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WW2 German prototypes

Demag D II ‘Liliput’

ww2 German half-tracks Nazi Germany (1934-36)
Unarmoured Half-Track – At Least 3 Completed

The D II series of experimental half-tracks arose from the German Army’s pursuit of motorization in the years preceding the outbreak of the Second World War. Following successful trials with prototype designs that utilized the half-track principle in the late 1920s, semi-tracked trucks and prime movers became an integral component of this overarching drive for greater strategic and tactical mobility. Capable of achieving high speeds on roads as well as traversing difficult cross-country terrain, these vehicles appeared to be an excellent means of motorizing the German Army (Reichsheer). Convinced by these many advantages, the Heeres Waffenamt (Army Ordnance Department) assigned one of their most talented engineers, Heinrich Ernst Kniepkamp, the task of overseeing the development of a range of different half-tracks to fulfill the various needs of the German Army.

Having already approved the development of several designs capable of hauling heavy loads of up to five tonnes or more, in 1934 the Heeres Waffenamt initiated work on a smaller design that would be more suitable for towing lighter infantry guns and anti-tank guns. In response to these requirements for the Kleinster geländegängiger Ketten-schlepper (smallest cross-country tracked towing vehicle), the Demag firm produced small numbers of three consecutive prototype half-tracks: the D II 1, the D II 2, and the D II 3.

Known by their diminutive appellation ‘Liliput’, these comparatively small half-tracks nevertheless employed a whole host of innovative technological features that would go on to find widespread use throughout the Second World War. However, despite numerous incremental improvements across the three permutations of the D II series, the final D II 3 design still required further refinement before it could be considered suitable for series production. As a result, the overall design of the D II 3 continued to be gradually revised between 1937 and 1938, until it evolved by way of the interim D 6 into the final D 7. Classified as the Sd.Kfz.10 1-tonne half-track by the Heer, over 10,000 of the D 7 half-tracks would be produced from 1938 until the end of the Second World War.

In light of the ubiquity of its descendants, the D II 3 was a significant stage in the development of German semi-tracked prime movers. Even though the early D II designs appear to be far removed from the future Sd.Kfz.10, the underpinnings of a reliable workhorse had been established by the time the D II 3 was produced in 1936. As such, these obscure machines (of which we know very little) represent an important chapter not only in the development of German prime movers but also in the German Army’s quest to fully motorize its forces; a goal that, contrary to Nazi propaganda, would never be achieved.

A D II 3 half-track demonstrating its off-road capabilities. This machine was intended to be a mobile lightweight towing vehicle, with the versatility to perform well on paved roads or rough terrain. Consequently, it was designed to use a torsion bar suspension on both the tracked section of the running gear and on the front road wheels. In order to determine the best features, the D II series were tested with two types of tracks, as well as pneumatic tires or solid rubber tires on the front wheels. Seen here with all-steel tracks and solid tires, this D II 3 is unique in that it appears to have had a camouflage scheme applied to the hull. Consisting of two colors separated by stripes of a third darker color, this style of application does not conform to the usual Buntfarbenanstrich (a multi-colored scheme comprising three camouflage colors) that adorned many German military vehicles of the early 1930s.

Solving an Old Problem: The Motorisation of the German Army

Following Germany’s defeat at the end of the First World War in November 1918, the fledgling Weimar Republic inherited a strategic conundrum that had bedeviled generations of German military planners: how could the German armed forces defend Germany’s vast frontiers to both the east and the west with an army that was primarily reliant on railways for its mobility? Worse still for the German generals, the stipulations of the Treaty of Versailles compounded Germany’s vulnerability by placing size restrictions on the size of the military and banning the use of much of the latest military technology, including tanks. Confronted with this perennial German predicament and many hostile neighbors, the Reichsheer aimed to solve this problem by cultivating a highly mobile professional army that could rapidly respond to enemy incursions and form the nucleus of a resurrected German army capable of conducting its own offensive operations. In order to realize these strategic aspirations, the Reichsheer needed to enhance its tactical mobility. This, in turn, required one essential ingredient: the motorization of the German Army.

Correspondingly, significant emphasis was placed upon procuring motorized transportation for the Reichsheer, particularly in the form of tractors to tow artillery, in order to ensure that Germany’s limited military assets possessed the mobility to make a difference on the battlefield. These efforts culminated in the Kraftfahrüstungsprogramm (Motorisation Programme) formulated by the General Staff during 1927 and 1928. According to this initiative, the Reichsheer would specify its automotive requirements and provide technical specifications for designs that would be able to fulfill its needs. Whilst the 1920s saw many developments in this field, the Weimar Republic’s clandestine attempts to rearm in defiance of the Treaty of Versailles were accelerated with the accession of Adolf Hitler as German Chancellor in January 1933. Under the Nazi Party, which was vehemently opposed to what was perceived as the emasculating and unjust dictates of Versailles, plans to rebuild and motorize the Reichsheer were given greater priority and would eventually receive considerably more funds for research and development.

Among the many experiments in motorization undertaken by the Weimar Republic and continued by the Nazis was the development of three-quarter tracked vehicles (commonly known as half-tracks) for the purposes of carrying loads and, more importantly, towing artillery. Encouraged by earlier successes with these vehicles, Waffen Prüfwesen 6 (Wa Prüf 6), the sub-division of the German Army’s ordnance department responsible for the development of tanks and motor vehicles, initiated the creation of a light, medium, and heavy class of three-quarter tracked vehicles for the Reichsheer in 1932. At first, these vehicles were identified in accordance with their load-carrying capacity, but they were later reclassified to reflect towing weights of 5 tonnes, 8 tonnes, and 12 tonnes respectively. This reorientation originates from the conceptualization of these vehicles as prime-movers for the German Army’s various artillery pieces and trailers.

One of the products of this push for the motorization of the Reichsheer was the one-tonne three-quarter tracked vehicle. Although the initial requirements for three-quarter tracked vehicles prepared by Wa Prüf 6 in 1932 had not called for anything with less than 5 tonnes of towing capacity, there were plenty of anti-tank guns and infantry guns in development during the 1930s that would benefit from motorised towing, but which did not require a tractor with a 5-tonne towing capacity. Therefore, in order to provide prime movers for these indispensable constituents of German infantry formations, Wa Prüf 6 expanded the range of three-quarter tracked vehicles in 1934 to encompass a design with a one-tonne towing capacity. It was due to this imperative of motorization that the rather odd-looking Demag D II came into being.

The Demag D II 1 towing a 3.7 cm Pak anti-tank gun (left and an ammunition trailer (right). The trailer is most probably a Sd.Ah.32 used for transporting 3.7cm Pak, 7.5cm Le. IG, and 15cm s.IG 33 ammunition. Similar photographs exist of the Demag D II prototypes demonstrating their ability to tow 2cm Flak anti-aircraft guns. Although poor quality photographs (see Panzer Tracts 22-1 for better quality images), they show the unconventional appearance of the D II 1 and the rubber-padded track links associated with many of Kniepkamp’s designs. Due to the space taken up by the rear-mounted engine, the D II 1 was only capable of carrying four men. Sources: valka.cz & Forum.axishistory.com

The Dark Ages: The Genesis of the One-Tonne Half-Track

Whilst the overarching narrative recounting the mobilization of the Reichsheer is relatively well-known, the more intricate details pertaining to each particular vehicle are, by contrast, exceedingly scant. Nowhere is this more apparent than in the all-too-typical case of the one-tonne half-tracked vehicle, of which there are no surviving primary source records from either Demag or Wa Prüf 6 concerning its early development and production. Historians of the Medieval period may resent the ‘Dark Ages’ paradigm, but it is an apt term to describe the loss of information regarding the history of many interwar German military vehicles.

Consequently, the only comprehensive source available that outlines the early history of the one-tonne three-quarter tracked vehicle is a report compiled after the war in June 1946 by the British Army of the Rhine (BAOR). Entitled ‘German Semi-Tracked Vehicle Development from 1934 onwards’, this document provides a detailed overview of the history and the technical features of most of the German three-quarter tracked vehicles developed before and during the Second World War. However, the fact that the information in this report was primarily derived from post-war interviews with relevant personnel from the design firms and Wa Prüf 6, who did not have access to their records, means that it can contain significant errors and omissions. In the case of the one-tonne three-quarter tracked vehicle, the BAOR report contains only a brief synopsis of the production and technical features of the trial vehicles. Faced with this barren documentary record, there is little that can be said about the events leading up to the completion of the first Demag D II 1 sometime in 1934 or 1935.

Piecing together the evidence that is available, it is probable that the one-tonne half-track started development in 1934 as part of an effort to create a light prime mover that could advance at high speeds along paved roads and negotiate rugged terrain. The idea that the one-tonne three-quarter tracked vehicle was envisaged as a towing vehicle for light artillery, such as the leichtes Infanteriegeschütz 18 (le. IG 18) or the 3.7 cm Panzerabwehrkanone (3.7 cm Pak), is supported by a myriad of photographs showing trials vehicles hitched to these guns and their ammunition trailers, as well as the wartime use of their successors in this exact role.

Having established a need for this lightweight towing vehicle in 1934, Wa Prüf 6 contracted Demag AG, a crane manufacturing company based in Wetter an der Ruhr, to produce a series of trial vehicles (Versuchs-Fahrzeuge) incorporating their desired technical features and adhering to the prescribed specifications. Although Demag was a large industrial concern specializing in heavy equipment such as cranes and steam locomotives, this appears to have been their first project involving the development of half-tracked vehicles. Unfortunately, there is no information revealing why Demag was chosen to design these trials vehicles, or whether there were alternative concepts considered for this role. Whatever the wider story behind the early stages of the one-tonne half-track, between 1934 and 1936, Demag designed and produced a series of distinctive three-quarter tracked vehicles known as the D II, all of which employed several novel and unique technical features.

