Panzer IV

Origins The Panzer IV was the brainchild of the German general and innovative armoured warfare theorist Heinz Guderian. In concept, it was intended to be a support tank for use against enemy anti-tank guns and fortifications. Ideally, each tank battalion in a panzer division was to have three medium companies of Panzer IIIs and one heavy company of Panzer IVs. On 11 January 1934, the German army wrote the specifications for a "medium tractor", and issued them to a number of defense companies. To support the Panzer III, which would be armed with a anti-tank gun, the new vehicle would have a short-barreled, howitzer-like as its main gun, and was allotted a weight limit of . Development was carried out under the name ("accompanying vehicle"), or BW, to disguise its actual purpose, given that Germany was still theoretically bound by the Treaty of Versailles ban on tanks. MAN, Krupp, and Rheinmetall-Borsig each developed prototypes, The chassis had originally been designed with a six-wheeled interleaved-road wheel suspension (as already adopted for German half-tracks), but the German Army amended this to a torsion bar system. Permitting greater vertical deflection of the road wheels, this was intended to improve performance and crew comfort both on- and off-road. However, due to the urgent requirement for the new tank, neither proposal was adopted, and Krupp instead equipped it with a simple leaf spring double-bogie suspension, with eight rubber-rimmed road wheels per side. The prototype had a crew of five; the hull contained the engine bay to the rear, with the driver and radio operator, who doubled as the hull machine gunner, seated at the front-left and front-right, respectively. In the turret, the tank commander sat beneath his roof hatch, while the gunner was situated to the left of the gun breech and the loader to the right. The torque shaft ran from the rear engine to the transmission box in the front hull between the driver and radio operator. To keep the shaft clear of the rotary base junction, which provided electrical power to the turret including the motor to turn it, the turret was offset to the left of the chassis centre line, and the engine was moved to the right. Due to the asymmetric layout, the right side of the tank contained the bulk of its stowage volume, which was taken up by ready-use ammunition lockers. Ausf. A to Ausf. F1 The first mass-produced version of the Panzer IV was the  A (abbreviated to Ausf. A, meaning "Variant A"), in 1936. It was powered by a Maybach HL108 TR, producing , and used the SGR 75 transmission with five forward gears and one reverse, achieving a maximum road speed of . As main armament, the vehicle mounted the short-barreled, howitzer-like 37 7.5 cm KwK 37 tank gun, 24 calibres in length, which was a low-velocity weapon mainly designed to fire high-explosive shells. Against armoured targets, firing the (armour-piercing shell) at the KwK 37 could penetrate , inclined at 30 degrees, at ranges of up to . A MG 34 machine gun was mounted coaxially with the main weapon in the turret, while a second machine gun of the same type was mounted in the front plate of the hull. The Ausf. A was protected by of steel armour on the front plate of the chassis, and on the turret. This was only capable of stopping artillery fragments, small-arms fire, and light anti-tank projectiles. A total of 35 A versions were produced. The glacis plate was augmented to a maximum thickness of , Forty-two Panzer IV Ausf. Bs were manufactured. This saw the turret armour increased to , which brought the tank's weight to . thick external mantlet. In October 1940, the Ausf. E was introduced. This had of armour on the bow plate, while a appliqué steel plate was added to the glacis as an interim measure. A new driver's visor, adopted from the Sturmgeschütz III was installed on the hull front plate. A new commander's cupola, adopted from the Panzer III Ausf. G, was relocated forward on the turret eliminating the bulge underneath the cupola. Older model Panzer IV tanks were retrofitted with these features when returned to the manufacturer for servicing. 