Panzer III
The Panzerkampfwagen III , commonly known as the Panzer III, was a medium tank developed in the 1930s by Germany, and was used extensively in World War II. The official German ordnance designation was Sd.Kfz. 141. It was intended to fight other armoured fighting vehicles and serve alongside and support the similar Panzer IV, which was originally designed for infantry support.
Initially, the Panzer III had the same 3.7 cm gun as the infantry used in an anti-tank role, but later models were given the 5 cm KwK 38 gun. This was the largest gun that could be fitted within the physical limitations of the turret ring, but it turned out to be ineffective against Soviet T-34 and KV-1 tanks. The Panzer IV, which had a larger turret ring, was redesigned to mount the long-barrelled 7.5 cm KwK 40 gun and became the main German tank instead. Produced from 1942 onwards, the last version of the Panzer III mounted the short barrelled 7.5 cm KwK 37 L/24 which was used on the first Panzer IVs, meaning the Panzer III and the Panzer IV had effectively swapped roles.
Production of the Panzer III ceased in 1943, but the StuG III assault gun, which was based on the Panzer III chassis, remained in production until the end of the war. About 18,000 vehicles based on the Panzer III chassis were produced between all variants --- by far the most of any German AFV design in World War II, and accounting for over a quarter of all tanks and assault guns produced by Nazi Germany.
Development history
Background
At the time, German tanks were expected to carry out one of two primary tasks when assisting infantry in breakthroughs, exploiting gaps in the enemy lines where opposition had been removed, moving through and attacking the enemy's unprotected lines of communication and the rear areas. The first task was direct combat against other tanks and other armoured vehicles, requiring the tank to fire armour piercing shells.On January 11, 1934, following specifications laid down by Heinz Guderian, the Army Weapons Department drew up plans for a medium tank with a maximum weight of and a top speed of. It was intended as the main tank of the German Panzer divisions, capable of engaging and destroying opposing tank forces, and was to be paired with the Panzer IV, which was to fulfill the second use: dealing with anti-tank guns and infantry strong points, such as machine-gun nests, firing high-explosive shells at such soft targets. Such supportive tanks designed to operate with friendly infantry against the enemy generally were heavier and carried more armour.
The direct infantry-support role was to be provided by the turret-less Sturmgeschütz assault gun, which mounted a short-barrelled gun on a Panzer III chassis.
Development
, Krupp, MAN, and Rheinmetall all produced prototypes. Testing of these took place in 1936 and 1937, leading to the Daimler-Benz design being chosen for production. The first model of the Panzer III, the Ausführung A., came off the assembly line in May 1937; ten, two of which were unarmed, were produced in that year. Mass production of the Ausf. F version began in 1939. Between 1937 and 1940, attempts were made to standardize parts between Krupp's Panzer IV and Daimler-Benz's Panzer III.Much of the early development work on the Panzer III was a quest for a suitable suspension. Several varieties of leaf-spring suspensions were tried on Ausf. A through Ausf. D, usually using eight relatively small-diameter road wheels before the torsion-bar suspension of the Ausf. E was standardized, using the six road wheel design that became standard. The Panzer III, along with the Soviet KV heavy tank, was one of the early tanks to use this suspension design first seen on the Stridsvagn L-60 a few years earlier.
A distinct feature of the Panzer III, influenced by the British Vickers Medium Mark I tank, was the three-man turret. This meant that the commander was not distracted with another role in the tank and could fully concentrate on maintaining awareness of the situation and directing the tank. Most tanks of the time did not have this capability, providing the Panzer III with a combat advantage versus such tanks. For example, the French Somua S-35's turret was manned only by the commander, and the Soviet T-34 originally had a two-man turret crew. Unlike the Panzer IV, the Panzer III had no turret basket, merely a foot rest platform for the gunner.
