of the turret, which greatly simplified manufacture and allowed the chassis to carry a larger gun. By the end of the war, ~11,300 StuG IIIs and StuH 42s had been built.

Operational history

The Sturmgeschütz III-series of vehicles proved very successful and served on all fronts, from Russia to North Africa and Western Europe to Italy, as assault guns and tank destroyers. Because of their low silhouette, StuG IIIs were easy to camouflage and be hidden and were difficult targets to destroy. As of 10 April 1945, there were 1,053 StuG IIIs and 277 StuH 42s in German service. The StuG assault guns were cost-effective compared to the heavier German tanks such as the Tiger I and the Panther, although as anti-tank guns they were best used defensively as the lack of a traversable turret and its generally-thin armour was a severe disadvantage in the attack role. As the situation for the German military deteriorated further later in the war, more StuGs were built than tanks, particularly due to ease of production.
In 1943 and 1944, the Finnish Army received 59 StuG III Ausf. Gs from Germany and used them against the Soviet Union. Thirty of the vehicles were received in 1943 and a further twenty-nine obtained in 1944. The first batch from 1943 destroyed at least eighty-seven enemy tanks for a loss of only eight StuGs. The later batch from 1944 saw no real action. After the war, the StuGs were the main combat vehicles of the Finnish Army up until the early 1960s when they were phased out. These StuGs gained the nickname "Sturmi" in the Finnish military, which can be found in some plastic scale-model kits.
100 StuG III Ausf. Gs were delivered to Romania in the autumn of 1943. They were officially known as TAs in their army's inventory. By February 1945, 13 were still in use with the 2nd Armoured Regiment. None of this initial batch survived the war. Thirty-one TAs were on the Romanian military's inventory in November 1947. Most of them were probably StuG III Ausf. Gs and a small number of Panzer IV/70 . These TAs were supplied by the Red Army or were damaged units repaired by the Romanian Army. All German equipment was removed from service in 1950 and finally scrapped four years later due to the army's decision to use only Soviet armour.
StuG IIIs were also exported to other nations friendly to Germany, including Bulgaria, Hungary, Italy, and Spain. Hungary fielded its StuG IIIs against Soviet forces as they invaded their country in end-1944 up until early 1945. As with Hungary, Bulgaria received several StuGs from Germany too but almost none saw service against the Soviets, the country having ended the alliance with Germany by switching sides to the Allies before the Soviets invaded. Post-WWII, these were used for a short time before being turned into fixed gun emplacements on the Krali Marko Line on the border with neighbouring Turkey. StuG IIIs were also given to the pro-German Ustashe Militia in Yugoslavia, most of which were captured in Yugoslavia by Tito's Yugoslav partisans during and after the war, as did German-operated vehicles. These were used by the Yugoslav People's Army until the 1950s when they were replaced by more modern combat vehicles. Spain received a small number of StuG IIIs from Germany during WWII, later sold to Syria between 1950 and 1960. Italy received the smallest number of StuG IIIs Germany distributed in the war, with only 3.
After the Second World War, abandoned German StuG IIIs remained behind in many European nations Germany occupied during the war years, such as in Czechoslovakia, France, Norway and Yugoslavia. The Soviet Union also captured hundreds of ex-German StuGs, most ending up being donated to Syria, which continued to use them along with other war surplus armoured fighting vehicles received from the USSR or Czechoslovakia during the 1950s and up until the War over Water against Israel in the mid-1960s. By the time of the Six-Day War in 1967, all of them had been either destroyed, stripped for spare parts, scrapped or emplaced on the Golan Heights as pillboxes. None remain in service today. A few Syrian StuG IIIs ended up in Israeli hands and have become war memorials or simply left rusting away on former battlefields.