An excellent view showcasing the poorly optimized internal layout of the D II 1. Thanks to this overhead view, it is possible to appreciate the vast space consumed by the BMW 6-cylinder petrol engine. This design decision left little room for accommodating crew members and their various accouterments. In contrast to the previous photographs of the D II 1, this example has been equipped with the all-steel track links which do not have any rubber pads. Source: valka.cz

Micro Machines: The Development of the D II 1 and D II 2 ‘Liliput’

The first incarnations of the D II are immediately recognizable due to to their diminutive size and unconventional appearance. It is thanks to these characteristics that this series of machines received the peculiar moniker ‘Liliput’, an adjective (spelled ‘Lilliput’ in English) that denotes an object or person of extremely small size. Originating from Jonathan Swift’s famous eighteenth-century novel Gulliver’s Travels, in which Lilliput is an imaginary island inhabited by miniature 15 cm tall people, the term entered the European lexicon after this popular novel was translated into different languages. Whilst it may seem strange for a German military vehicle to be referred to by this esoteric label, the term ‘Liliput’ was sufficiently well-known in contemporary Europe that it became the name of one of the smallest semi-automatic handguns ever produced, the 4.25 mm Liliput Pistol, which was designed and manufactured by Waffenfabrik August Menz in Germany between 1920 and 1927. It is unknown how this term came to be attached to the Demag D II, but it appears to have been a contemporary name that aptly captures the strange appearance of these tiny machines.

Asides from its noteworthy name, the first variant of the Demag D II series developed between 1934 and 1935, the D II 1, also incorporated a number of unusual technological innovations. Whereas the other German semi-tracked vehicles mounted the automotive components onto a traditional chassis frame, the D II 1 encased all of these parts inside a unique lightweight hull. This novel approach to the construction helped to ensure that the machine would remain as light as possible, thus increasing its maneuverability and cross-country performance.

These performance characteristics were enhanced by Kniepkamp’s revolutionary torsion bar suspension, fitted to both the front axle as well as the tracked section. This worked in conjunction with the interleaved road wheels to provide the D II 1 with excellent mobility across challenging terrain, not to mention relatively fast speeds on paved roads. Although these features do not seem particularly remarkable in light of their widespread employment in later German designs of the Second World War, the Demag D II 1 was one of the first three-quarter tracked vehicles to use such an advanced suspension system successfully.

Kniepkamp’s penchant for cutting-edge technology and his preoccupation with speed, mobility, and weight are also evident in one of the types of track fitted to the D II 1. Alongside orthodox unlubricated pin cast steel track links intended to prioritize off-road traction, the D II 1 was also tested with lubricated needle-bearing track links, each of which carried a rubber pad. These track designs were viewed as a compromise between steel and rubber tracks, the former permitting higher speeds on road, with the latter being more suitable for off-road activity and more durable. By equipping German half-tracks with lubricated rubber padded tracks, Kniepkamp hoped to retain some of the beneficial performance and noise-dampening qualities of the rubber tracks, without sacrificing all of the resilience afforded by steel tracks. Although it appears to be the case that different track designs were still being evaluated at the time when the D II series was being tested, the lubricated needle-bearing rubber padded tracks had become a standard feature on all major German three-quarter tracked vehicles by the beginning of the Second World War.

Whereas the technical and automotive attributes of the Demag D II 1 fulfilled the brief for a light cross-country vehicle, other aspects of the design left something to be desired. Chief among these limitations of the D II 1, at least among those that are apparent without having access to any detailed testing reports, was the placement of the 1.479 litre 6-cylinder 28 hp BMW 315 engine. In another example of defying normal expectations, the engine of the D II 1 was not located in a separate compartment at the front, but was instead installed at the right rear of the hull, where it took up most of the space inside the rear compartment. As a result, there was room for only a driver and three additional men, with little space for extra stowage. For a vehicle designed to tow guns and carry their ammunition and crew complements, the lack of internal volume was a significant shortcoming that could only be rectified by a radical rearrangement of the internal layout of the hull.

One of the two known photographs of the Demag D II 2. Seen here crossing a trench, the D II 2 has been fitted with cast steel track links, which were known to provide better cross-country mobility than the rubber-padded alternatives. Curiously, there is also a triangular attachment of unknown purpose fitted to the front wheel’s hub. The many similarities between the D II 1 and the D II 2, such as the rear-mounted engine, the torsion bar suspension for the front wheels, and the hull construction, are readily apparent in this photograph. The civilian number plate ‘IY-02247’ seen on the front of the vehicle appears to have been used for all of the D II prototypes. Source: valka.cz

Sometime after the D II 1 was completed, the D II 2 was finished in 1935. In many respects, the D II 2 remained the same as its predecessor. It maintained the exact layout, engine, and suspension used in the D II 1, with the only major difference being the addition of an extra road wheel to the tracked suspension as well as a corresponding increase in track length. Other than the provision of a canvas cover to protect the driver from the elements, there were no more significant differences distinguishing the D II 2 from the earlier D II 1.

Consequently, by the end of 1935, Wa Prüf 6 was in possession of two lightweight compact towing vehicles capable of moving their light artillery. In the case of the D II 2, this translated into a vehicle capable of towing up to 600 kg, despite only weighing 2,560 kg fully laden. Moreover, it was able to attain a range of 250 km and a top speed of 50km/hr on roads, as well as scale a grade of 24 degrees unloaded or 12 degrees loaded. However, there were also significant shortcomings to these early designs which necessitated continued development by Demag.

An extremely rare photograph of the Demag D II 2 showing the extra fourth road wheel added to the suspension. Given the presence of both civilian and military observers, as well as the guide flags in the foreground, this D II 2 appears to be participating in some kind of training exercise or demonstration. It has been fitted with the lubricated rubber-padded tracks and a canvas cover over the cab to protect the driver from the elements. From this angle, it is also just possible to see the towing hitch and the rear-mounted exhaust muffler. Further in the background, there is a Sd.Ah.32 ammunition trailer, which is one of the loads that the Demag D II was designed to tow. Source: forum.axishistory.com

Towards the Sd.Kfz.10: The Demag D II 3

In 1936, the third and final incarnation of the D II, the D II 3, was assembled by Demag and delivered to Wa Prüf 6 for testing. In this guise, the D II came to more closely resemble the final shape of the mass-produced D 7. The original layout was discarded in favor of a more traditional setup, with the engine placed at the front in a separate compartment, whilst another road wheel was also appended to the suspension. Along with the conspicuous bulbous front fenders, these alterations to the D II 3 resulted in an appearance that bore a much closer resemblance to the later Sd.Kfz.10.

The D II 3 fitted with all-steel unlubricated tracks and pneumatic front tires. Compared to its predecessors in the D II series, the D II 3 had a more traditional layout with an engine at the front and the rear area reserved for passengers and cargo. Close examination of the photo shows a spare wheel attached to the rear, four rifles stowed behind the cab, and a couple of stowage boxes along the side. The radiator grille, large front fenders, and bug-eye headlamps give this machine a similar appearance to the later Sd.Kfz.10. However, the torsion bar suspension seen here fitted to the front wheels was a remnant of the earlier designs that would not be carried over to the D 6 and D 7. Source: valka.cz

However, the modifications to the D II 3 were not merely superficial aesthetic details. By replacing the BMW 315 engine with a larger 1.971 liter 6-cylinder BMW 319, the D II 3 was slightly more powerful than its predecessors. In addition to this, the relocation of the engine to the front of the vehicle improved cooling, thereby reducing the stress on the engine. Furthermore, the greater internal volume in the rear compartment meant that the D II 3 was able to transport 6 men in total, including the driver. For a vehicle intended to transport gun crews, this was a considerable upgrade to the design that increased its utility on the battlefield.

An overhead view of the Demag D II 3 highlighting the improved internal layout. By relocating the engine to the front of the vehicle, Demag created a rear area more conducive to carrying gun crews and their equipment. There was space for four passengers (as well as a driver and co-driver in the cab) and sufficient room to allow for stowage boxes to be attached along the sides. Source: valka.cz

The suspension also underwent several notable alterations. The solid road wheels of the D II were replaced by five road wheels of a new 6-holed variety. Coupled to a larger idler wheel that was mounted close to the ground, the extra track contact area provided by this refined suspension improved flotation on soft terrain, thus ameliorating the cross country mobility of this machine.

Another crucial evolution to the D II 3 design was the substitution of rollers in the place of teeth on the front-mounted drive sprocket. By using rollers, the friction between the track links and the sprocket was decreased. This reduction in resistance allowed the D II 3 to attain higher speeds and was to become a staple feature of later German three-quarter tracked designs.

In the same way as its forebears, the D II 3 was trialed with at least two different track designs, as well as two kinds of front wheels. In terms of tracks, this consisted of a familiar all-steel design alongside Kniepkamp’s lubricated rubber-padded tracks. These tracks could be combined with either pneumatic tires of a type similar to the D II 1 and D II 2, or a solid rubber variety. Unsurprisingly for an experimental vehicle like the D II 3, the photographic evidence is sparse and, due to the quality of surviving photos, difficult to interpret. However, photographs show that both types of tracks and front wheels were equipped on the D II 3, and seem to suggest that the different tire designs were tested in combination with both track variants.

