German Medium Tank Panzerkampfwagen III from Ausf. H to Ausf. N

In the mid-1930s German authorities intensified their efforts to find a way around the post-war limitations imposed on the country by the Treaty of Versailles.

Hitler’s drive to modernize his armed forces gained a new momentum with the arrival on stage of Col. Heinz Guderian – the future spiritus movens of German armored warfare doctrine. Behind the scenes German design teams were busy working on prototypes of vehicles that would soon become the tools of the future war – light Pz.Kpfw. I and II, heavy (in keeping with contemporary classification) Pz.Kpfw. IV and medium Pz.Kpfw. III armed with a 37 mm gun. In the early stages of fighting in France it became clear that the vehicle didn’t carry enough punch and in later marks of the tank the 37 mm main gun was superseded by a 50 mm weapon. The ultimate version of the Pz.Kpfw. III was armed with a short barrel 75 mm gun, the largest that the tank’s turret could accommodate.

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Zugführerwagen

It was already in the mid-1920s that first efforts were made to equip German army with tanks. Early attempts to design and build a thoroughly modern armored vehicle can be traced to December 1933 when Krupp received a requirement from Heereswaffenamt (Army Ordnance Office) for a 10 ton tank armed with a 37 mm main gun and machine guns.
During a meeting held on January 11, 1934, where the future needs of armed forces were discussed, a decision was made to procure armored combat vehicles. As a result, two types of tanks were to be developed: the basic tank, initially designated Gefechtskraftwagen 3.7 cm (Vskfz. 619) armed with a 37 mm gun mounted in a rotating turret and an escort tank (Begleitwagen - B.W., manufactured as the Pz.Kpfw. IV) armed with a heavier caliber weapon. The former were later “camouflaged” as a Zugführerwagen – Z.W., or a platoon’s leader tank. In official documentation that vehicle can be found under several different designations:
– 3.7 cm Geschütz–Kampfwagen,
– 3.7 cm Geschütz–Panzerwagen (Vskfz. 619),
– 3.7 cm Geschütz–Panzerkampfwagen,
– 3.7 cm Panzerkampfwagen.
Before long, Waffenamt Prüfwesen 6 (department of the Army Ordnance Office responsible for development of armored and mechanized equipment) formulated key technical specifications of the future Z.W. tank. Weighing in at 10 tons, the vehicle was to be manned by a crew of five. A six-speed Zahnradfabrik Friedrichshafen SSG 75 transmission was to be coupled to a liquid-cooled Maybach HL 100 engine developing 300 hp to accelerate the tank to a speed of 40 km/h.

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Work on the Z.W. medium tank began simultaneously at Friedrich Krupp plant in Essen, Rheinische Metallwaren und Maschinenfabrik AG in Berlin (after merger with August Borsig GmbH the company operated as Rheinmetall-Borsig AG), Maschinenfabrik-Augsburg-Nürnberg AG (MAN) in Augsburg-Nuremberg and Daimler-Benz AG in Berlin. The last three were involved in the design of the chassis, with the task to build a prototype eventually going to MAN and Daimler-Benz. Rheinmetall (whose chassis didn’t make the grade) and Krupp (didn’t participate in the chassis design) were in turn given contracts to develop the new tank’s turret. In addition, Daimler-Benz was directed to develop a chassis with an alternative configuration of the running gear, designated as Z.W. 3 and Z.W. 4.
By August 1934 Krupp had delivered two test turrets (Turm 1 and Turm 2). Following live fire tests carried out on August 20, 1935 in Meppen, some modifications were recommended before the turrets could be cleared for a full-scale production. The following August Daimler-Benz delivered their chassis prototype designated Z.W. 1, while MAN most likely didn’t complete the assigned task. In late 1935 turrets designed and built at Rheinmetall and Krupp were mated to the Z.W. 1 chassis, before the vehicles were sent for tests. During field tests the prototype equipped with Krupp’s turret performed better and was subsequently selected for a full-scale production.

 

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Versions armed with a 37 mm gun
Daimler-Benz received an order for ten Pz.Kpfw. III vehicles in December 1935 and by the end of 1937 all ten examples had rolled off the assembly lines. The vehicles received chassis numbers 60101 to 60110, official designation Pz.Kpfw. III (3.7 cm) Ausführung A (factory designation 1 Serie/Z.W.) and ordnance inventory number 141 (Sonderkraftfahrzeug 141, or Sd.Kfz. 141).
The tank’s running gear consisted of a pair of drive wheels, two idler wheels, two pairs of return rollers and five pairs of cast steel, rubber-rimmed double road wheels supported by steel arms and coil spring suspension.