Make your own free website on

banner.JPG (13650 bytes)


StuG III ausf. A (Sd.kfz 142)

After the first 5 prototypes of the "O" series had been constructed and tested, changes were made in the design of the vehicle, and a new chassis was selected.  The "O" vehicles had been built on the chassis of the PzKpfw III ausf B, in itself a developmental design, and the production vehicles "Gepanzerte Selbstfahrlafette für Sturmgeschütz 7,5cm Kanone ausf A, Sd.kfz 142 (later called StuG III ausf A) were based on the chassis of the PzKpfw III ausf F .
The hulls were not tank components, being modified to suit the Stug III layout and having heavier armor, but the power train and suspension components were the same as those of the PzKpfw III ausf F (5/ZW).
The superstructure, bolted to the chassis with angles, was a low, relatively spacious fixed compartment with a multi-angled roof design and heavy frontal armor of 50mm thickness.  The chassis nose plates were also 50mm thick as was the gun mantlet; there was another 50mm plate behind the driver, at the foward end of the fighting compartment, and from the front, the StuG III ausf A was very well protected against the anti-tank guns of the period.  The vertical side plates were 30mm thick, the glacis plate was a 26mm, and the roof plates were 11mm.  On the left side was a rectangular armored pannier for the radio installation.  In front of this box on the left, and all along the right side wall, an angled series of plates of 9mm thick formed an outer wall which extended over the part of the mudguards.  These angled plates were intended as a extra spaced armor; nothing was stowed behind them, and there was no access to the space enclosed.  The rear superstructure and rear hull plates were 30mm thick, and the belly was 16mm thick, with 20mm lower nose and tail plates.
The gun was the standard 7,5cm L/24 KwK 37 then being fitted to the PzKpfw IV medium tank, which was intended as a support vehicle for armored formations.  Thus, since the StuG  had not be intended to fight tanks or other moving targets, it did not need a turret, and slightly smaller PzKpfw III chassis could mount the same gun.  The mounting developed by Krupp was relatively primitive, consisting of a pedestal which was bolted to the floor, and with the simple elevation and traverse mechanisms.  No bullet splash protection was provided; this was particulary serious at maximum elevation.  A canvas dust cover was provided to close the space around the mounting and protect the crew and equipment from dust and rain.
Access to the fighting compartment was through 3 hatches in the roof; in an emergency, the driver could escape through the inspection hatches in the glacis plate.  The driver sat in front on the left; behind him was the gunner, and the commander occupied the left rear corner of the superstructure.  The loader was at the right rear of the fighting compartment.  The gunner's sight was internal, requiring a small aperture in the front plate, and a V-shaped cutout was made in the roof armor over the driver's compartment to allow a wider field of vision for the gunner.  Metal ribs wer welded in place to deflect ricocheting bullets and fragments.
The mechanical details were the same as the PzKpfw III ausf F.  The suspension consisted of 6 pairs of roadwheels on each side, each set sprung by the torsion bars and arms, with the shock absorbers on the first and last axles.  Because the torsion bars were paired, the wheels on the left were slightly behind those on the right side.  Three return rollers were fitted, spaced equally.  A built up, solid rear idler was used, and the cast drive sprocket had 8 lightening holes in the centers, driving 36cm cast skeleton type tracks.  The engine was a 12 cylinder Maybach HL120TR rated at 300hp, and the transmission was the 10-speed preselective Variorex type.  Steering was by clutch and brake.
Production began early in 1940, and 4 batteries of StuG III ausf A's saw service during the invasion of France in May, 1940.  Additional units worked up to service status after the end of the campaign.

StuG III ausf A


A StuG III seen in Holland, 1940.  Here can be seen the early chassis layout, based on the chassis of the PzKpfwf III ausf F; note the early drive sprocket, rear idler, and roller spacing.

Go back

Copyright Simon Vosters 1999-2000 ®