An unusual photograph of a D II 3 in service with the Heer. This example has solid rubber front tires in place of the pneumatic versions used by the earlier D II prototypes and some D II 3s. Alongside these road wheels are all-steel tracks enveloping the distinctive six-holed road wheels. The flag-shaped object mounted next to the left side fender is a flag staff, a metal frame used to hold various pennants and flags that would help to identify the specific unit that the vehicle belonged to. Although these were a common feature on pre-war half-tracks, they were dropped from new production vehicles during the early stages of the Second World War. Source: forum.valka.cz

If the technical features of the D II are relatively well-documented by the BAOR report, production figures for these earlier vehicles are more opaque. According to the British, 38 D II 3 were completed by Demag. However, this claim is not confirmed by any surviving German records from the time and does not accord with the usual practice of producing trial vehicles in small series of one to five examples. This suggests that this statement in the BAOR report may be one of its many errors, but without the original German records, no definitive answer can be obtained. In either case, it is clear that in spite of the considerable improvements, the Demag D II 3 was an experimental vehicle that required further development in the eyes of Wa Prüf 6.

A D II 3 parked in front of two Panzerattrappen (dummy training tanks created on the basis of passenger cars). This particular specimen has solid front wheels fitted in combination with rubber-padded tracks. These tracks would have provided a faster, quieter ride on the paved areas in this courtyard compared to all-steel track links seen on other examples of the D II 3. The unfolded windshield shows two turn signals protruding from either side. These would later be relocated to a slightly lower position on the side of the hull on the D7. Source: valka.cz

Waste Not, Want Not: The D II 3 as a Testbed

Despite their shadowy existence in both the documentary and the photographic record, German prototype vehicles rarely enjoyed a quiet life. Rather than allow their experimental machines to languish in storage, many of the German trial vehicles ordered by the Heeres Waffenamt saw later use as testbeds for new concepts or technology. The Demag D II 3 was no such exception to this rule.

Even before the end of 1935, the Heeres Waffenamt had already presented a report outlining the tactical advantages of creating self-propelled 2 cm Flak guns on the basis of existing half-tracks. The report noted that due to the greater muzzle velocity and the superior penetration of the 2 cm Flak 30 anti-aircraft gun compared to other weapons of this caliber, it was not only an effective defense against air attacks but could also be employed to protect marching columns against surprise tank attacks. Taken by the merits of this idea, the D II 3 and D 6 experimental half-tracks were used to test a superstructure able to mount a 2 cm Flak 30 with 360 degrees of traverse, which would go on to be used on the mass-produced Sd.Kfz.10/4 anti-aircraft half-track.

Generally, such experiments mentioned in the documentation are devoid of photographic evidence, but every so often, stray photographs are published which illuminate these forgotten chapters of a particular vehicle’s career in service. In the case of the D II 3, there are at least two photographs confirming that at least one of the D II 3 experimental chassis fitted with solid rubber front tires and all-steel tracks was used to test this idea.

The D II 3 fitted with a trial superstructure for mounting the 2 cm Flak anti-aircraft gun. There are many similarities between this vehicle and the Sd.Kfz.10/4 produced in 1940. Chief among them are the loading ramps protruding from the front of the D II 3 and the small cable pulleys located just behind the driver’s cab. These would be used to load and unload the 2cm Flak gun from the rear of the halftrack, should it be desired to emplace the gun in a static position. Strong resemblances between this vehicle and the Sd.Kfz.10/4 can also be seen in the design of the folding sides, which have four bins attached to either side for carrying one magazine of 2 cm ammunition. Also, note that this D II 3 is using the solid front wheels rather than pneumatic tires and the all-steel tracks. Source: valka.cz

Close examination of these photographs reveals many similarities between the design of this trial superstructure and the standard style used on the Sd.Kfz.10/4, such as the four ready bins for one twenty-round Flak 30 magazine attached to the folding sides. Puzzlingly, the D II 3 testbed also has several features that were not fitted to Sd.Kfz.10/4 produced in 1939, but which did become standard in 1940. These include the loading ramps protruding from the front of the vehicle and the cable rollers just behind the driver, which were intended to allow the 2 cm Flak 30 to be dismounted from the half-track so that it could be emplaced in a concealed position on the ground.

Unfortunately, it is difficult to say any more about this experimental vehicle due to the lack of additional evidence. It is not even clear when this trial machine was modified in this manner, although it is probable, given its role as a testbed, that the conversion was completed between the production of the D II 3 in 1936 and the date at which the first orders for the Sd.Kfz.10/4 were issued in May 1939. Nonetheless, this example of reusing a prototype machine exemplifies the importance of the D II series in establishing the design parameters for many of the 1-tonne half-tracks that would see successful wartime service.

Another photograph of the D II 3 with the experimental superstructure for mounting a 2cm Flak gun. Examples of this superstructure were also fitted to Versuchs-Serie D 6 and 0-Serie D 6 half-tracks for testing. Source: Unknown

Stepping Stones: The D II in Retrospect

By the end of their development in 1936, the D II series of prototypes had established the foundations for a half-track design capable of meeting the specifications for a lightweight cross-country towing vehicle outlined by the Heeres Waffenamt in 1934. Although the D II 1 and D II 2 had many peculiar characteristics that were later dispensed with, they also pioneered several ingenious features that would be carried through to the mass-produced D 7, most notably the torsion bar suspension and the substitution of a hull construction in place of the conventional chassis frame. When the positive aspects of the early D II machines were amalgamated with numerous improvements introduced in the D II 3, the basic outline of the future Sd.Kfz.10 became fixed in shape.

Even so, the external similarities between the Sd.Kfz.10 and the final incarnation of the D II can be misleading. There would be multiple adjustments to almost every single facet of the existing design before its finalization as the D 7 in 1938, including changes to the engine, front axle, and road wheels. Nevertheless, In spite of these many modifications distancing the D 7 from the D II 3, these earlier vehicles still performed an important role in establishing the basic parameters and characteristics for their successors.

Consequently, the D II series must not be perceived as an evolutionary dead-end, but as a key step in the history of the development of the ubiquitous Sd.Kfz.10. Whilst none of the D II prototypes have survived to this day, their influence can still be appreciated through the mass-produced D 7, which is as prolific in present-day collections of German military vehicles as it was on the battlefields of the Second World War.

Soldiers posing with their solid rubber-tired D II 3. The opened bonnet provides a small glimpse into the engine bay, at the front of which is the radiator for cooling the BMW engine. Markings have been stenciled onto the side of the hull, but unfortunately it is not possible to discern their meaning. Usually, such markings were applied to trucks and half-tracks to remind crews of their weight, towing capacity, and other important specifications. The background does not furnish many clues as to where this photograph was taken, but the front of a Panzer I can be seen poking into the background. Source: valka.cz

Bibliographical Comment

The lack of surviving documentation concerning the history of the Demag D II series of vehicles means that the BAOR Report is still the primary source of information regarding these half-tracks. For those unable to access this report, Panzer Tracts 22-1 is an essential resource for further reading into this topic. As well as quoting directly from the BAOR report, this Panzer Tracts volume also highlights possible errors and provides several photographs of the D II that have not been published elsewhere. In addition to this, the coverage of the later D 6 and D 7 developments has revolutionized our understanding of the history of these vehicles. Older works of literature, such as those authored by Spielberger and Milsom, also summarise the history of the D II as presented in the BAOR report, but they should be used with caution when researching the rest of the Sd.Kfz.10 family, as they each contain errors and outdated information. Finally, a considerable number of photos of the D II that have not been published in printed books have surfaced on the internet, the majority of which have been published in this article.



Illustration of the Demag D II 1 half-track prototype with the rear-mounted engine and with the windshield up.
Illustration of the Demag D II 3 half-track prototype with the engine in the front.

Both illustrations by Alexe ‘Carpaticus’ Pavel, funded by our Patreon campaign.

Variant D II 1 D II 2 D II 3
Crew 1 + 3 1 + 3 1 + 5
Dimensions ? 3.4m (L) x 1.6m (W) x 1.7m (H) 4.4m (L) x 1.8m (W) x 1.7m (H)
Weight (laden) ? 2,560kg 3,400kg
Automotive Components 28 HP BMW 315 1.479 litre 6-cylinder petrol engine
ZF 4-speed transmission
28 HP BMW 315 1.479 litre 6-cylinder Petrol Engine
ZF 4-speed transmission
42 HP BMW 319 1.971 litre 6-cylinder petrol engine
ZF 4-speed transmission
Towing Capacity ? 600kg 600kg
Maximum Speed ? 50 km/hr ?
Range ? 250 km (on roads) ?
Gradient ? 24 degrees (without load)
12 degrees (with load)
?

Sources

Doyle, Hilary L., and Jentz, Thomas L., Panzer Tracts No.22-1 Leichter Zugkraftwagen 1 t (Sd.Kfz.10) Ausf.A und B and Variants: Development and Production from 1935 to 1945 (Maryland: Panzer Tracts, 2009).
Milsom, John, German Half-Tracked Vehicles of World War 2: Unarmoured Support Vehicles of the German Army 1933-45 (London: Arms and Armour Press, 1975).
Spielberger, Walter J., Die Halbkettenfahrzeuge des deutschen Heeres 1909-1945 (Stuttgart: Motorbuch Verlag, 1976). Translated into English as Halftrack Vehicles of the German Army 1909-1945 (Pennsylvania: Schiffer Publishing US, 2008).
Spielberger, Walter J., Die Motorisierung der deutschen Reichswehr 1920-1935 (Stuttgart: Motorbuch Verlag, 1979).Photograph of D II 2. Date of Access: 14 June 2018.
Photographs of the D II 3. Date of Access: 14 June 2018.