The Panzer III was intended as the primary battle tank of the German forces. However, on the Eastern front, the Panzer III proved to be inferior in both armour and firepower to the Soviet KV-1 heavy tanks and T-34 medium tanks. In response, the Panzer III was up-gunned to the 5 cm KwK 39, a longer, more powerful gun, and received more armour but still was at disadvantage compared with the Soviet tank designs. As a result, production of self-propelled anti-tank guns, as well as the up-gunning of the Panzer IV was initiated.
In 1942, the final version of the Panzer III, the Ausf. N, was created with a KwK 37 L/24 cannon, the same short-barreled low-velocity gun used for the initial models of the Panzer IV and designed for anti-infantry and close-support work. For defensive purposes, the Ausf. N was equipped with rounds of HEAT ammunition that could penetrate of armour depending on the round's variant, but these were strictly used for self-defence.
Armour
The Panzer III Ausf. A through C had of rolled homogeneous armour on all sides with on the top and on the bottom. This was quickly determined to be insufficient, and was upgraded to on the front, sides and rear in the Ausf. D, E, F, and G models, with the H model having a second layer of face-hardened steel applied to the front and rear hull. The Ausf. J model had a solid plate on the front and rear, while the Ausf. J¹, L, and M models had an additional layer of offset homogeneous steel plate on the front hull and turret, with the M model having an additional Schürzen spaced armour on the hull sides, and on the turret sides and rear. This additional frontal armor gave the Panzer III frontal protection from many light and medium Allied and Soviet anti-tank guns at all but close ranges. However, the sides were still vulnerable to many enemy weapons, including anti-tank rifles at close ranges.Armament
The Panzer III was intended to fight other tanks; in the initial design stage a gun was specified. However, the infantry at the time were being equipped with the PaK 36, and it was thought that, in the interest of standardization, the tanks should carry the same armament. As a compromise, the turret ring was made large enough to accommodate a gun should a future upgrade be required. This single decision later assured the Panzer III a prolonged life in the German Army.The Ausf. A to early Ausf. G were equipped with a 3.7 cm KwK 36 L/45, which proved adequate during the campaigns of 1939 and 1940. In response to increasingly better armed and armored opponents, the later Ausf. F to Ausf. J were upgraded with the 5 cm KwK 38 L/42, and the Ausf. J¹ to M with the longer 5 cm KwK 39 L/60 gun.
By 1942, the Panzer IV was becoming Germany's main medium tank because of its better upgrade potential. The Panzer III remained in production as a close support vehicle. The Ausf. N model mounted a low-velocity 7.5 cm KwK 37 L/24 gun - these guns had originally been fitted to older Panzer IV Ausf A to F1 models and had been placed in storage when those tanks had also been up armed to longer versions of the 75 mm gun.
All early models up to and including the Ausf. G had two 7,92 x 57 mm| MG 34 machine guns mounted coaxially with the 37 mm main gun and a similar weapon in a hull mount. Models from the Ausf. F and later, upgraded or built with a 5 or 7.5 cm main gun, had a single coaxial MG 34 and the hull MG34.
A single experimental Ausf. L was fitted with a 75/55mm tapered bore Waffe 0725 cannon. The vehicle was designated Panzer III Ausf L mit Waffe 0725.
Mobility
The Panzer III Ausf. A to D were powered by a, 12-cylinder Maybach HL108 TR engine, giving a top speed of. All later models were powered by the, 12-cylinder Maybach HL 120 TRM engine. Regulated top speed varied, depending on the transmission and weight, but was around.The fuel capacity was in Ausf A-D, in Ausf. E-G and in all later models. Road range on the main tank was in Ausf. A-J; the heavier later models had a reduced range of. Cross-country range was in all versions.
Combat history
The Panzer III was used in the German campaigns in Poland, in France, in the Soviet Union, and in North Africa. Many were still in combat service against Western Allied forces in 1944-1945: at Anzio in Italy, in Normandy, in Operation Market Garden in the Netherlands and in East Prussia against the Red Army. A sizeable number of Panzer IIIs also remained as armoured reserves in German-occupied Norway and some saw action, alongside Panzer IVs, in the Lapland War against Finland in the fall of 1944.In both the Polish and French campaigns, the Panzer III formed a small part of the German armoured forces. Only a few hundred Panzer III Ausf. As to Fs were available in these two campaigns, with most being armed with the main gun. They were the best medium tank available to the German military at the period of time.
