150mm sIG-33
15-cm schweres Infanteriegeschütz 33
Overview
150mm sIG-33
Frontal view of a German 15-cm schweres Infanteriegeschütz 33 on display at the Belgrade military museum.
Source: Unknown author -
© Copyright lies with original owner
Nazi Germany - BMM
German for "heavy infantry gun 33"
Description
Introduction
The sIG-33 is a World War 2 era heavy infantry gun of German origin. It was developed in the interbellum based on experience gained during World War 1. What makes the sIG-33 unique is that it was the only large caliber infantry gun in widespread service during the war. Despite obvious drawbacks it was deemed effective and was produced until the very end of the war. This iconic piece of equipment saw action in all German theaters of war. The concept of the heavy infantry gun saw no use after the war.
Design
The sIG-33 looks more like an artillery piece than an infantry gun. Infantry guns are often smaller and have more in common with the smaller anti-tank guns. The sIG-33 uses a rigid box chassis. This allows the gun to be used instantly, but reduces the maximum traverse. It has a large recuperator to reduce the significant recoil. A gun shield is fitted. Separate loading ammunition is used, with a six charge system.
Firepower
The sIG-33 fires at a rather low muzzle velocity of 240 m/s. A high angle of fire is deemed favorable in an infantry gun. Still it has a maximum range of 4.7 km. Practical rate of fire was 2 to 3 rpm. Some sources indicate 3 to 4 rpm. Main ammunition types were high explosive fragmentation and smoke. During the war a shaped charge warhead was introduced for use against armored vehicles and concrete. Later the muzzle loaded Stielgranate 42 demolition charge was introduced. This had over 54 kg of amatol explosive filler, compared to the 7.8 kg for the HE-fragmentation shell.
Mobility
Mobility is the main drawback of the sIG-33. Crews can move the sIG-33 by hand over short distances. During the entire war the sIG-33 was used both with a limber and six horses, as well as being towed by trucks. Various self-propelled mounts were produced. These greatly increased the mobility at the cost of a larger silhouette. Several hundred guns were produced using lighter alloys. These were mainly used with paratrooper formations. Lack of such materials saw a return to the original design. For use on the Eastern front the sIG-33 could be issued with several designs of sleds.
Protection
A gun shield provides a limited degree of protection over the frontal arc. The long range for an infantry gun provides some standoff range. Especially against smaller caliber high velocity anti-tank guns. However, the sIG-33 is often employed within range of medium and heavy mortars, as well as tube artillery such as the ubiquitous Soviet ZiS-3. The lack of movement makes it vulnerable to counter battery fire by these high angle weapon systems.
Users
The sIG-33 was produced in large numbers. It was used from the early stages of World War 2 all the way up till the end. Many self-propelled mounts were used as well. At the start of World War 2 Germany had 410 guns. Production increased steadily with peak production reached in February of 1945. From 1943 onward the sIG-33 began to be supplemented by 8-cm and 12-cm mortars. During World War 2 a German 12-cm mortar was over 15 times cheaper to produce than a sIG-33.
Details
Media
150mm sIG-33
German 15-cm schweres Infanteriegeschütz 33 used by the Großdeutschland division in 1942.
Source: Bundesarchiv, Bild 146-2006-0057
Copyright: CC BY-SA 3.0
150mm sIG-33
German 15-cm schweres Infanteriegeschütz 33 on display at the Belgrade military museum as seen in 2006.
Source: Dungodung
Copyright: CC BY-SA 3.0
150mm sIG-33
Rear view of a German 15-cm schweres Infanteriegeschütz 33 on display at the Belgrade military museum.
Source: Unknown author
Copyright: Copyright lies with original owner
150mm sIG-33
Two German 15-cm schweres Infanteriegeschütz 33 with spoked wheels captured by British forces in Europe in December of 1944.
Source: War Office Second World War Official Collection
Copyright: Public domain
List of sIG-33 self-propelled guns
Note: incomplete list
Sturmpanzer I
In February of 1940 a total of 38 Panzer I ausf. B chassis were converted with an open superstructure to mount an entire sIG-33 infantry gun. These were used at least until 1943 on the Eastern front.
Sturmpanzer II Bison
Widened and lengthened Panzer II chassis with sIG-33 infantry gun. A total of 12 produced.
15cm sIG 33 auf Fahrgestell Pz.Kpfw. III (Sf.)
A single Panzer III chassis was converted with a 150mm sIG-33 and served in North Africa. This may have been a local modification of a damaged Panzer III.
Sturm-Infanteriegeschütz 33B
German makeshift assault gun with sIG-33 in a heavy casemate on a Panzerkampfwagen III chassis. A total of 24 vehicles produced.
Grille ausf. H
A sIG-33 on a Geschützwagen 38(t) chassis. The early model had a central fighting compartment and rear mounted engine. A total of 210 vehicles produced.
Grille ausf. K
A sIG-33 on an improved Geschützwagen 38(t) chassis with centrally located engine and rear fighting compartment. A total of 162 vehicles produced.
Related articles
12 cm Granatwerfer 42
During World War 2 the sIG-33 was partially replaced by the 12-cm Granatwerfer 42 on a 2 mortars for 1 sIG-33 basis.