Categories
WW2 German prototypes

Tigerjäger Design B

Nazi Germany (1943)
Assault Gun – Design Only

The Jagdtiger (Hunting Tiger) is a highly recognizable vehicle consisting of a huge flat-sided casemate built on the hull of the Tiger II Heavy Tank. What is less well known is that the Jagdtiger as we know it (design started in early 1943), was not the vehicle originally requested and that, by tracking that design philosophy and evidence, it is possible to see a completely different Jagdtiger; one which was never built yet still offers a fuller picture of the evolution of German heavy armor in the Second World War.

Conception

In the spring of 1942, the Army General Staff was requesting a 12.8 cm gun mounted on a self-propelled chassis capable of supporting the infantry and of destroying unarmored as well as armored targets at distances up to 3,000 m. Armor and firepower were the priority, not speed and maneuverability.

By 2nd February 1943, this demand became an official request in the form of a letter sent from Wa Prüf 4 (the Army High Command design office for artillery) to Friedrich Krupp of Essen, setting out the requirement to mount a 12.8 cm Sturmkanone (Eng: Assault Gun abbreviated to ‘Stu.K’) on a modified Tiger H3. The ‘Tiger H3’ concerned was what we now know as the Tiger II, which was not named as such until March 1943 following the abandonment of the VK45.02(H), which was at the time known as Tiger II.

The requirements from Wa Prüf 4 for the modifications meant moving the engine forward on the chassis, with the gun being mounted in a casemate at the rear. This philosophy was felt to have the advantage of keeping the barrel overhang for the tank to a minimum and allowing for a better distribution of weight, although it was not without problems, as would soon become apparent.

The firm of Henschel und Sohn of Kassel would be responsible for the design of the hull modifications to fulfill this project and was contracted to produce designs. The gun desired was a 12.8 cm Stu.K, and the intention was to simply take the 12.8 cm Kw.K. L/55 gun unchanged, in its entirety, along with mounts, breech, brake, and recuperator from the Pz.Kpfw. Maus, although there was a strong emphasis placed by the High Command on the removal of the muzzle brake, as this allowed the use of Triebspiegel shells for heavy anti-armor work. The design, therefore, was not simply an assault gun, but also a tank-destroyer too, the difference between the two being blurred in this regard.

Further requirements set out in this letter were the use of as simple a design as possible with an elevation of -8 to +15 and 15 degrees of traverse. The sighting for the gun consisted of the Sfl.Z.F.5 and Rbl.F.36 telescopes to allow for both direct and also indirect fire.

Panzerjäger Panther design

By the start of 1943, the attempts to mount a 12.8 cm gun on a chassis were focused on using either the Panther or Tiger II as a basis. The Panther design to mount this 12.8 cm gun followed the design request closely. The engine, cooling, and ancillaries were moved to the front of the hull, behind the driver and radio operator, with the fighting compartment at the back.

Panzerjäger Panther mit 12.8 cm. Note: image has been cropped and cleaned. Source: Hoffschmidt and Tantum

The 12.8cm L/55 gun was mounted in the front of a well-sloped casemate with sloping sides, a flat roof, and a sloping rear, rather akin to the design of the back of the Ferdinand. Elevation limits for this gun were just +15 degrees to -6.5 degrees which did not meet the -8 degrees desired. Further, the rather small space of the casemate for the breech of this huge gun likely restricted the traverse to below the required 15 degrees each way.

The advantages of the design, such as the less complex and expensive Panther chassis compared to the Tiger II chassis, and the reduced length, just 8.5 m long from the muzzle to the rear, were offset by its deficiencies, such as the gun placement complicating maintenance of the engine and transmission. It is also possible that the armor which could be carried was not felt to be sufficient on the Panther chassis but, regardless of why the design was dropped, the attention was switched to the Tiger II chassis instead.

Enter the Tigerjäger

The Panzerjäger Panther design was dropped at some point, but Dr. Erwin Aders, the design lead at Henschel und Sohn, was working on two alternative designs for a Panzerjager based on the new Tiger II design. By March 1943, Aders was actively considering armor for the design up to 200 mm thick on the front and up to 100 mm on the sides, although this was subject to change in order to keep the weight to 70-tonnes (77.16 tons) or less. The goal was to provide a finished design by June 1943.

On 12th April 1943, Aders’ designs for Henschel were ready and the name being used at the time was Tigerjäger (Hunting Tiger). Designs plural, because Aders presented not one design but two: Tigerjäger Design A and Tigerjäger Design B.

Competing Designs

Design A had completely disregarded the requirement of the initial design brief to move the engine to the front of the hull. Instead, this design kept the engine at the back, with the transmission at the front as it was already arranged on the Tiger II. Despite this, the hull still had to be lengthened by 300 mm. Spielberger, Jentz, and Doyle (2007) describe the frontal armor of this design as being 150 mm at 40 degrees on the glacis and 200 mm thick on the 60-degree sloping part on the front of the casemate. However, the side armor had been reduced from the 100 mm desired in March to just 80 mm in order to keep the weight down. In other words, the frontal armor was now effectively double or more than the Tiger I but with the same side armor as the Tiger II.

Construction of a casemate with the armor desired and enough room for the breech of the huge 12.8 cm gun created a major problem and the height of Design A had to be reduced by 40 mm to allow it to fit inside the German rail gauge height limits for transportation. This had the effect of reducing gun depression from the -8 desired to -7 but, other than that, the design had met almost all of the requirements desired in the original letter from Wa Prüf 4 in February.

Design B, on the other hand, was significantly more problematic. In order to meet the requirements of Wa Prüf 4’s request to move the engine to the front, the hull roof had to be raised. Further, the cooling system of fans and radiators would not fit and would require a total redesign but even so, the engine was put in the middle of the hull. This, in turn, created additional problems with the transmission of power from the engine to the transmission at the front and to resolve that dilemma would mean designing new intermediate gearing. If that was not bad enough, Dr. Aders had not managed to design an effective system for exhaust from the engine and ventilation as the new arrangement had created so many difficulties for the design, and that was just the automotive problems.

Along with this total redesign of the Tiger II to accommodate this new automotive arrangement and the casemate at the back, the vehicle was too large for the rail gauge. Altering the design in order to meet this limitation would further reduce the movement of the gun which was already reduced by the height of the hull in front of the casemate. Assuming for a moment that the height could be amended in the same manner as Design A, reducing the -8 depression to just -7, then we can only surmise that the figure of -7 would be yet further reduced by this engine deck-height issue to -6 or less. Significant benefits of this gun mounting which should not be forgotten, however, were that it kept the center-of-gravity of the vehicle further back and meant there was very little overhang of the gun over the front of the hull.

One more problem to add to this litany of issues was maintenance. Not only would Design B require parts unique to it which were not compatible with the Tiger II, such as the gearing and cooling systems, but access to these parts was hard too. The 12.8 cm gun and mantlet would overhang the engine deck and, with limited traverse and elevation, there was no means to remove the engine or transmission without first removing the gun. This would also have to be done anyway for the Design A option but only for a change of the transmission and not for the engine. A short note here is that, at this time, the only engine being considered for the Tigerjäger was the same as that of the Tiger II, the Maybach HL 230 TRM producing 700 hp.

When Design A was amended with the casemate 200 mm further back due to a design change over the gun mounting, it resolved the centre-of-gravity issues and also reduced the gun overhang at the front. Design B, therefore, offered little in the way of advantages over Design A and a whole slew of major and unresolved problems. With an urgency to get this heavy 12.8 cm assault gun platform into service, there was only one logical choice and Design A, despite not being the engine-forward design requested, was selected instead. Design A went on to be the Jagdtiger and Design B was dropped.

The Duplicate

The first ‘Tigerjäger Design B’, as previously described, dates to the first half of April 1944 and the creative mind of Dr. Aders at Henschel und Sohn. Just to be confusing for historians, there is another Tigerjäger Design B. In fact, it is actually written as ‘Tiger-Jäger B’ and also emerges from Henschel just a month after the first Tigerjäger Design B. This means it is almost certainly from Dr. Aders as well, as he was the chief designer at Henschel.

Given the fact it was almost certainly proposed by the same designer responsible for Tigerjäger Design A and Tigerjäger Design B, from the same firm and only separated by a month, it would be easy to assume that there may be an error and that there was, in fact, only 1 Tigerjäger Design B. Here though there is a lucky break for the curious, as the plans for the May 1944 Tigerjäger Design B, unlike the April 1944 Tigerjäger Design B, actually survive.

Tiger-Jäger B with 12.8cm L/55. This is a different Tigerjäger Design dated 15th May 1943. Source: Hoffschmidt

Looking at the plans for the May Tigerjäger Design B and comparing it to the description known for the April design, it becomes very apparent that they are not the same vehicle which have been confused. The April vehicle was an engine-forward, rear casemate design with the 12.8cm gun over the engine with a small projection, whereas the May vehicle is the engine-rearward center-casemate design just like that known for Tigerjäger Design A from April, mounting the same gun but only over the front of the hull and projecting forwards.

The May Tigerjäger Design B initially looks like Design A, but there is one key visual difference that is easy to overlook; a cut-away portion on the top edge of the glacis. This cut-away reduced the point at which the gun would foul on the hull during depression.

The armor listed on the plan for the May Tigerjäger Design B also matches the armor described for the April Tigerjäger Design A, namely 200 mm on the front of the casemate, 150 mm on the glacis, and 80 mm on the sides. As these armor figures both pre- and post-date the April Tigerjäger Design B, it can be reasonably assumed even without the plans that the armor would be the same.

Resurrection: September 1943

Design B might have failed but the idea of sticking the 12.8 cm gun is a rear-casemate engine-forward design certainly had one last surprise. This time it was not from Henschel but from Krupp.