Aside from use in Europe, the Panzer III also saw service in North Africa with Erwin Rommel's renowned Afrika Korps from early 1941. Most of the Panzer IIIs with the Afrika Korps were equipped with the KwK 38 L/42 50mm tank gun, with a small number possessing the older 37mm main gun of earlier variants. The Panzer IIIs of Rommel's troops were capable of fighting against British Crusader cruiser and US-supplied M3 Stuart light tanks with positive outcomes, although they did less effectively against heavily armoured Matilda II infantry tanks and the American M3 Lee/Grant medium tanks. In particular, the 75mm hull-mounted gun of the Lee/Grant tank could easily destroy a Panzer III far beyond the latter's own effective firing range, as did the similarly equipped M4 Sherman, which first saw combat with British forces in North Africa in October 1942.
Around the time of the beginning of Operation Barbarossa in the summer of 1941, the Panzer III was, numerically, the most important German tank on the frontline. At this time period, the majority of the available tanks for the invading German military had the KwK 38 L/42 50mm cannon. Initially, the most numerous Soviet tanks the Germans encountered at the start of the invasion were older T-26 light infantry and BT class of cruiser tanks. This fact, together with superior German tactical and strategic skills in armoured clashes, sufficient quality crew training, and the generally-good ergonomics of the Panzer III, all contributed to a favourable kill-loss ratio of approximately 6:1 for German tanks of all types in 1941. However, the Panzer IIIs were significantly outclassed by the Soviet T-34 medium and KV series of heavy tanks, the former of which was gradually encountered in greater numbers by the German forces as the invasion progressed, although initial T-34 models suffered from their cramped two-man turret, weak optics and poor vision devices.
File:Bundesarchiv Bild 101III-Zschaeckel-208-25, Schlacht um Kursk, Panzer III.jpg|thumb|right|The crew of a Panzer III of the 2nd SS Panzer Division Das Reich rests during a lull in the Battle of Kursk on the Eastern Front.
With the appearance of the T-34 and KV-1/-2 tanks, rearming the Panzer III with a longer-barrelled and more powerful gun was prioritised. The T-34 was generally invulnerable in frontal combat engagements with the Panzer III until the 50 mm KwK 39 L/60 tank gun was introduced on the Panzer III Ausf. J beginning in the spring of 1942. This could penetrate the T-34's heavy sloped armour frontally at ranges under. Against the KV class of heavy breakthrough tanks, the Panzer III was a significant threat if it was armed with special high-velocity tungsten-tipped armour-piercing rounds. In addition, to counter enemy anti-tank rifles, starting from 1943, the Ausf. L version began the use of spaced armour sideskirts and screens around the turret and on the vulnerable hull-sides. However, due to the introduction of the upgunned and better armoured Panzer IV, the Panzer III was, after the German defeat at the Battle of Kursk in the summer of 1943, relegated to secondary/minor combat roles, such as tank-training, and it was finally replaced as the main German medium tank by the Panzer IV and the Panzer V Panther.
The Panzer III's strong, reliable and durable chassis was the basis for the turretless Sturmgeschütz III assault gun/tank destroyer, one of the most successful self-propelled guns of the war, as well as being the single most-produced German armoured fighting vehicle design of World War II.
By the end of the war in 1945, the Panzer III saw almost no frontline use, and many of them had been returned to the few remaining armaments/tank factories for conversion into ammunition carriers or recovery vehicles. A few other variants of the Panzer III were also experimented on and produced by German industries towards the last phases of the war, but few were mass-produced or even saw action against the encroaching enemy forces of the Americans, British and Soviets.