This turret had been associated with the planned Panther II. For a while it was thought to have been designed solely for it. The new turret was actually developed independently and was considered as an upgrade for both the ageing Panzer IV which was in its Ausf. J model at the time, and the Ausf. F and G models of the fearsome Panther.
The Schmalturm project (meaning “Narrow Turret”) was originally developed by the armaments manufacturer Rheinmetall. After their attempt failed somewhat, the project moved to Daimler-Benz in February 1944. This is where the name “Schmalturm” was born.
It followed specific design requirements, these were:
– Elimination of the shot trap under the mantlet
– An increase of protection while keeping the weight of the turret as low as possible.
– A decrease in the overall size of the turret, while still leaving the crew room to work efficiently.
– Addition of a stereoscopic rangefinder (The lack of this was one of the reasons Rheinmetall’s wasn’t approved).
– The replacement of the MG34 machine gun with the newer MG42. Make it easy for conversion into a command tank version (Befehlpanzerausführung).
– Make it compatible with possible IR device installation.
– It should Keep the standard Panther turret ring diameter (1650mm).
– Finally, Make the whole thing easier, faster and cheaper to produce.
Daimler-Benz’s prototype of the Turret, off-tank. (Photo – Achtungpanzer.com)
The turret granted increased armor protection in the shape of a 150mm conical mantlet leading to the 120mm front plate. The turret sides were 80mm thick outwardly angled to increase the effective protection. Despite the increased armor and narrower shape of the turm, the internal volume of the structure remained the same.
The KwK 44/1 in a special mount used for firing tests. Source:- http://www.oocities.org/
The Schmalturm turret was designed to carry the deadly KwK 42 75mm L/70 tank gun. In order to accommodate this powerful cannon, modifications had to be made to the recoil system. Czech designers managed to create a new version of the canon with a shorter recoil system. This was designated it KwK 44/1. This allowed gun to have +20/-8 elevation/depression. The usual muzzle break was also removed from the barrel.
The cannon was more than capable of dealing with Soviet and Allied vehicles of the time. It could penetrate 89mm of armor at 2000m, 112mm at 1000m and 124mm at 500m.
Panzers Considered for Upgrades
Panther Ausf. G and F
These models of Panther were the test beds of the Schmalturm turret, and were to be the first to receive the upgrade, should it have ever gone ahead. The tank needed little in the way of modification to accommodate the new turret.
Panther Ausf. F mit 8.8cm
A diagram of the possible inclusion of the 88mm cannon, note just how little space is left in the turret. (Source – ftr-wot.blogspot.co.uk)
A further planned development of the turret, designed by Krupp in 1944, was the inclusion of the 88mm L/71 cannon, thus creating the Panther Ausf. F mit 8.8cm.
To mount this larger gun, the pivot point of the cannon was moved forward and protected by a bulbous housing, in front of which was the conical mantlet. This upgrade, however, would have necessitated the enlargement of the turret ring by 10cm.
Panzer IV mit Schmalturm
It is very unlikely that this mating would’ve been a success. The already overloaded Panzer IV Ausf. J chassis would have never been able to carry the added 7,5tons of the turm. The vehicle was already at its limit with 80mm frontal armour and 7,5cm L/48 main-gun, a weight which caused bending frontal springs and forced an enormous tension on the final drives. Also, the Ausf. J had no electrical turret traverse and used a simple mechanic turret traverse with a gearing for the gunner.
Early in September 1943 another concept was penned. Wa. Pref. 6 asked Krupp if it would be possible to squeeze the Panthers 7,5cm L/70 in the standard Panzer-IV turret. Krupp’s reply was as simple as “No”. Another order from April 12th 1944 demanded to equip a modernised Panzer-IV chassis with 7,5cm KwK-42 in a modernized turret, but this turret had only 50/30mm of armour and had a weight of 4,5tons.
The Panzer IV mit Schmalturm would’ve been the final and most powerful form of the Panzer IV model of tank, which at the time of the turret’s development was starting to be phased out.
Tank Encyclopedia’s own rendition of a Panther Ausf. G mounting the Schmalturm turret.
An early mockup of the turret on a standard Panther Ausf. F chassis. Note the muzzle break still on the gun. (Photo – Panzer Tracts)
The same early mock-up as above seen from the side. (Photo – Panzer Tracts)
An upgraded version of the turret with the added stereoscopic sights, mounted of a Panther Ausf. G chassis. (Photo – Panzer Tracts)
Bovington’s surviving Schmalturm, displaying the damage sustained in live-fire tests. (Photo – Chris Droesch)
A diagram of Rheinmetall’s schmalturm. Source:- www.oocities.org
Rheinmetall had been tasked with designing the Panther II turret. This new turret was named Panther 2 Turm mit schmale Blendenausführung, meaning turret with narrow mantlet. The cancellation of the Panther 2 project came in May 1943, but Rheinmetall continued their work, with their turret now destined for the original Panther.
Rheinmetall’s progress was sluggish, as 1 year later, they had not yet progressed beyond the drawing stages as evidenced by drawing H-Sk 88517 “Turm – Panther (schmale Blende)”.
New requirements were drawn up by that time for the next Panther version, the Ausführung F. An Entfernungsmesser was to be incorporated into the turret and the gunner’s sight was to be changed to a periscope in the roof. Rheinmetall’s design incorporated the Entfernungsmesser in the turret but this created a huge hump in the turret roof.
It appears this design, combined with the long time already used with no practical results, prompted Wa. Prüf. 6 to move responsibility for the new Schmalturm from Rheinmetall to Daimler Benz. It seems about nothing from the Rheinmetall Turm – Panther (schmale Blende) design was used by Daimler Benz for their Schmalturm design. By 20 August 1944, the first Versuchs-Schmalturm was mounted on a Panther Ausf. G chassis.
Not a single Panzer IV would ever feel the power of this new armament however, even though there were copious amounts Panzer IV hulls, no Schmalturm ever touched its turret ring.
A number of prototype turrets had been produced and tested on and off Panther Ausf. F and G, however, and was also tested on the Panther II prototype. None of these projects left the prototype phase however, and both the Pz. IV mit Schmalturm and Panther Ausf. G mit 8.8cm never progressed further than pencil lines on paper.
Two of the prototype turrets were retrieved after the war by the Allies. The Americans took one while the British took the other and used it for ballistic tests. The remains of this turret can be found in the Bovington Tank Museum.
Links & Resources
Panzer-IV und seine Varianten (Panzer Iv and its variants) Spielberger and Doyle
Panzer Tracts issue No.5-4, Panzerkampfwagen Panther II and Panther Ausfuehrung F
Panzer Tracts issue No.20-1, Paper Panzers
The Author would like to thank Marcus Hock and Herbert Ackermans for additional information.