On 24th September 1943, Colonel Crohn (Wa Prüf 6) wrote to Krupp about improving the armament for the Tigerjäger, which was now the Henschel Design A type vehicle. There had been problems with the 12.8cm L/55 from Krupp which was, as yet, still unfinished. The gun suggested by Colonel Crohn was the 12.8cm L/70 version of the gun which used the same two-piece ammunition as the shorter gun but would deliver a higher muzzle velocity for armor-piercing rounds.

Krupp set to work and on 21st October replied that they had altered the design (the current Design-A type vehicle) to take the L/70 instead of the L/55. The gun could still fit in the same mounts as the L/55 gun but caused serious problems. The extremely long barrel now projected nearly 5 m beyond the front of the tank, bringing the center of gravity much further forwards, leaving a great strain on the front suspension.

The solution, in one way, was obvious – put the gun further back. In fact, mount the gun in a casemate at the back of the hull and, in doing so, move the engine forwards. This was then unsurprisingly exactly what Krupp suggested. At the same time, they outlined what effect the use of an L/70 would have on the primary design they suggested, and outlined this exact alternative, namely moving the engine forwards and the gun backward. This would reduce the overhang at the front to just 2 m or so and bring the center-of-gravity further back too. The drawbacks though, would be the same as before on the Design B and, on top of this, Krupp foresaw an increase in weight too on top of the weight of the heavier gun. Krupp said that it would consult with Henschel on the matter but, as Henschel had already considered this problem, it is no surprise that this idea died as quickly as it started.

By the end of October 1943 then it can be said that the rear-casemate engine-forward Tigerjäger was well and truly dead as an idea.

Clues

Because the designs were both rejected,k as both had so many faults and neither drawing has survived, it is perhaps no surprise that the descriptions provided, along with a knowledge of the development of the 12.8 cm Panzerjager and Tiger II programs, only allow for an approximation or surmised layout to be offered.

Looking at all of the other Panzerjägers following this engine-forward principle, such as the Panzerjäger IV mit 8.8 cm L/71, the Elefant/Ferdinand with the 8.8 cm L/71, and the Panzerjäger Panther with the 12.8 cm L/55, they all share the same core elements of sloping casemate sides, flat roof, and a rear which slopes both out from the floor to about the midpoint before sloping back to meet the casemate roof.

It is also worth considering that rear-mounted guns were actually installed on the Tiger II chassis, such as the 17 cm Selsfahrlafette 17/21, better known as the ‘Grille’ (Cricket). For that design, the engine was brought forward and the gun taken to the rear. A look at the engine position in the Grille, therefore, provides a view of what the front section of Design B might have looked like with the engine brought forwards. Why was it not a problem for the Grille when this layout was such a problem for the Tigerjäger? Simple: the Grille’s 17cm gun could be elevated far enough that access to the engine and transmission was relatively easy, as the gun did not need to be removed first.

Plan view of the 17cm Grille using the Tiger II chassis with the engine brought forwards. The vehicle is facing to the left and the front of the casemate for the gun on the Grille is outlined. This illustrates yet another problem with the engine-forward design – the isolation of the two crew at the front from the crew in the back. Source: Frohlich
Artist’s impression of the Tigerjäger Design B. Source: Author

Without seeing the original design, it is not possible to know for sure what Tigerjäger Design B looked like and the ‘invention’ of a tank, however reasonable it may look, is avoided by serious historians, which is why the artist’s impression shown here by the author is offered with the warning that it is exactly that, a rough impression of what it might have looked like based only on the little information available and from contemporary designs. Only if, and when, the original drawings are found can it be known for sure how close this impression is to reality.

Conclusion

The Tigerjäger Design B was literally a ‘paper panzer’ – it never left the drawing board. Designed by Henschel exactly as was actually demanded, it was simply surpassed by the alternative design (Design A), the design which went on to be the Jagdtiger. Using a rear casemate design with the engine forward would have allowed the use of the 12.8cm L/55 (April/May 1943) or even L/70 (September/October 1943) without the otherwise enormous overhang and without the excessive weight on the front suspension. Nonetheless, the design caused other problems relating to maintenance, the need for new component parts and really was not needed. There had been serious delays already in the Jagdtiger program at the time and 12.8cm L/55 production was behind schedule; switching to a longer gun would simply have slowed things down even more and the L/70 was simply not necessary to deal with its intended targets.

Krupp’s ideas for mounting the L/70 in the Design A never came about either and its ideas about moving the casemate to the rear were equally impractical given the problems of engine access. As it was, the Jagdtiger would follow a more conventional layout and the Design B of April 1943 was dropped. Together, the discussions over the Tigerjäger come together to provide a fuller picture of the small, but important steps in the evolutionary process for the Germans’ heavy Jagdtiger program.



Illustration of the Tigerjäger Design B produced by Mr. C. Ryan, funded by our Patreon Campaign

Tigerjäger Design B (April – March 1943)

Total weight, battle-ready est. 75 tonnes
Crew 6
Propulsion Maybach HL 230 TRM petrol producing 700hp
Armament 12.8cm Kw.K. L/55 plus hull mounted machine gun
Armor Up to 200 mm frontal, 80 mm sides and rear. 40-50 mm roof

Tigerjäger Design B (September-October 1943)

Total weight, battle-ready est. 70 – 75 tonnes
Crew 6
Propulsion Maybach HL 230 TRM petrol producing 700hp
Armament 12.8cm Kw.K. L/70 plus hull mounted machine gun
Armor Up to 200 mm frontal, 80 mm sides and rear. 40-50 mm roof

Sources

Spielberger, W., Doyle, H., Jentz, T. (2007). Heavy Jagdpanzer: Development, Production, Operations. Schiffer Military History, PA, USA
Hoffschmidt, E., Tantum, W. (1988). German Tank and Antitank. WE Inc., CT, USA


Categories
WW2 German prototypes

Pz.Kpfw. Panther With 8.8 cm Gun Design Proposals

 

Nazi Germany (1944-45)
Medium tank – Project only

By 1944, the fate of the Großdeutsches Reich (English: ´Greater German Reich´), more colloquially known as Nazi Germany, started becoming clearer and it was certainly not in the favor of the Germans. However, the German nation was not ready to surrender. As a result, the Panzerkampfwagen V Panther, one of the armored staples of the Wehrmacht at the time, continued to see development and upgrades until Germany’s eventual defeat in May of 1945.
While the 7.5cm Kw.K.42 L/70 main gun on the Pz.Kpfw. V Panther was a formidable tank gun capable of engaging any armored vehicle the Allies were able to field at the time, it was felt that the gun lacked enough future-proofing. In retrospect, these sentiments may not have been completely unjustified seeing as how vehicles developed by the Soviet Union near the end of the Second World War, like the T-54 and the IS-3, managed to be frontally resistant to the 8.8cm Kw.K.43 L/71 as mounted on the Panzerkampfwagen Tiger Ausf.B. Other vehicles, such as the United States’ Heavy Tank T32 and Heavy Tank T32E1, could also be theoretically frontally resistant to most of Germany’s anti-tank arsenal.

This IS-2 Mod.1944 was tested against the 8.8cm PaK.43 L/71 and 7.5cm Kw.K.42 L/70. The upper hull was impervious to the 7.5cm at any ranges while the 8.8cm could defeat it at 450 m, making it a great example as to the difference that an 8.8cm could have made in a real combat situation. Source: warspot.ru
During mid to late 1944, the firm of Daimler-Benz was in the midst of developing the Schmalturm (English: ‘narrow turret’), a replacement for the regular Rheinmetall-designed Panther turret. The Schmalturm was supposed to be used on the Panzerkampfwagen Panther Ausf.F. Considering that the Schmalturm was set to replace the original Rheinmetall turret and presumably Krupp thought that turret would be more accepting of a larger gun, Krupp designed an up-gunned version of the Schmalturm with a minimal amount of modifications. Krupp´s drawing Hln-130 (also referred to as Hln-B130), called ‘8.8cm L/71 I, Panther, schmal’ in at least one of the drawings, shows the Schmalturm mounting a modified version of the 8.8cm Kw.K.43 L/71 dating back to October 18, 1944.

Faded drawing of Hln-130 showing the internals of Krupp’s proposal from a top-down point of view with the turret facing left. (Source: Yuri Pasholok.)

Hln-130 modified to show major components of the turret. The red outline shows the armor structure, turret ring in orange, cupola in purple, bulbous turret extension in yellow, 8.8cm Kw.K.43 L/71 gun breech in brown, and 8,8cm round in green.
The gun was able to be accommodated by creating an armored bulbous extension at the front of the turret. The trunnions on the 8.8cm Kw.K.43 L/71´s gun carriage were moved 350 mm rearwards along the length of the gun, or the gun itself was moved 350mm forwards on the trunnions depending on how one wants to interpret it. The new gun mantlet was entirely different compared to the pot-shaped mantlet used on the regular Schmalturm. The installation of this new, larger gun compromised internal space and would mean that the loader would have a tough time loading rounds into the breech due to the limited amount of space between the gun breech and the rear of the turret. The round had to be loaded at an angle going upwards from the base of the turret, where there was enough room to squeeze in the round to the breech. One further modification was that the aperture for the main gun differed from the regular Schmalturm, although the apertures for the gunsight and machine gun were to remain identical.
Krupp´s Hln-E142 drawing, called ´Pz.Kpfw. “Panther” mit 8.8cm L/71 (Kw.K.43)´, dating back to November 17, 1944, shows the turret from drawing Hln-130 or the Schmalturm mounting the 8.8cm Kw.K.43 L/71 mounted onto a regular Panzerkampfwagen V Panther chassis. Here it is revealed that the gun has a depression angle of -8 and elevation angle of +15. The whole length of the vehicle with the turret and gun facing forward is 9,250 mm (9.25 m) with the length from the very front of the chassis to the end of the gun being 2,650 mm (2.65 m) and the vehicle (excluding gun) being 6,600 mm (6.60 m) long. On December 4, 1944, Wa Prüf 6, the department of the Waffenamt in charge of the development of armored and motorized vehicles, awarded Krupp a development contract.

