According to the Treaty of Versailles, Germany was not allowed to build tanks or assemble an armoured force. However, Germans were in no hurry to meet the terms of a treaty they considered degrading. Even before the rise of the nazis, the German military began actively developing a tank doctrine. It was more difficult to implement this doctrine in practice, but the Germans managed it. During training exercises, tanks were represented by models built on top of cars, or even bicycles. The tanks themselves were developed under the label of agricultural tractors and tested abroad.
After the nazis seized power, Germany fully refused to be limited by the Treaty of Versailles. By that point, armoured doctrine was fairly developed, and all that remained was to build the Panzerwaffe in metal.
Germany's first tanks, the PzKpfw I and PzKpfw II, were vehicles that even the Germans viewed as a transitional step to real tanks. The PzI was designated as a training vehicle, but even it saw battle in Spain, Poland, France, North Africa, and the USSR.
In 1936, the first PzKpfw IIIs entered the armed forces, armed with a 37 mm anti-tank gun and protected by 15 mm of armour from the front. This vehicle was a real tank, fully compliant with the requirements of the day. However, its small gun could not defeat fortifications and engineering structures of the enemy.
In 1934, the army issued a request for a fire support tank, equipped with a 75 mm cannon that could fire high exposive rounds. At first, the vehicle was developed as a battalion commander's tank, which led to its name: BW (Batallionführerwagen). Three competing companies worked on the tank: Rheinmetall-Borsig, MAN, and Krupp AG. Krupp's VK 20.01 was deemed the best, but never made it to mass production, due to the tank's spring suspension. The military demanded torsion bars, which would provide smoother movement and better off-road performance. Krupp's engineers reached a compromise, and were allowed to use a spring suspension with eight paired road wheels, borrowed almost entirely from the experimental multi-turreted NbFz tank.
An order for the new tank, named Vs.Kfz. 618, was issued to Krupp in 1935. In April of 1936, it was renamed PzKpfw IV. The "zeroth" batch was produced at Hessen. In the fall of 1937, manufacturing was moved to Magdeburg, where the Ausf. A variant began production.
The PzKpfw IV was a vehicle with a classical layout, with an engine compartment in the rear. The transmission was located in the front, between the driver and radio operator. The turret was slightly to the left of the center axis due to the design of the turning mechanism. The suspension was composed of four bogeys per side, with four road wheels per bogey. The leading wheel was in the front. Throughout the service life of the PzKpfw IV, its suspension was never radically altered.
The Ausf. A modification was equipped with a Maybach HL108TR 250 hp engine, located closer to the right side of the hull. Ausf. A had 20 mm of armour in the front and 15 on the sides and rear. The turret had 30 mm of armour up front, 20 mm in the sides, and 10 in the rear. The cylindrical commander's cupola was located in the middle of the rear of the turret. It had six vision slits, protected by armoured glass.
PzKpfw IV Ausf A. was armed with a short barreled 75 mm gun KwK 37L/24, and two 7.92 mm MG34 machineguns, one coaxial, and one in the front of the hull. The front armoured plate had an angled shape. The machinegun and commander's cupola are two signs of the Ausf. A modification. 35 of these vehicles were built before June of 1938.
The PzKpfw IV was destined to become the main vehicle of Germany's armoured forces. Its latest modification was produced between June of 1944 and March of 1945. The size of this article does not allow for examination of each modification, so we must limit ourselves to brief overviews of major changes.
In May of 1938, PzKpfw IV Ausf. B started production. The main changes from the previous version were the straightening of the front of the turret platform and removing the hull machinegun. It was replaced by a vision port for the radio operator, and a port for his pistol. The commander's cupola received armoured covers for the vision slits. Instead of a 5 speed gearbox, the tank received a 6 speed one. The engine was swapped for a 300 hp Maybach HL120TR. The armour was improved. Now, the front of the hull and turret had 30 mm of armour. 42 vehicles were built before October of 1938.
PzKpfw IV Ausf. C received a new Maybach HL120TRM engine, with the same 300 hp. This engine remained on all subsequent modifications. Ausf. C remained in production between April 1938 and August 1939. It was followed by Ausf. D, in which the front of the turret platform was once again bent, and the machinegun returned. From 1940, the front of the tank was reinforced with an additional 30 mm armour plate. In 1941, some vehicles from this series were equipped with 50 mm guns. PzKpfw IV Ausf. D also had a tropical variant.
Ausf. E was manufactured from April 1940 to April 1941. The 30 mm of armour on the hull was reinforced with another 30. The hull machine gun received a ball mount. The turret's shape was slightly altered.
Ausf. F was the last PzIV with a short 75 mm gun. The front armour was 50 mm on the hull and 30 on the turret. Starting in 1942, Ausf. F vehicles received the long barreled KwK 40 75L/43 gun. This variant was named PzKpfw IV Ausf. F2.
Ausf. G began production in March of 1942. It was not radically different from the previous version of the tank. The front armour of the tank was 80 mm thick. Late vehicles of this type were equipped with wide "Eastern" tracks, extra front armour and skirt armour. About 400 Ausf. Gs were armed with L/43 guns. Starting from February 1943, PzKpfw IV Ausf. G tanks were equipped with KwK 40 75L/48 guns. PzKpfw IV Ausf. G was the basis for the Hummel SPG.
In June of 1942, work on the Ausf H. began. Front armour of the tank was 80 mm thick. It also had skirt armour, 5 mm thick. The commander's cupola was equipped with a mount for an AA 7.92 mm machinegun. The tank was covered in Zimmerit. The main gun of the tank was the 75 mm KwK 40 L/48.
The last modification of the tank, Ausf. J, began in February of 1944. The tank lacked a turret rotation mechanism; the turret had to be hand cranked. The idlers and road wheels were simplified. The side observation slits were removed, as they were covered by skirt armour and were deemed worthless. Various vehicles of this series differed in internal equipment.
In conclusion, the PzKpfw IV earned its title of the most versatile German tank in WWII. Its engineers left enough modernization potential in it for the tank to remain a functional combat vehicle through the entire war. The tank remained in use by various armed forces until the 1960s.
Original article available here.