206 Ausf. Es were produced between October 1940 and April 1941. The main engine exhaust muffler was shortened and a compact auxiliary generator muffler was mounted to its left. The designation Ausf. F was changed in the meantime to Ausf. F1, after the distinct new model, the Ausf. F2, appeared. A total of 471 Ausf. F (later temporarily called F1) tanks were produced from April 1941 to March 1942. Within months, the shock of encountering the Soviet T-34 medium and KV-1 heavy tanks necessitated a new, much more powerful tank gun. In November 1941, the decision to up-gun the Panzer IV to the gun was dropped, and instead Krupp was contracted in a joint development to modify Rheinmetall's pending anti-tank gun design, later known as 7.5 cm Pak 40 L/46. Because the recoil length was too great for the tank's turret, the recoil mechanism and chamber were shortened. This resulted in the KwK 40 L/43. When the new KwK 40 was loaded with the Pzgr. 39 armour-piercing shell, the new gun fired the AP shell at some , a substantial 74% increase over the howitzer-like KwK 37 L/24 gun's muzzle velocity. Firing the 39, the KwK 40 L/43 could penetrate of steel armour at a range of . The longer 7.5 cm guns made the vehicle nose-heavy to such an extent that the forward suspension springs were under constant compression. This resulted in the tank tending to sway even when no steering was being applied, an effect compounded by the introduction of the H in March 1943. heavy tanks The Ausf. F tanks that received the new, longer, KwK 40 L/43 gun were temporarily named Ausf. F2 (with the designation Sd.Kfz. 161/1). The tank increased in weight to . Differences between the Ausf. F1 and the Ausf. F2 were mainly associated with the change in armament, including an altered gun mantlet, internal travel lock for the main weapon, new gun cradle, new 5f optic for the L/43 weapon, modified ammunition stowage, and discontinuing of the in favor of turret mounted . Three months after beginning production, the Panzer IV Ausf. F2 was renamed Ausf. G. During its production run from March 1942 to June 1943, the Panzer IV Ausf. G went through further modifications, including another armour upgrade, which consisted of a face-hardened appliqué steel plate welded (later bolted) to the glacis—in total, so that frontal armour was now thick. This decision to increase frontal armour was favorably received according to troop reports on 8 November 1942, despite technical problems with the driving system due to added weight. At this point, it was decided that 50% of Panzer IV production would be fitted with thick additional armour plates. On 5 January 1943, Hitler decided that all Panzer IVs should have frontal armour. To simplify production, the vision ports on either side of the turret and the loader's forward vision port in the turret front were removed, while a rack for two spare road wheels was installed on the track guard on the left side of the hull. Complementing this, brackets for seven spare track links were added to the glacis plate. For operation in high temperatures, the engine's ventilation was improved by creating slits over the engine deck to the rear of the chassis, and cold weather performance was boosted by adding a device to heat the engine's coolant, as well as a starter fluid injector. A new light replaced the original headlight and the signal port on the turret was removed. On 19 March 1943, the first Panzer IV with Schürzen skirts on its sides and turret was exhibited. The double hatch for the commander's cupola was replaced by a single round hatch from very late model Ausf. G. and the cupola was up-armoured from to . In April 1943, the KwK 40 L/43 was replaced by the longer KwK 40 L/48 gun, with a redesigned multi-baffle muzzle brake with improved recoil efficiency. The longer L/48 resulted in the introduction of the Turmzielfernrohr 5f/1 optic. in Saumur, France, with its distinctive anti-magnetic mine coating, turret skirts, and wire-mesh side-skirts The next version, the Ausf. H, began production in June 1943 To prevent adhesion of magnetic anti-tank mines, which the Germans feared would be used in large numbers by the Allies, paste was added to all the vertical surfaces of the tank's armour. The turret roof was reinforced from to and segments. This resulted in the elimination of the vision ports located on the hull side, These modifications meant that the tank's weight increased to . In spite of a new six-speed SSG 77 transmission adopted from the Panzer III, top speed dropped to as low as on cross country terrain. An experimental version of the Ausf H was fitted with a hydrostatic transmission but was not put into production. The electric generator that powered the tank's turret traverse was removed, so the turret had to be rotated manually. The turret traversing mechanism was modified and fitted with a second gear which made hand-operation easier when the vehicle was on sloping terrain. On reasonably level ground, hand operation at 4 seconds to traverse to 12.5° and 29.5 seconds to traverse to 120° was achieved. The remaining pistol and vision ports on the turret side hatches were removed, and the engine's radiator housing was simplified by changing the slanted sides to straight sides. In addition, the cylindrical muffler was replaced by two flame-suppressing mufflers. In June 1944 Wa Prüf 6 had decided that because bomb damage at Panzerfirma Krupp in Essen had seriously jeopardized tank production, all plates which should have been face-hardened for the Panzer IV were instead made with rolled homogeneous armour plate. and the number of return rollers was reduced from four to three to further speed-up production. In a bid to augment the Panzer IV's firepower, an attempt was made to mate a turret – carrying the longer L/70 tank gun from the developing Panther Ausf. F tank design, and partly developed by Rheinmetall from early 1944 onwards – to a Panzer IV hull. This failed and confirmed that the chassis had reached the limit of its adaptability in both weight and available volume. ==Production==

