Panthers were supplied to form Panzer Abteilung 51 (Tank Battalion 51) on 9 January, and then Pz.Abt. 52 on 6 February 1943.
The first production Panther tanks were plagued with mechanical problems. The engine was dangerously prone to overheating and suffered from connecting rod or bearing failures. Gasoline leaks from the fuel pump or carburetor, as well as motor oil leaks from gaskets easily produced fires in the engine compartment; several were destroyed in such fires. Transmission and final drive breakdowns were the most common and difficult to repair. A large list of other problems were detected in these early Panthers, and so from April through May 1943 all Panthers were shipped to Falkensee and Nürnburg for a major rebuilding program. This did not correct all of the problems, so a second program was started at Grafenwöhr and Erlangen in June 1943.
Albert Speer recounts in his autobiography Inside the Third Reich
Since the Tiger had originally been designed to weigh fifty tons but as a result of Hitler’s demands had gone up to seventy five tons, we decided to develop a new thirty ton tank whose very name, Panther, was to signify greater agility. Though light in weight, its motor was to be the same as the Tiger’s, which meant it could develop superior speed. But in the course of a year Hitler once again insisted on clapping so much armor on it, as well as larger guns, that it ultimately reached forty eight tons, the original weight of the Tiger
The first four Panthers underwent extensive tests at Grafenwöhr and Kummersdorf during late January and early February 1943, to be joined by further vehicles over the next few weeks. However, these tests – carried out by the crews of two new armoured units, the 51st and 52nd Panzer Battalions – revealed numerous minor design faults, as well as shoddy standards of manufacture. The gun, for example, could not be elevated or depressed to the specified degrees, while the corners of the turret often struck the closed driver’s and radio operator’s hatches on the hull roof. Furthermore, the vehicle’s final drive chains tended to break, its transmission frequently broke down, its motors often caught fire and its fuel pumps regularly failed. The unseemly haste to rush the vehicle into general production had resulted, inevitably, in myriad teething problems.
During February 1943, despite these problems, MAN delivered a further 11 completed Panthers to the proving grounds, while Daimler-Benz completed its first six Panthers and MNH one further vehicle. By 28 February 1943, therefore, the Germans had delivered 22 Model D tanks to the two new Panther battalions. Thereafter, newly produced Panthers featured a fixed radius steering gear instead of the clutch-brake steering gear fitted in the first 22 Panthers. During March, Daimler-Benz, MAN, and MNH delivered 58 Model D Panthers to the Army, while Henschel completed its first ten tanks, so that by the end of the month the Germans had 90 such tanks on strength. But as yet the Germans had not passed a single Model D tank as combat-ready since the early trials had identified 45 modifications that needed to be made before the tank could be used in battle. At this time, the High Command believed that the Panther would make a decisive contribution to the strategic victory that the planned German summer 1943 offensive in the East was expected to achieve. During early April, however, the Army concluded that before this could happen it had to rebuild its completed Panthers to rectify the faults identified during the early field trials.
The Germans, however, remained anxious that the modification work should not slow down the rate of completion of the part-assembled Panther tanks already on the production lines. Consequently, the four firms then producing Panthers did not take back the 90 vehicles already completed for modification work, but instead continued manufacturing Model D vehicles according to the original design despite its known faults. Only after 160 incomplete tanks had been finished would the Germans send them to the DEMAG factory at Falkensee for postproduction modification work. In the interim, the 90 tanks already delivered would remain with the 51st and 52nd Panzer Battalions for training purposes and would only be dispatched to Falkensee for modification once the subsequent 160 completed Panthers had been rebuilt at DEMAG. The rebuilding work undertaken by the latter firm during April and May included major modifications to the engine compartment, adjustment to the steering gears, suspension, final drives and transmission. Although the German firms completed these remaining 160 Panthers essentially to the original design, they did at least make one modification to them. From April 1943 the factories outfitted new vehicles with thin Schürzen armoured side skirts to protect the relatively vulnerable tracks and hull sides from Soviet anti-tank rifles.
By early May, frenzied German production had delivered the first batch of 250 Model D tanks to the proving grounds. In all subsequent construction, from vehicle 251 onwards, the assembly plants outfitted new Panthers with the 700bhp Maybach HL230 P30 engine instead of the original HL210. While this added power did not increase the overall speed of the Model D Panther, it did improve acceleration and cross-country performance; above all, it eased the excessive strain frequently imposed on HL210-equipped tanks and thus went some way to improving the mechanical reliability of the tank.
Despite the extensive DEMAG rebuild programme, further field trials undertaken during May with the first 250 Panthers continued to reveal serious problems. Consequently, from June new HL230-engined tanks underwent further modification, while existing vehicles were modified at Grafenwöhr. One of these alterations involved strengthening the tank’s over-strained road wheels by fitting additional rivets between the existing 16 rim bolts. In addition, these vehicles underwent further alterations to their transmissions. Meanwhile, back at the factories, some of the new HL230-engined tanks completed during this month emerged without the characteristic set of three smoke-grenade launchers on each side of the turret, although Henschel-manufactured tanks still had them into June. The factories discontinued this feature because field trials had shown that surprise attacks by enemy small-arms fire often inadvertently triggered the smoke grenades when “the vehicle still had its hatches open, and the smoke soon incapacitated the crew. By 31 May, the Army had received 250 HL210-engined and 118 HL230-engined Model D tanks. However, many Panthers remained non-operational either because of the faults identified above or because they were being rebuilt and thus could not be deployed at the front for the imminent German summer offensive. Indeed, it was not until further modification work had been completed in late June, that the Germans managed to redeploy 200 Panthers to the Soviet Union for the now much-delayed German Citadel offensive.