Drawing Hln-E142 showing Krupp’s proposal for mounting an 8.8cm Kw.K.43 L/71 onto a Pz.Kpfw. V Panther chassis. Source: Yuri Pasholok
Krupp was curious about Wa Prüf 6’s opinions on some of the aspects of the proposal and whether further development was worthy of advancing forward. Krupp asked Wa Prüf 6 these three following questions, which are taken verbatim from Germany’s Panther Tank: The Quest for Combat Supremacy.

  • Is there sufficient space for the loader?
  • Is the shape of the armored cover in the turret front plate acceptable?
  • Is relocating the center of balance about 200 mm forward plus a weight increase of 900 kg bearable?

For the first question, Krupp proposed mounting a wooden model of the 8.8cm Kw.K.43 onto a “Panther turret” in order to test the loading of the main gun. For the third question, Krupp proposed a test turret with the load being off-center. Wa Prüf 6’s exact responses are not known.
For the sake of brevity, Schmalturm mounting the 8.8cm Kw.K.43 L/71 on a Panzerkampfwagen V Panther will be referred to as ‘Panther-Schmalturm-8.8cm’ although it is important to note that this is not an official name and used here solely for clarity.

Renditions of Krupp’s Panther-Schmalturm-8.8cm proposal. Source: Doyle and Jentz

Daimler-Benz Joins In

A meeting by the Entwicklungskommission Panzer (English: ‘Tank Development Commission’) was held on January 23, 1945, in which Colonel Holzäuer from Wa Prüf 6 reported that development of the Panther-Schmalturm-8.8cm project was to be completed by Daimler-Benz. In addition, a wooden model is said to have been completed. Earlier, on December 12, 1944, Daimler-Benz had displayed a wooden model of the vehicle, but it is not known if it was the same wooden model Colonel Holzäuer reported or an unknown previous iteration.
The turret ring of the Daimler-Benz Panther-Schmalturm-8.8cm was to be enlarged by 100 mm, making it 1,750 mm compared to the turret ring on the regular Rheinmetall-designed turret on the Panzerkampfwagen V Panther (Ausf.D to G), which was 1,650 mm. In doing so it gained a single tonne of weight. It also carried 56 rounds for the main gun.
On February 20, 1945, Krupp and Daimler-Benz representatives, Wa Prüf 6, and Wa Prüf 4 (a sister department to Wa Prüf 6 in charge of the development of artillery) held a meeting comparing both Daimler-Benz and Krupp’s Panther-Schmalturm-8.8cm designs. One large difference was the gun itself. Daimler-Benz used a ‘8.8cm Kw.K.’ with the recoil cylinders installed underneath the gun and the turret ring widened by 100 mm, while Krupp opted to use, for the most part, a regular 8.8cm Kw.K.43 L/71 with repositioned trunnions in a mostly unchanged Schmalturm turret as mentioned earlier. Wa Prüf 6 recognized that Krupp’s design was an expedient one meant to save time, however, their representatives did not much appreciate the idea.
In the end, it was proposed that Daimler-Benz and Krupp would work together on a project involving the 8.8cm Kw.K.43 L/71 with relocated trunnions and a larger turret ring with Daimler-Benz tackling the turret and Krupp the gun, unsurprisingly. This would have lead to the creation of a more complex project, but also combine the best elements of both designs and create additional space inside the turret.
On February 27, 1945, it was decided by Wa Prüf 6 that Daimler-Benz would continue development of the Panther-Schmalturm-8.8cm and was slated to produce a soft steel prototype of the turret to the specifications listed. Some of the specifications listed below reflect Krupp’s Panther-Schmalturm-8.8cm design which might indicate their involvement.

  • Needed to depress -8 degrees and elevate 15 degrees, which Krupp’s design was able to achieve.
  • The turret ring diameter was to be enlarged to 1,750 mm which was designed to give the loader more room to do his duties. Daimler-Benz’s previous design had already accomplished this.
  • The vehicle had to use only the 8.8cm Kw.K.43 L/71 as its main gun. The bore evacuation cylinder was to be placed in the middle of the recoil cylinders above the gun.
  • The trunnions were relocated and the muzzle brake was removed similar to Krupp’s Panther-Schmalturm-8.8cm.
  • Interestingly, the trunnions were to be located on the “forward edge” of the turret front plate, implying that it lacked any turret front extension like Krupp’s design.
  • The turret front was to have a “smooth armor plate” with the apertures being as small as possible but including an aperture for the main gun, presumably with the coaxial machine gun included. It is not clear if the turret was to be equipped with a telescopic gunsight or a coaxial machine gun
  • Mounting the S.Z.F.2 or S.Z.F.3 stabilized gunsight was to be considered.
  • The turret traverse gear and the cupola were to stay the same as on the regular Schmalturm.
  • The design was to use either a 1.32 m or 1.65 m stereoscopic rangefinder. It should be noted that the regular Schmalturm could already mount a 1.32 m stereoscopic rangefinder.
  • The turret was to feature ready racks which would make ammunition easily accessible.
  • Emphasis was placed on a low turret height.
  • Lastly, the rear turret plate was to be sloped instead of “upright” as it was on the first wooden model of the Daimler-Benz Panther-Schmalturm-8.8cm. The wooden model might be the one showed off on December 12, 1944, but this is just speculation.

Krupp’s Return and Wa Prüf 6’s Variant

Krupp appears to have returned to the project under the request of Colonel Crohn from Wa Prüf 6 on March 8, 1945. They were to design an “armor shell” of the Pz.Kpfw. Panther Ausf.F turret (otherwise known as a Schmalturm) mounting the 8.8cm Kw.K.43 L/71 by March 12, 1945. Speculatively, considering that they were given four days to design, it might be the case that they simply took their previous design, such as like Hln-130 or a similar iteration around the same time, and adapted it to the existing Schmalturm design of the time.
On March 14, 1945, during a discussion of further developing the Panzerkampfwagen V Panther in the Generalinspekteur der Panzertruppen, the Waffenamt is said to have done an excellent job designing the ‘8.8cm Kw.K. L/71’ onto a Panzerkampfwagen V Panther, with Wa Prüf 6 being thanked specifically. If the Waffenamt’s ‘8.8cm Panther’ was to be put into production, existing Panthers that received major overhauls would also be subject to mounting a turret with the 8.8cm. A ‘Versuchs-Panther’ or a prototype of the 8.8cm Panther was to be built out of soft steel and completed by early June. Mass production was to begin in the last quarter of 1945 if the “necessary support” was given.
This significantly improved vehicle with the new turret and increased firepower would weigh just one tonne more than the “current Panther”. Armor was to protect the rangefinder and it featured a stabilized gun sight “about the same as the Panther-Schmalturm”. Fifteen rounds were to be stored and be accessible in the turret and fifty to fifty-four more rounds were to be stored in the hull, meaning a total of 65 to 69 rounds could be carried.
Wa Prüf 6 was requested by the Generalinspekteur der Panzertruppen on March 14, 1945, to build a Versuchs-Panther mounting an 8.8cm Kw.K. L/71 based off the wooden model Daimler-Benz had shown off on December 12, 1944. The turret was to be made out of soft steel and the superstructure of the hull was to be modified in an unspecified way. Wa Prüf 6 was to complete the Versuchs-Panther quickly and display the vehicle on time.
Albert Speer, who was the Reich Minister of the Reichsministerium für Bewaffnung und Munition (English: ‘Reich Ministry of Armaments and Munitions’), requested on March 23, 1945, a display of a Panther armed with an 8.8cm Kw.K. gun, along with other weaponry, to be viewed by Adolf Hitler some time in mid-April. Hitler, however, was never able to see the vehicle as it was never built.
Daimler-Benz representatives were interrogated by the Allies after the Second World War had ended. They claimed that they had made plans to mount the 8.8cm Kw.K.43 L/71 onto a Schmalturm equipped with a stabilized gun sight with the project still being early in development. A wooden mockup of the project apparently existed up to June of 1945, three months after the German defeat, but after that it was lost to time.

Conclusion

The Panther-Schmalturm-8.8cm isn’t one homogenous project as it is sometimes depicted. It is a series of unrelated and related projects from various different firms and organizations. In the end, arming the Panzerkampfwagen V Panther with an 8.8cm L/71 in a Schmalturm became little more than a fantasy. The war was nearing its end when actual progress was made and such a turret would have made no difference to the outcome of the war. Krupp’s proposal though would have been the most feasible when compared to the design from Wa Prüf 6 and Daimler-Benz’, since it was simply a regular Schmalturm with the 8.8cm Kw.K.43 L/71 stuffed inside. The Panzerkampfwagen Panther Ausf.F was already placed into production and at least two mostly finished Schmalturms were made by the end of the war, one of which was captured and analyzed by the United States and the other captured and analyzed by the United Kingdom before ending up as a range target. However, there would have been issues with this design. Along with the bigger gun, the design was, in general, worse ergonomically for the crew and the cramped interior would have hampered the crews’ ability to carry out their tasks. There is no real surprise as to why Wa Prüf 6 was not fond of this design.
On the other hand, it is rather difficult to judge the Daimler-Benz or Wa Prüf 6 designs as very little is actually known. It appears, though, that the Daimler-Benz design would have required significant changes to an already existing design (Schmalturm) which would cause even further delays. In the case of Wa Prüf 6’s design, not only was the design of the turret changed, but existing Panthers would have to have their turret rings widened by 100 mm which would cause even more significant delays.
Despite the technical challenges of fitting an 8.8cm L/71 gun into a space smaller than that which had previously accommodated a 7.5cm gun, all designs managed to come up with workable solutions. Undoubtedly, had the final design for the compromise Schmalturm come to fruition, it would have made the new Panther a more powerful vehicle on the battlefield with a smaller silhouette, smaller profile, more firepower and improved protection, but at the expense of the crew ergonomics in the turret and their ability to carry out their tasks.

