Sturmgeschütz III

The Sturmgeschütz III (or StuG III) is the only tracked weapon to serve with the German forces throughout World War II in its same basic form. 

Internally, the StuG III consists of two compartments; the rear for the 300hp Maybach power plant and the forward or crew compartment/superstructure.

The driver was located at the left front of the vehicle.  The gunner sat behind the driver and the commander directly behind the gunner.  On the right side of the vehicle was the loader/operator.  Next to him were the ammunition racks.  The radio (a 10W UKW at this time) was in the pannier on the left side.  A second radio was usually fitted in the right pannier on command vehicles.

The design of the StuG has some advantages over a traditional turreted tank.  The lack of a turret meant reduced height (6’4”) and reduced weight.  This allowed better armor protection; 50mm in front/superstructure with the superstructure sides further protected by angled 9mm plates of spaced armor.
The design had some flaws as well.  Being mounted in the hull, the traverse on the gun was very limited (typically 20-24°). On early models the gunner’s sight looked through a slot in the armor plating; the commander could only observe things through periscope binoculars via his open hatch (exposing him to fire) and there was no machine gun for close defense.  

Ausfuhrüngen (models or versions)

StuG III Ausf.A (Sd.Kfz 142; 1940, 30 produced) - The StuG III Ausf.A used the chassis of the Panzer III Ausf.F and mounted the low-velocity 7.5cm StuK37 L/24 gun

StuG III Ausf.B (Sd.Kfz 142; 1940-41, 320 produced) – Improved transmission and wider tracks fitted (40cm).  The wider tracks necessitated a change in drive sprockets and idler wheels (some retained the older drive sprockets and idlers by inserting spacer rings to widen them.  Mounted the same low-velocity 7.5cm StuK37 L/24 gun.

StuG III Ausf.C (Sd.Kfz 142; 1941, 50 produced) – Superstructure modified to remove the gunner’s sighting slot in the roof (this had proved to be a weakness in the armor of the Ausf. A & B).  The gunner’s sight protrudes through the roof armor.  Mounted the 75.cm StuK37 L/24 gun.

StuG III Ausf.D (Sd.Kfz 142; 1941, 150 produced) – Externally identical to the Ausf. C, the differences being in internal arrangement.

StuG III Ausf.E (Sd.Kfz 142; 1941-42, 272 produced) – 9mm external armor plates discarded.  30mm superstructure side plates now vertical.  Left side radio pannier expanded and right side radio pannier fitted as standard (this was used for ammunition stowage when no second radio was fitted).  Mounted the 75.cm StuK37 L/24 gun.

StuG III Ausf.F (Sd.Kfz 142/1; 1942, 359 produced) - The first major change in the series. The 7.5 cm StuK37 L/24 is replaced with the 7.5 cm StuK40 L/43. Additional 30mm plates bolted to the front armor.  Additional protection was sometimes achieved by pouring concrete into the hollow spaces at the front of the superstructure roof.  A ventilator was added on the roof and a close defense machine gun and folding shield were added in front of the loader’s hatch.  These modifications mark the official transition of the StuG changing from being an infantry support vehicle to a tank/anti-tank vehicle.
 
StuG III Ausf.F/8 (Sd.Kfz 142/1; 1942, 334 produced) - Replaced the 7.5 cm StuK 40 L/43 with the 7.5 cm StuK40 L/48.  Existing Ausf.F StuGs were eventually retrofitted with the StuK40 L/48.  Otherwise identical to the Ausf. F.
StuG III Ausf.G (Sd.Kfz 142/1; 1942-45, 7,893 produced) - The ubiquitous StuG model. Commander's cupola (eight separate episcopes, split hatch to allow use of periscope binoculars with just the smaller front half open); 80mm frontal armor; superstructure widened over the tracks; ventilator moved from the roof to the rear wall of the superstructure; loader’s hatch changed to open fore and aft.  

Some of the early Ausf.Gs (frühe) retained the block mantlet of the Ausf.F/8’s.  However, a majority of them were fitted with the Topfblende (pot mantlet).  In mid-1943 Schürzen skirt armor was available to protect against anti-tank rounds. 

In late spring of 1944 the late model (spät) of the Ausf.G appeared; Schürzen skirt armor; anti-magnetic Zimmerit paste (to prevent the attachment of magnetic mines).  Some Ausf.Gs carried a Nahverteidigungswaffe (close-in defense weapon - basically a pop-up grenade) and a remote controlled MG was added to the roof.  Some vehicles carried three smoke bomb dischargers on either side of the front superstructure.