Monday, March 23, 2015
The development of the Panther "Schmalturm"
In the past an amount of confusion and misinterpretation has existed regarding the Panther "Schmalturm" (meaning "narrow turret"). Early sources, while recorded in good faith, were based on uncorroborated verbal reports and recollections. Gradually, each subsequent re-telling eclipsed this origin, and these details assumed the status of indisputable fact - without there being any intention to mislead. Only relatively recently have the original production and design records been reviewed, clarifying the situation.
The development of what has come to be known as the "Schmalturm" for the Panzerkampfwagen V Panther is inextricably linked with that of the Panther II, the Panther Ausf. F, the E-50 project and to a lesser degree, to the Tiger II. Due to problems evinced in the design of the original Panther turret, an improvement was sought. Naturally constraints affected the design, principally the retention of as many components and fittings as possible, the desire to maintain the size of the existing turret ring and to keep production costs and time to a minimum.
Evidence exists that as early as November 1943 efforts were being made to significantly redesign the turret of the Panther. The primary reasons for this were to improve the design of the gun mantlet to obviate the tendency of shots being deflected downwards through the thin armour of the hull roof and also to reduce the overall frontal area of the turret. Initial investigations into the new design were undertaken by Rheinmetall-Borsig, with the added requirement of incorporating a rangefinder into the turret. By March 1944 plans had been drawn up fulfilling these requirements, while keeping as many of the internal components unchanged from the Panther Ausf. A turret. This design was referred to as "Turm Panther 2 (schmale Blendenausfuehrung)", meaning "Panther 2 turret (narrow mantlet version) and also as "Turm - Panther (schmale Blende)". However, during spring 1944 the responsibility of continuing research on the new turret was re-assigned to Daimler-Benz by Waffen Prüfungsamt 6 (Weapon Testing Office 6, the Army Weapons Office department responsible for tank design). The reason behind this decision has still not become apparent. By this point, additional requirements had been stipulated; that a MG42 co-axial machine-gun be fitted in place of the (no longer produced) MG34, and that the turret be suitable for field installation of an infrared searchlight and scope for night-fighting, or command equipment (additional radio sets, etc.) to create a command tank.
The Daimler-Benz design, which appears to have been the origin of the (unofficial) "Schmalturm" designation, met the design requirements admirably. The official designation, recorded in a document dated 20 November 1944, was Panther-Turm Ausf. F. This turret was more heavily armoured than the previous model, yet slightly lighter. The frontal area of the turret was reduced, presenting a smaller silhouette to incoming fire. The wide curved gun mantlet of the earlier turret had been replaced with a conical shaped mantlet of the same "Saukopf" ("boar's head") design as that fitted to the Tiger II. A lower (and thus less vulnerable) commander's cupola was fitted. Less immediately obvious features were the inclusion of an escape hatch and pistol port in the rear face of the turret. The manufacturing time was reduced (for the turret itself, excluding armament and equipment) by some 30%-40% (in man-hours). Material usage was also conserved (an important consideration for Germany by this point in the war); the hatches, for example, were fabricated from the pieces of armour cut out of the turret to create the hatchways themselves.
The 7.5cm Kw.K 42 L/70 gun used in the existing Panther turret was retained after some redesign by Skodawerke, which resulted in modification of the cradle and recoil system. The designation for the new weapon was the 7.5cm Kw.K 44/1 L/70. Although photographs of the Versuchs-Schmalturm (experimental narrow turret) show a muzzle brake attached to the gun, there was no intention of fitting this on the production models, the recoil system being sufficient to manage the full recoil. A further development of the gun, termed the 7.5cm Kw.K 44/2 L/70 added a rapid reload mechanism to the breech. The recoil action ejected the spent shell case and loaded a new round from a clip of four. The rate of fire attainable by the weapon was a theoretical 40 rounds per minute. The three guns built to this specification underwent testing, but this had not progressed as far as being fitted in a tank.
In addition to a conventional telescopic gunsight a stereoscopic rangefinder was fitted in the turret roof. The effective range of tank guns was gradually increasing, which lead to a requirement for accurate rangefinding at longer ranges, so that the required muzzle elevation could be determined. At closer ranges (up to approximately 2000m) less precision was required due to the round's relatively flat trajectory. Efforts to combine a rangefinger and gunsight had failed, their requirements being too disparate. Chosen for inclusion in the design was a stereoscopic rangefinder (still under development by Zeiss, but nearing completion) where the range determined by the rangefinder was automatically transferred to the gunsight. The rangefinder was mounted in shock-absorbing supports so that its optics were not knocked out of alignment by the tanks movements or (survivable) incoming rounds. It was intended to install a stabilised periscopic gunsight once production had started, permitting the gunner to fire - or at least aim - on the move with better accuracy. These sights were being trialed, but these trials had not reached completion, and the sights were never fitted.