Sources

Jentz, T.L. 1995. Germany’s Panther Tank: The Quest for Combat Supremacy. 1st ed. Atglen, Pennsylvania: Schiffer Publishing Ltd.
Jentz, T.L. & Doyle, H.L. 2001. Panther Tracts No. 20-1: Paper Panzers.1st ed. Boyds, Maryland: Panzer Tracts

Specifications for Krupp’s 8.8cm Schmalturm turret

Crew 3 (commander, loader, and gunner)
Armament 8.8cm Kw.K.43 L/71
-8/+15 gun elevation
Armor Armor: Presumably identical to Schmalturm with the exception of the mantlet and bulbous turret extension
Turret front: 120 mm (20 degrees)
Turret sides and rear: 60 mm (25 degrees)
Roof: 40 mm (horizontally flat)
For information about abbreviations check the Lexical Index


Krupp’s proposal for mounting an 8.8cm Kw.K.43 L/71 onto a Pz.Kpfw. V Panther chassis according to drawing Hln-E142. Illustration by Andrei “Octo10” Kirushkin. Funded by our Patreon campaign.

Categories
WW2 German prototypes

3.7 cm Flakzwilling auf Panther Fahrgestell “341”

Nazi Germany (1943)
SPAAG – 1 mock-up built

As the Luftwaffe (German Air Force) lost control over the skies over Germany in the second half of the Second World War, it could no longer provide sufficient protection against Allied aircraft. Panzer divisions were especially affected by the lack of cover from fighter aircraft because they were always at the center of the most intense fighting.
The Germans already had copious amounts of half-tracked Self-Propelled Anti-Aircraft Guns (SPAAG) of different calibres and weights (Sd.Kfz.10/4, Sd.Kfz.6/2, Sd.Kfz.7/1, etc). As these vehicles had very limited or no armor, they were vulnerable to enemy fire either from ground or air. The crew needed better protection from small arms fire and artillery/mortar high explosive fragmentation shell shrapnel. A tank-based anti-aircraft vehicle (German: Flakpanzer) could solve this problem, as it would have sufficient armor to resist most ground attacks with the exception of larger caliber guns. They would also provide some protection against air attacks, but even tanks could be destroyed by air ground-attack fire.

Side view of the Flakpanzer 341. Source
Many designs based on different Panzer chassis and weapons were tested and built during the war. The most successful were the ones based on the Panzer IV chassis (Möbelwagen, Wirbelwind and Ostwind), which were built in some numbers but were too late to have a significant impact on the war. One of the major shortcomings of all German Flakpanzers was the lack of a fully enclosed fighting compartment. As all were open-topped (because of easier construction, easier exhaust of gun fumes and the need to produce them as fast as possible), the gun crews were exposed to air attacks.
By the end of the war, the Germans tried to solve this problem by designing and building new Flakpanzers with fully enclosed turrets. One of these was the Flakpanzer based on the Panther tank, best known today as the ‘Coelian’.

History

In May 1943, Oberleutnant Dipl.Ing von Glatter-Götz, responding to the orders of Inspectorate 6, initiated the development of a new series of Flakpanzers based on already existing chassis. The Panzer I and II were outdated or used for other purposes. The Panzer III tank chassis was used for the production of the StuG III and thus not available. The Panzer IV and the Panzer V Panther were considered next. The Panzer IV tank chassis was already in use for several German modifications, so it was decided to use it for the Flakpanzer program. The Panzer V Panther was considered in case even the Panzer IV chassis proved to be inadequate for the task.
The Germans formed a commission for the analysis of the effectiveness of enemy ground attack planes. The report (dated 31st June 1943) stated that, in the case of dive-bombing, the lowest point that the enemy plane reached was 1200 to 1500 m at an angle of 45-80°. Planes using larger caliber machine guns or cannons attacked at an altitude of around 150 to 300 m. The committee suggested that the best way to bring down enemy planes was using direct fire autocannons. To effectively fight the enemy planes, the future Flakpanzer would have to have a fully rotating turret with a high angle of fire and the caliber used should not be lower than 2 cm, with the more powerful 3.7 cm being preferred.
To give the crew the best protection possible and to meet any future Allied developments, the Panther-based Flakpanzer had to have a fully enclosed turret that could be armed with several different proposed weapon configurations. These included the 2 cm Flakvierling, 3.7 cm (either twin or triple configuration), 5.5 cm Flakzwilling and even an 88 mm caliber heavy flak gun. The first proposed design drawings (HSK 82827) were completed by Rheinmetall in late May 1943. The armament consisted of four 20 mm MG 151/20 mounted in a specially designed turret. The elevation of the four guns was -5° to +75°. This proposal was never implemented, mostly due to the weak armament by the standards of 1944.
On the 21st December 1943, a Panzerkommision was formed to examine the further development of a Flakpanzer based on the Panther tank chassis. It was decided that the main armament should consist of at least two 3.7 cm caliber anti-aircraft guns. This requirement was later revised to two 5.5 cm Gerät 58 guns. The development of this new weapon had begun in 1943, but due to its complicated design, problems developing the ammunition and the late start of the program, only 3 prototypes were completed by the war’s end.
For the construction of the new turret, Daimler-Benz was chosen. The new turret had to fulfill several set criteria like armor thickness and having an effective traversing mechanism. The armor protection of the turret was to be impressive, with 100 mm frontal armor and 40 mm on the sides. The turret was to be moved by using a hydraulic drive which was powered by the tank’s own engine. The new turret design was to be ready by the middle of 1944, but nothing came from this.

Rheinmetall’s proposed Flakpanzer turret armed with four 20 mm anti-aircraft guns. Source

The Rheinmetall-Borsig “341” design

Unfortunately, being more or less a project only, there is little known information about this Rheinmetall-Borsig design. What is known is that, by the end of 1943, Rheinmetall-Borsig (or its subsidiary, Vereingte Apparatebau AG, depending on the source) began working on its own design for the new Flakpanzer based on the Panther tank chassis. The first drawings of the new vehicle were completed by 23rd May, 1944. One mock-up turret was built and placed on a Panther D and presented to Wa Prüf 6 at Kummersdorf, possibly in early 1945. Due to many reasons, it never went into production and the whole 3.7 cm armed Flakpanzer based on the Panther tank chassis was cancelled in January 1945 in favour of the larger 5.5 cm weapons.

Only one mock-up with a wooden turret was ever built and presented to German army officials. It was never adopted for service, mostly due to the need to focus production on Panther tanks. Source

Name

Depending on the source, there are different designations for this vehicle armed with 3.7 cm anti-aircraft guns. These include Flakzwilling 3.7 cm auf Panzerkampfwagen Panther, 3.7 cm Flakzwilling auf Panther Fahrgestell “341” or, simply, Flakpanzer 341. The designation 341 stands for the two main 3.7 cm guns (Flak or Gerät 341). This article will use the Flakpanzer 341 designation for the sake of simplicity.
It is also best known today under the ‘Coelian’ name. Coelian is actually the third name of Oberleutnant Dipl.Ing von Glatter-Götz, who was greatly involved in the development of the German Flakpanzer program. It is important to note that the Coelian designation was never used by the Germans and was possibly added after the war, like many similar German armored vehicle designations.

Front view of the Flakpanzer 341. The simple flat face of the lower part of the front turret and the angled upper part can be seen. Source: Unknown


What-if illustration of how a Flakpanzer 341 prototype with the later turret design might have looked like. Illustrated by David Bocquelet.

Technical characteristics of the Flakpanzer 341

Due to a lack of information, the precise Flakpanzer 341 technical characteristics are not known in detail.
The Rheinmetall-Borsig Flakpanzer was meant to be built using a new turret designed by the company and mating it with a Panther tank chassis. While sources do not explicitly mention it, it is possible that the chassis used for the production would consist of damaged ones returning from the front for repairs or major overhauls (similar to the Wirbelwind and Sturmtiger) rather than using new ones. The armor of the Panther hull was 80 mm thick at the front and 40 mm on the side and rear. The overall Panther hull would most likely have had only some minor modifications in order to speed up production.
The lower front and side section of the turret had simple flat plates. The top armor was sloped, probably in order to increase protection against air attacks. The rear armor consisted of one large rounded plate. There were at least two hatches on the top and one on the turret rear. Additional ventilation ports would most likely have been added to avoid the accumulation of fumes from the guns. The turret armor thickness was 70 mm, the gun mantlet had 80 mm, while the sides and rear were 40 mm thick. This was less than the Daimler-Benz version with 100 mm of frontal armor. It is interesting to note that, on Hilary L. Doyle’s drawing from the book Panzer Tracts No.20-2 Paper Panzers (dated from May 1944), the turret has a much more angled front armor design. The built mock-up had flat front and side plates, probably as these were easier to build. The turret was to be operated by a hydraulic drive powered by the Panther’s own engine.
For the main armament, twin experimental 3.7 cm (L/77) Flak 341 guns were chosen. Some sources wrongly mention the 3.7 cm Flak 43 as the main armament. The 3.7 cm Flak 341 (3.7 cm Gerät 341) was an improved version of the same caliber anti-aircraft gun which was developed by Rheinmetall during 1944. The development process was too slow and only four prototypes were ever built. The Gerät 341 had a range of 4300 m, with a muzzle velocity of 1040 m per second and a rate of fire of 250 rounds per minute (or 400 to 500 depending on the source, but this was probably the maximum theoretical rate of fire of the two guns). The Flakpanzer 341 3.7 cm gun had a belt ammunition feed mechanism with some 1500 rounds of ammo for both guns. The ammunition would be stored beneath the turret, in the vehicle hull. The Flakpanzer 341 turret had a full 360° of traverse, and the gun could elevate between -5° and +90°. The total weight of the guns and the mount was around 470 kg. The secondary weapon would have been the radio operator’s ball-mounted MG 34 in the glacis plate, with one more possibly mounted on the turret roof.