Variants

Production numbers were:
A rotating cupola with periscopes was added for the Ausf G.'s commander. However, from September 1943, the lack of ball bearings forced cupolas to be welded on. Ball bearings were once again installed from August 1944. Shot deflectors for the cupolas were first installed from October 1943 from one factory, to be installed on all StuGs from February 1944. Some vehicles without shot deflectors carried several track pieces wired around the cupola for added protection.
From December 1942, a square machine gun shield for the loader was installed, allowing an MG34 to be factory installed on a StuG for the first time. When stowed this shield folded back, partially overlapping the front half of the loader's hatch cover. A curved protrusion welded to the backside of the shield pushed the shield forward as the front half of the loader's hatch cover was opened and guided the hatch cover to naturally engage a latch point on the shield thus, supporting the shield in its deployed position without exposing the loader to hostile forward fire. F/8 models had machine gun shields retro-fitted from early 1943. The loader's machine gun shield was later replaced by rotating machine gun mount that could be operated by the loader inside the vehicle sighting through a periscope. In April 1944, 27 of them were being field tested on the Eastern front. Favourable reports led to installation of these "remote" machine gun mounts from the summer of 1944.
From October 1943, G versions were fitted with the Topfblende pot mantlet gun mantlet without a coaxial mount. This cast mantlet, which had a sloped and rounded shape, was more effective at deflecting shots than the original boxy Kastenblende mantlet that had armour varying in thickness from 45 mm to 50 mm. The lack of large castings meant that the trapezoid-shape boxy mantlet was also produced until the very end. A coaxial machine gun was first added to boxy mantlets, from June 1944, and then to cast Topfblende, from October 1944, in the middle of "Topfblende" mantlet production. With the addition of this coaxial machine gun, all StuGs carried two MG 34 machine guns from fall of 1944. Some previously completed StuGs with a boxy mantlet had a coaxial machine gun hole drilled to retrofit a coaxial machine gun; however, Topfblende produced from November 1943 to October 1944 without a machine gun opening could not be tampered with.
Also from November 1943 onwards, all-metal return rollers of a few different types were used due to lack of rubber supply. Zimmerit anti-magnetic coating to protect vehicles from magnetic mines was applied starting in September or November 1943 and ending in September 1944.

Further variants

In 1942, a variant of the StuG Ausf. F was designed with a true howitzer instead of the 7.5 cm StuK 40 L/43 cannon. These new vehicles, designated StuH 42, were designed to provide infantry support with the increased number of StuG III Ausf. F/8 and Ausf. Gs being used in the anti-tank role. The StuH 42 mounted a variant of the 10.5 cm leFH 18 howitzer, modified to be electrically fired and fitted with a muzzle brake. Production models were built on StuG III Ausf. G chassis. The muzzle brake was often omitted due to the scarcity of resources later in the war. Alkett produced 1,299 StuH 42 from March 1943 to 1945, the initial 12 vehicles were built on repaired StuG III Ausf. F and F/8 from the autumn of 1942 to January 1943.
In 1943, 10 StuG IIIs were converted to the StuG III configuration by replacing the main gun with a Schwade flamethrower. These chassis were all refurbished at the depot level and were a variety of pre-Ausf. F models. There are no reports to indicate that any of these were used in combat and all were returned to Ausf. G standard at depot level by 1944.
In late 1941, the StuG chassis was selected to carry the 15 cm sIG 33 heavy infantry gun. These vehicles were known as Sturm-Infanteriegeschütz 33B. Twenty-four were rebuilt on older StuG III chassis of which twelve vehicles saw combat in the Battle of Stalingrad, where they were destroyed or captured. The remaining 12 vehicles were assigned to 23rd Panzer Division.
Due to the dwindling supply of rubber, rubber-saving road wheels were tested during 8–14 November 1942, but did not see production.
Bombing raids on the Alkett factory resulted in significant drops in StuG III production in November 1943. To make up for this loss of production, Krupp displayed a substitution StuG on a Panzer IV chassis to Hitler on 16–17 December 1943. From January 1944 onwards, the StuG IV, based on the Panzer IV chassis and with a slightly modified StuG III superstructure, entered production.
Field modifications were made to increase the vehicle's survivability, resulting in diversity to already numerous variants; cement plastered on front superstructure, older Ausf.C/D retrofitted with a KwK 40 L/48 gun, Ausf.G mounting Panzer IV cupola, a coaxial MG34 through a hole drilled on a boxy mantlet, et cetera.
The Soviet SU-76i self-propelled gun was based on captured StuG III and Panzer III vehicles. In total, Factory #37 in Sverdlovsk manufactured 181 SU-76i plus 20 commander SU-76i for Red Army service by adding an enclosed superstructure and the 76.2 mm S-1 tank gun.
Approximately 10,000 StuG IIIs of various types were produced from 1940 to 1945 by Alkett and from 1943 to 1945 by MIAG. From April to July 1944, some 173 Panzer III were converted into StuG III Ausf. G. The 1,299 StuH 42 and the 12 conversions from StuG III were solely built by Alkett.

Gallery

Operators

In working order
, Kent.
More or less intact, but not in working order