During early 1945 development continued apace, even while Germany was losing ground rapidly. Meetings in January and February began the development of mounting an 8.8cm gun in the Panther Schmalturm. After initial possibilities were considered, it was decided that the 8.8cm Kw.K 43 L/71 in use on the Tiger II should be used (albeit with necessary modifications), the stereoscopic rangefinder be retained, and that the stabilised gun sight should be fitted if possible. To facilitate the mounting and operation of the larger weapon, the turret ring required a 100mm increase in its diameter. The tank would have carried approximately 65-70 rounds of 8.8cm ammunition, 15 of which would have been carried in the turret. Progress on this project got as far as a wooden model mock-up before the end of the war. It had been anticipated that, if all went smoothly, production was to start during the last quarter of 1945.
Two prototype models of the 7.5cm Kw.K 44/1 L/70 armed Schmalturm were mounted on Panther Ausf. G bodies for evaluation. This configuration was to have formed the Panther Ausf. F, along with an increase in armour thickness for the hull roof (from 40-16mm, to 40-25mm), and other relatively minor modifications to the construction and systems. The Ausf. F was scheduled to have started production in March 1945 at the Daimler-Benz works, with production at Maschinenfabrik-Augsburg-Nuernberg (M.A.N.), Krupp and Nibelungenwerke beginning in April 1945. It strongly appears that production of the Ausf. F had not commenced at any of the plants by the cessation of hostilities, although the evidence to confirm this is less than clear.
By the later stages of the war the Heereswaffenamt (Army Weapons Office) were well aware of the benefits of conserving materials and equipment, and easing the logistical problems inherent in manufacturing, supplying and maintaining a wealth of different vehicle types. A gradual process of standardisation was begun. One part of this process was that the Panther II and Tiger II were to share as many components as possible. Furthermore, the E-series (Entwicklung, meaning development) of tanks and tank destroyers was intended to standardise German AFVs as much as possible. The E-50 and E-75, being considered as replacements for the Panther and Tiger II respectively, were to have been very similar indeed, differing primarily in armour thickness and the number of road wheels; the E-75 would likely have mounted a heavier main gun than the E-50's 8.8cm Kw.K. The Schmalturm would have been the basis for the E-50 turret design.
At least two examples of the Schmalturm were recovered for evaluation by the Allies at the Daimler-Benz plant in Berlin-Marienfelde. One was transported to the Aberdeen Proving Ground in Maryland, America, the other going to the Royal Armoured Corps' Bovington Camp, Dorset, England. The example brought to England is now at the Tank Museum in Bovington, but has unfortunately suffered from being used as a target on the Larkhill firing range, being "rescued" during the mid-1980s. The turret basket, half of the right side and almost all of the left turret side are missing. The front plate and roof sport large cracks. While being beyond restoration, it is currently being tidied up in the museum's workshop so that it can be put on public display at some time in the relatively near future. The specimen recovered to the Aberdeen Proving Ground seems to have vanished without trace. At the moment the only records of it appear to be previously published photographs.
It is a widely held opinion that the Panther was the "best" tank of the Second World War, and to suggest otherwise can bring about a vociferous response! The reliability problems of the Panther, particularly in the early stages of its operational history, are well known. Regardless of individual opinion of the Panther's sovereignty, had the Schmalturm turret entered production (on either the Ausf. F or Panther II) then a more potent vehicle would have unquestionably resulted; even more so had the 88mm or the semi-autoloading 75mm cannon projects reached fruition. Even so, given that by the late stages of the war Germany was rapidly running out of materials, manpower and production capacity, it has to be questionable whether the technical advantages the Germans designs held over their opponents' would have made any significant difference. To give a perspective, the production figures of the more heavily armed and armoured Russian IS-2 had already reached two-thirds that of the Panther and was still increasing while German production was declining.
Schmalturm Armour Protection:
Turret roof 40mm @ 90°
Turret front 120mm @ 20°
Turret side 60mm @ 25°
Turret rear 60mm @ 25°
This article is intended to provide an overview only of the turret's development. The development of the chassis of the Panther Ausf. F, Panther II and E-50 has been briefly mentioned where it is of relevance to this topic. A wealth of information has already been written about the subject, and for a more detailed insight the first two books mentioned below are recommended. A particular mention should go to Thomas Jentz for his painstaking research, which has clarified many misapprehensions regarding the subject.
Germany's Panther Tank. , Thomas L. Jentz, Schiffer 1995
Panther and Its Variants. , Walter J. Spielberger. Schiffer 1993
Armoured Firepower. , Peter Gudgin. , Sutton 1997.
BAOR Technical Intelligence Report No. 27. , 27 August 1945.
The Other Panthers. , Vasko Barbic. , Article, Army and Navy Modelworld, April 1984.
David Fletcher, Curator, Tank Museum Bovington.
Red Army Handbook 1939-1945. , Steven J. Zaloga & Leland S. Ness. , Sutton 1998.
some Landships (Rattes)