The Panzer IV was originally intended to be used only on a limited scale, so initially Krupp was its sole manufacturer. Prior to the Polish campaign, only 217 Panzer IVs had been produced: 35 Ausf. A; 42 Ausf. B; and 140 Ausf. C; in 1941, production was extended to Vogtländische Maschinenfabrik ("VOMAG") (located in the city of Plauen) and the Nibelungenwerk in the Austrian city of St. Valentin. With the slow collapse of German industry under pressure from Allied air and ground offensives—in October 1944 the Nibelungenwerk factory was severely damaged during a bombing raid—by March and April 1945, production had fallen to pre-1942 levels, with only around 55 tanks per month coming off the assembly lines. ==Export==

The Panzer IV was one of the most widely exported German tanks of the Second World War. In 1942, Germany delivered 11 tanks to Romania and 32 to Hungary, many of which were lost on the Eastern Front between the final months of 1942 and the beginning of 1943 during the battles around Stalingrad, at which the Hungarian and Romanian troops there were almost annihilated by the attacking Soviet forces. Romania received approximately 120 Panzer IV tanks of different models throughout the entire war. To arm Bulgaria, Germany supplied 46 or 91 Panzer IVs, and offered Italy 12 tanks to form the nucleus of a new Italian Army armoured division. These were used to train Italian tank crews while the-then Italian leader Benito Mussolini was deposed shortly after the Allied conquest of Sicily but were then retaken by Germany during its occupation of Italy in mid-1943. Finland bought 30 but only received 15 in 1944 and in the same year a second batch of 62 In total, 297 Panzer IVs of all models were delivered to Germany's allies. ==Combat history==

The Panzer IV was the only German tank to remain in both production and combat throughout World War II, and measured over the entire war it comprised 30% of the s total tank strength. Although in service by early 1939, in time for the occupation of Czechoslovakia, at the start of the war the majority of German armour was made up of obsolete Panzer Is and Panzer IIs. The Panzer I in particular had already proved inferior to Soviet tanks, such as the T-26, during the Spanish Civil War. Poland, Western Front and North Africa (1939–1942) When Germany invaded Poland on 1 September 1939, its armoured corps was composed of 1,445 Panzer Is, 1,223 Panzer IIs, 98 Panzer IIIs and 211 Panzer IVs; the more modern vehicles amounted to less than 10% of Germany's armoured strength. The 1st Panzer Division had a roughly equal balance of types, with 17 Panzer Is, 18 Panzer IIs, 28 Panzer IIIs, and 14 Panzer IVs per battalion. The remaining panzer divisions were heavy with obsolete models, equipped as they were with 34 Panzer Is, 33 Panzer IIs, 5 Panzer IIIs, and 6 Panzer IVs per battalion. Although the Polish Army possessed less than 200 tanks capable of penetrating the German light tanks, Polish anti-tank guns proved more of a threat, reinforcing German faith in the value of the close-support Panzer IV. passing a burning German Panzer IV during Operation Crusader, late 1941 Despite increased production of the medium Panzer IIIs and IVs prior to the German invasion of France on 10 May 1940, the majority of German tanks were still light types. According to Heinz Guderian, the Wehrmacht invaded France with 523 Panzer Is, 955 Panzer IIs, 349 Panzer IIIs, 278 Panzer IVs, 106 Panzer 35(t)s and 228 Panzer 38(t)s. Through the use of tactical radios and superior tactics, as well as greater mobility generally, the Germans were able to outmaneuver and defeat French and British armour. However, Panzer IVs armed with the KwK 37 L/24 tank gun found it difficult to engage French tanks such as the Somua S35 and Char B1. Although the Panzer IV was deployed to North Africa with the German Afrika Korps, until the longer gun variant began production, the tank was outperformed by the Panzer III with respect to armour penetration. Both the Panzer III and IV had difficulty in penetrating