The Panther made its operational debut on 5July 1943 during Citadel, in which the High Command expected the 200 Panthers to contribute decisively to the stunning victory it expected to secure. Citadel involved a double-pronged German attack from the northern and southern shoulders of a large Soviet salient that jutted west into the German lines around Kursk. The Soviets, however, had detected the German preparations and had built up awesome defensive strength to resist the attack. This build-up did little to perturb German confidence; after all, given the widespread German belief in the combat power of the Panther tank, they simply reckoned that the greater the Soviet force deployed against them, the greater the victory they would achieve once their double pincers had linked up at Kursk to form the largest encirclement yet achieved in the war. The Panther units employed in Citadel the 51st and 52nd Panzer Battalions – each fielded four companies of 22 Panthers, plus a further eight Model D tanks, to make a total unit strength 96 Panthers each. The two battalions came under the control of Major von Lauchert’s improvised brigade staff, itself equipped with eight Panthers, which fought alongside the Panzergrenadier Division Grossdeutschland as part of the southern prong of the attack.
Major problems, however, dogged the contribution made by the Panthers even before the offensive began. Because the two Panther-equipped tank battalions were deployed in the East just a few days before Citadel commenced, the units had little time for acclimatisation training in situ. Moreover, 16 tanks broke down on the short journey between disembarking from their transportation trains and reaching the front. Things went little better once the offensive began. In the face of fanatical Soviet resistance, large numbers of Panthers fell by the wayside. By 7July 1943, the third day of the offensive, just 40 of the 184 Panthers that started Citadel were still operational, while by 10 July just 10 of them remained in front-line service. Of the remaining 174 Panthers that had begun Citadel, 23 had been lost due to ‘brewing up’ after enemy hits on their relatively vulnerable side armour, while two had burned after engine fires before combat had even been joined. Another 44 Panthers were being repaired after mechanical failure and a further 56 because of damage caused by enemy fire or anti-tank mines. German workshops had already repaired a further 40 Panthers with minor damage or mechanical problems, but these were still on the way to rejoin the brigade. The remaining nine tanks, which had been abandoned on the battlefield after sustaining damage, had still to be recovered.
The much vaunted debut of the Panther had proven to be a debacle. Admittedly the Germans could discern a few glimmers of hope from this serious setback. Post-combat reports from the fighting experienced at Kursk confirmed the anticipated combat power of the 7.5cm Panther gun; this weapon had accounted for many T-34 tanks, often at ranges of 1500m or more. In addition, the Panther’s two machine guns had proven to be very reliable, with a very low incidence of jamming. However, most of the other aspects of the Panther mentioned in post-combat reports proved unfavourable. Troops observed, for example, that the Panther’s turret grenade launchers soon became inoperative due to enemy small arms fire, that its engine regularly broke down, that its over-stressed transmission often failed, and that its road wheels sometimes fractured. In addition, crews complained about fuel pump leaks that often led to dangerous fires starting inside the tank, the dangerous build-up of gun exhaust gases inside the turret, and the problems caused when driving rain entered the turret through the mantlet binocular periscope. Further modifications were needed, the Germans concluded, before the Panther realised the potential it clearly possessed to be a potent tank on the future battlefield.
Meanwhile back in Germany, even as Citadel unfolded, the factories introduced further production simplifications designed to raise production rates. The new Model D Panthers that rolled off the production lines that month no longer had the circular communications hatch fitted to the left-hand side of the turret, and had only one headlamp (on the left) instead of two. From late July, in response to the lessons gathered at Kursk, some newly completed Model D tanks featured more resilient road wheels fitted with 24 rim bolts instead of 16. In addition, these vehicles sported an additional ring mounted on the commander’s cupola onto which an anti-aircraft machine gun could be fitted. Yet at this time Panther production still remained hurried and poorly organised; consequently some of the 115 Panthers produced during August did not incorporate these modifications because of over-hasty production or shortages of parts at the factories.
Most of the 115 new Model D Panthers delivered in August – some 96 vehicles – arrived in the East at the end of the month to completely re-equip the 51st Panzer Battalion, which in the aftermath of Citadel had given up its few remaining tanks to reinforce the remnants of the 52nd Battalion. Between them these battalions had suffered 58 Panthers lost by the end of Citadel, excluding another 50 in short-term repair. Yet far worse was to transpire. In the desperate defensive battles the Germans fought to resist the Soviet counter-offensives that erupted over the following six weeks these battalions lost a further 98 Panthers; consequently, fewer than 44 of the original Model D tanks dispatched to Citadel remained operational by early September.