the British Matilda II's thick armour, while the Matilda's 40-mm QF 2 pounder gun could knock out either German tank; the Matilda II's major disadvantage was its low speed. By August 1942, Rommel had only received 27 Panzer IV Ausf. F2s, armed with the L/43 gun, which he deployed to spearhead his armoured offensives. Although more of these tanks arrived in North Africa between August and October 1942, their numbers were insignificant compared to the amount of matériel shipped to British forces. The Panzer IV also took part in the invasions of Yugoslavia and Greece in early 1941. Eastern Front (1941–1945) carrying skirting operating on the Eastern Front in the USSR, 1944 With the launching of Operation Barbarossa on 22 June 1941, the unanticipated appearance of the KV-1 and T-34 tanks prompted an upgrade of the Panzer IV's gun to a longer, high-velocity 75 mm gun suitable for anti-tank use. This meant that it could now penetrate the T-34 at ranges of up to at any angle. The 75 mm KwK 40 L/43 gun on the Panzer IV could penetrate a T-34 at a variety of impact angles beyond range and up to . Shipment of the first model to mount the new gun, the Ausf. F2, began in spring 1942, and by the summer offensive there were around 135 Panzer IVs with the L/43 tank gun available. At the time, these were the only German tanks that could defeat T-34 or KV-1 with sheer firepower. They played a crucial role in the events that unfolded between June 1942 and March 1943, and the Panzer IV became the mainstay of the German panzer divisions. Although in service by late September 1942, the Tiger I was not yet numerous enough to make an impact and suffered from serious teething problems, while the Panther was not delivered to German units in the Soviet Union until May 1943. The extent of German reliance on the Panzer IV during this period is reflected by their losses; 502 were destroyed on the Eastern Front in 1942. The Panzer IV continued to play an important role during operations in 1943, including at the Battle of Kursk. Newer types, such as the Panther, were still experiencing crippling reliability problems that restricted their combat efficiency, so much of the effort fell to the 841 Panzer IVs that took part in the battle. Throughout 1943, the German army lost 2,352 Panzer IVs on the Eastern Front; some divisions were reduced to 12–18 tanks by the end of the year. Nevertheless, due to a shortage of replacement Panther tanks, the Panzer IV continued to form the core of Germany's armoured divisions, including elite units such as the II SS Panzer Corps, through 1944. In January 1945, 287 Panzer IVs were lost on the Eastern Front. It is estimated that combat against Soviet forces accounted for 6,153 Panzer IVs, or about 75% of all Panzer IV losses during the war. Western Front (1944–45) " near the Arc de Triomphe in Paris, 1942. Panzer IVs comprised around half of the available German tank strength on the Western Front prior to the Allied invasion of Normandy on 6 June 1944. Most of the 11 Panzer divisions that saw action in Normandy initially contained an armoured regiment of one battalion of Panzer IVs and another of Panthers, for a total of around 160 tanks, although Waffen-SS Panzer divisions were generally larger and better equipped than their counterparts. Regular upgrades to the Panzer IV had helped to maintain its reputation as a formidable opponent. The side skirt armour could predetonate shaped charge anti-tank weapons such as the British PIAT, but could be pulled away by rugged terrain. German tankers in all theaters were "frustrated by the way these skirts were easily torn off when going through dense brush". Against earlier-model Panzer IVs, it could hold its own, but with its 75 mm M3 gun, struggled against the late-model Panzer IV. The late-model Panzer IV's frontal hull armour could easily withstand hits from the weapon on the Sherman at normal combat ranges, though the turret remained vulnerable. The British up-gunned the Sherman with their highly effective 76 mm QF 17-pounder anti-tank gun, resulting in the Firefly; although this was the only Allied tank capable of dealing with all current German tanks at normal combat ranges, few (342) were available in time for the Normandy invasion. which was enough to make good any losses. A second British tank equipped with the 17-pdr gun, the Cruiser Mk VIII Challenger, could not participate in the initial landings having to wait for port facilities to be ready to land. It was not until July 1944 that American Shermans fitted with the 76 mm gun M1 gun achieved a parity in firepower with the Panzer IV. By 29 August 1944, as the last surviving German troops of Fifth Panzer Army and Seventh Army began retreating towards Germany, the twin cataclysms of the Falaise Pocket and the Seine crossing cost the Wehrmacht dearly. Of the 2,300 tanks and assault guns it had committed to Normandy (including around 750 Panzer IVs Field Marshal Walter Model reported to Hitler that his panzer divisions had remaining, on average, five or six tanks each. The Panzer IVs that took part were survivors of the battles in France between June and September 1944, with around 260 additional Panzer IV Ausf. Js issued as reinforcements. Other users , Finland, in November 1944 Finland Finland bought 15 new Panzer IV Ausf. Js in 1944. The remainder of an order for 40 tanks and some StuG IIIs were not delivered and neither were necessary German tank instructors provided. The tanks arrived too late to see action against the Soviet Union but instead ended up being used against Nazi Germany during their withdrawal through Lapland. After the war, they served as training tanks and one portrayed a Soviet KV-1 tank in the movie The Unknown Soldier in 1955. The additional weight, going from the 18.4 tons (Ausf. A) to about 25 tons (Ausf. J), of these modifications strained the simple leaf spring suspension. As a result, the Finnish Army often referred to the PzKpfw IV Ausf.J as the "shaker" for its rough ride, when compared to their StuG IIIs that, by comparison, had the much better torsion-bar suspension of the PzKpfw III. According to the Finnish, this not only affected general crew comfort, but also hampered the accurate aiming of the main gun whilst on the move. What exactly caused these "vibrations" that gave the PzKw IV Ausf. J such a bad name among Finnish tank crews remains somewhat unclear as it isn't mentioned in any German or Allied descriptions, but the inadequate leaf spring suspension and comparison with the very smooth ride of the StuG III seems to be the most likely cause. Bulgaria After 1945, Bulgaria incorporated its surviving Panzer IVs into defensive bunkers as strongpoints along its border with Turkey, along with Soviet T-34 turrets. This defensive line, known as the "Krali Marko Line", remained in use until the fall of communism in 1989. Spain Twenty Panzer IV Ausf. Hs and ten StuG III Ausf. Gs were supplied to Spain in December 1943, a small fraction of what Spain had originally asked for. The Panzer IV represented the best tank in Spanish service between 1944 and 1954, and was deployed along with T-26s and Panzer Is. Spain sold 17 Panzer IVs to Syria in 1967, with the remaining three left conserved. These can be found in Madrid, Burgos and Santovenia de Pisuerga (Valladolid). Romania Most of the tanks Romania had received were lost during combat between 1944 and 1945. These tanks, designated T4 in the army's inventory, were used by the Army's 2nd Armoured Regiment. On 9 May 1945, only two Panzer IVs were left. Romania received another 50 captured Panzer IV tanks from the Red Army after the end of the war. These tanks were of many different models and were in very bad shape A Soviet 12.7mm DShK machine gun on an anti-aircraft mount was retrofitted on the cupola. These ex-German tanks were used to shell Israeli settlements below the Golan Heights, together with Soviet-supplied T-34s, and were fired upon in 1965 during the Water War by Israeli Super Sherman and Centurion tanks. Panzer IVs also participated in 1973 Yom Kippur War, with some dug in as pillboxes. Several of Syria's Panzer IVs were captured by the Israeli Army and donated to the Yad La-Shiryon museum, which later traded an Ausf H from this collection to the American Armored Foundation Tank Museum in Danville, Virginia in exchange for an M5 Stuart. Turkey In addition, Turkey was a buyer, with 35 Panzer IVs received until 4 May 1944 in exchange for some chromium ore. Delivery began with the Ausf. G and probably went on with Ausf. H versions. Other sources state only 15 to 22 tanks were delivered in 1943, all of the Ausf G version. Ukraine In 2023, during the Russo-Ukrainian War, the wreckage of a Panzer IV, likely a former Syrian Army example, was discovered near Kreminna by Russian forces. The tank was fitted with BMP-2 treads, In December 1944 , the 1st GMR (Groupement Mobile de Reconnaissance) of the FFI (French Forces of the Interior), later called 'Escadron Autonome de Chars Besnier', was equipped with at least one Panzer IV. Reliability From an after-action report submitted by PzRgt 6 on 23 July 1941: (The workshop company added some further notes:) After that report from the units, the Inspector General of Armored Troops acknowledged this in a report, at 1944.05.06.: Der Generalinspekteur der Panzertruppen-Leitender Kraftfahrzeugoffizer-Bb Nr. 3177/44 ==Variants==

tank destroyer, based on the Panzer IV chassis, mounting the 75 mm Pak L/48 anti-tank gun infantry-support gun In keeping with the wartime German design expediencies of mounting an existing anti-tank gun on a convenient chassis to give mobility, several tank destroyers and infantry support guns were built around the Panzer IV hull. Both the , initially armed with the L/48 tank gun, and the Krupp-manufactured , which was the casemate of the mounted on the body of the Panzer IV, proved highly effective in defense. Cheaper and faster to construct than tanks, but with the disadvantage of a very limited gun traverse, around 1,980 IVs and 1,140 IVs were produced. Another tank destroyer, the Panzer IV/70, used the same basic 75-millimeter L/70 gun that was mounted on the Panther. The IV (Pz. Bef. Wg. IV) was a command tank. This conversion entailed the installation of additional radio sets with associated mounting racks, transformers, junction boxes, wiring, antennas and an auxiliary electrical generator. To make room for the new equipment, ammunition stowage was reduced from 87 to 72 rounds. The vehicle could coordinate with nearby armour, infantry or even aircraft. Seventeen were built on Ausf. J chassis in August and September 1944, The IV (Pz. Beob. Wg. IV) was an artillery observation vehicle built on the Panzer IV chassis. This, too, received new radio equipment and an electrical generator, installed in the left rear corner of the fighting compartment. worked in cooperation with Wespe and Hummel self-propelled artillery batteries. The (called "" by Allied intelligence) was an infantry-support self-propelled gun. These vehicles were primarily issued to four units (Numbers 216, 217, 218 and 219) and used during the battle of Kursk and in Italy in 1943. Two separate versions of the IV existed, one without a machine gun in the mantlet and one with a machine gun mounted on the mantlet of the casemate. Furthermore, a artillery gun was mounted in an experimental demountable turret on a Panzer IV chassis. This variant was called the ("grasshopper"). Another 105 mm artillery/anti-tank prototype was the 10.5 cm K gepanzerte Selbstfahrlafette, nicknamed , made in two examples, both used in the Eastern Front. One caught fire, and the other one fought with success during Operation Barbarossa and Operation Blue; during Operation Blue, it fought in the Battle of Stalingrad. Four different self-propelled anti-aircraft vehicles were built on the Panzer IV hull. The ("moving van") was armed with a anti-aircraft cannon; 240 were built between 1944 and 1945. In late 1944 a new , the ("whirlwind"), was designed, with enough armour to protect the gun's crew in a rotating turret, armed with the anti-aircraft cannon system; at least 100 were manufactured. Sixty-five (out of an order for 100) similar vehicles with a single 37 mm anti-aircraft cannon were built named ("East wind"). This vehicle was designed to replace the . The final model was the IV , of which only five pilot vehicles were built. This vehicle featured an enclosed turret armed with twin Rheinmetall-Borsig MK 103 aircraft cannon. Although not a direct modification of the Panzer IV, some of its components, in conjunction with parts from the Panzer III, were used to make one of the most widely used self-propelled artillery chassis of the war—the III/IV. This chassis was the basis of the , of which 666 were built, and also the gun-armed tank destroyer, with 473 manufactured. To resupply self-propelled howitzers in the field, 150 ammunition carriers were manufactured on the III/IV chassis. 21 were converted from hulls returned for repair between October 1944 and January 1945. The conversion involved removing the turret and adding a wooden plank cover with an access hatch over the turret ring and the addition of a 2-ton jib crane and rigid towing bars. A rare variant was the Panzer IV . In 1944, Zahnradfabrik (ZF) Augsburg plant produced a prototype with an unusual drive concept. A Panzer IV Ausf. H tank received a fluid drive instead of the normal gearbox. Two oil pumps were installed behind the engine, which in turn drove two oil engines. An axial engine drive transmitted the power to the rear drive wheels via a reduction gear. Instead of the two steering levers, the driver had a crescent-shaped steering wheel with the steering movements of which two steering cylinders were operated, which in turn regulated the volume of the oil pumps and thus regulated the adjacent force on the two drive wheels. The only prototype built was not used and was shipped to America after the war to be subjected to driving tests. These finally had to be discontinued due to a lack of spare parts. The only surviving vehicle is now in United States Army Ordnance Training and Heritage Center in Virginia. Production models Variants based on chassis ==See also==