The Flakpanzer 341 with the guns at high elevation. Source
The crew would consist of four to five crew members. While the sources do not specify the precise role of these crew members, we can assume that it would be more or less similar to other Flakpanzer vehicles. In the Panther hull, there were seats for the driver and radio operator / hull machine gun operator.
The two hatches on top of their positions were unchanged. The remaining crew members would be stationed in the new turret. One (or two) loaders would be positioned on either side of the guns. However, because these were belt-fed, their jobs were much easier than with the earlier magazine feed systems. The commander’s position was behind the gun, and he was also probably the gun operator.
The estimated combat weight was around 40 tonnes. The average weight of Panther tanks (depending on the model) was in the range of 44-45 tonnes. With its 700 hp strong Maybach engine, the Flakpanzer 341’s mobility would most likely have been better than that of the regular Panther tank.
The dimensions of the Flakpanzer 341 would also be similar to those of the regular Panther, with the same length of 6.87 m and width of 3.27 m. The height would be the only exception, at 2.8 m to the top of the turret.

The Daimler-Benz and Krupp Flakpanzer 44 design

During 1944, Daimler-Benz and Krupp were also working on a similar Panther-based Flakpanzer. Their turret design had 60 mm thick front armor. It was armed with two 3.7 cm Flak 44 anti-aircraft guns. This project is somewhat confusing for a few reasons. The existing drawings circulating online of the alleged Daimler-Benz and Krupp Flakpanzer 44 are actually of the Flakpanzer 341 according to Hilary L. Doyle. In addition, despite the best efforts of historians, no solid information about the existence of the above-mentioned Flak 44 anti-aircraft guns could be found. There were two different 3 cm Flak 44 projects, but they progressed very little. In addition, in some sources, the 3.7 cm Flakzwilling 43 is wrongly identified as the Flak 44. It is possible that this variation of the Flakpanzer 341 design was mistook after the war as a different project. Being developed during 1944/45, when Germany was in a state of chaos and due to the lack of documentation, the impression of another design having been developed could have formed easily. Of course, due to a lack of proper documentation, this is only an assumption at best.

This is the alleged drawing of the Flakpanzer 44. In fact, this is a Flakpanzer 341 with a modified turret. Source

Reasons for cancelling the project

While the idea of a Flakpanzer equipped with a fully enclosed turret, armed with two anti-aircraft guns, based on the Panther was certainly tempting, there were many reasons why this project would not have been very successful. A fully protected turret offered the crew much needed protection from ground and air fire but it also led to a number of issues that had to be resolved. These included potential problems with ammunition feed loading and removing the used shell cases at 90° angles. Due to the low quality of the German propellant in the late part of the war, during firing, a lot of powder smoke and fumes would be produced which could be dangerous for the crew. A dedicated and efficient ventilation system had to be installed.
The turret controls had to be designed and built to quickly respond to crew commands. The main armament was also problematic. Instead of using already produced weapons, the Rheinmetall-Borsig designers decided to use the experimental 3.7 cm Flak 341. which was never adopted for service. In January 1945, Wa Prüf 6 submitted a report in which the 3.7 cm caliber was deemed as insufficient for an anti-aircraft vehicle of the size of the Flakpanzer 341.
Another problem was the acquisition of air targets. In an open-topped turret, this could be easily achieved by the crew by simple observation. In a fully enclosed turret, a specially designed periscope and sights had to be added.
While the fully protected turret offered many potential advantages, it was not easy to successfully design and build one. While, during the war, the Allies used vehicles with fully enclosed turrets, most anti-aircraft vehicles built after the war were open-topped (like the ZSU-57-2 or M42 Duster).
The most obvious reason why the Flakpanzer 341 was canceled was the high demand for tanks on all fronts across Europe. Thus, sparing any Panther tank chassis for roles other than tank and anti-tank versions was out of the question for the Germans.

Conclusion

Despite this, the development of the Flakpanzer 341 continued up to the war’s end. It never received a high priority and only wooden mock-ups were ever built. Even if the war had continued for some time, there was a small chance (if any) that the Panther-based Flakpanzers would have ever been put into production.

This vehicle would have similar dimensions to those of the ordinary Panther tank. Source

Sources

Duško Nešić, (2008), Naoružanje Drugog Svetsko Rata-Nemačka, Beograd
Peter Chamberlain and Hilary Doyle (1978) Encyclopedia of German Tanks of World War Two – Revised Edition, Arms and Armor press.
Walter J. Spielberger (1982). Gepard The History of German Anti-Aircraft tanks, Bernard & Graefe
Walter J. Spielberger (1993), Panther and its Variants, Schiffer Publishing.
Thomas L.J. and Hilary L. D. (2002) Panzer Tracts No.20-2 Paper Panzers, Panzer Tract
Petr C. and Terry G. (2005) Enzyklopadie Deutscher waffen 1939-1945 Handwaffen, Artilleries, Beutewaffen, Sonderwaffen, Motor buch Verlag.
Hilary D. and Tom J. (1997) Panther Variants 1942-1945, Osprey Military
Werner Oswald (2004). Kraftfahrzeuge und Panzer, der Reichswehr, Wehrmacht und Bundeswehr ab 1900, Motorbuch Verlag,

3.7 cm Flakzwilling auf Panther Fahrgestell “341” specifications

Dimensions 6.87 x 3.27 x 2.8 m
Total weight, battle ready Around 40 tons
Crew 4-5 (Gunner/commander, loaders, driver and radio operator)
Armament Two 3.7 cm Flak 341 guns with 360 degree traverse
Armor Hull front 80 mm, side and rear 40 mm,
Turret shield armor 80 mm, front armor front 70 mm side and rear 40 mm
For information about abbreviations check the Lexical Index
Categories
WW2 German prototypes

Maus

Nazi Germany (1942-45)
Superheavy tank – 141 ordered

It is impossible to consider the Maus and not be impressed by the machine as a feat of engineering. At 188 tonnes, it is the heaviest operational tank ever made by any nation at any time in any war and was made despite the shortages of raw materials, industrial capacity, and manpower at the time in Nazi Germany. Yet, despite the impressive achievement of making this rolling behemoth, the vehicle stands as a testimony to the total waste taking place in the German industry and the inefficiencies inherent in the way in which tank development was carried out. By the time the Maus was finished in 1945, it was a boondoggle. No amount of awe at the size, weight, firepower, or armor on this beast could disguise the incredible waste of resources it accounted for, nor could it make any difference to the outcome of the war. The Maus, as a weapon, was simply useless, yet the lessons learned from its development did find use in other programs and the very existence of such an enormous machine has inevitably drawn a significant amount of attention. Drawing both awe and fascination in equal measure, the Maus is a complex tank with a lengthy development.

Origins

Following the invasion of the Soviet Union on 22nd June 1941, the German army had quickly gained huge swathes of territory and destroyed, captured, or killed large quantities of Soviet troops, supplies and equipment. Yet, despite this success, the German army was unable to deliver a knock-out blow against the Soviets or to capture Moscow. By January 1942, with Moscow saved by an increasingly stubborn Soviet defense, it was clear that the conflict on the Eastern Front was going to be very long and very bloody. As Soviet tanks of increasing quality, armor and firepower started to reach the front lines through 1942, it was clear that in order for German forces to maintain an edge in tank combat, they would need a tank that was bigger, more heavily armored, and better armed than anything that had gone before. There was also the need for a heavy tank capable of assaulting heavily defended enemy positions and since nothing in the German arsenal in Spring 1942 was capable of meeting these requirements, long term plans were being put into place.
The origins of the Maus began around this time as, on 5th March 1942, a directive was issued to Fried Krupp A.G. of Essen for the development of a new heavy tank in the 100-tonne class to replace the previous concept of a 72-tonne tank, which originated as a project by Rheinmetall started in 1938. The goal was to have an operational trial vehicle for this 100-tonne vehicle in the shortest possible time and to be ready to show it off in the spring of 1943. Two weeks later, on 21st March, Dr. Ferdinand Porsche was given a separate and independent contract for exactly the same goal, a 100-tonne tank.
Thereafter, requirements for this 100-tonne tank started to fall into line, with demands for a heavy gun, and at least one machine gun. The hull machine gun could be eliminated as long as there was a separately controllable machine gun, as this would simplify the design and eliminate the hole in the front armor needed to accept a hull machine gun. By May 1942, however, the 100-tonne limit was being seen as too conservative and a 120-tonnes weight was permitted with priority placed on achieving the heaviest possible armor and firepower. Speed was not an important factor.
Initial drawings were completed on 4th June 1942 by Porsche’s designers at Zuffenhausen. The project was named ‘Sonderfahrzeug IV’ (special purpose vehicle), but identified as the Project Typ 205. Completed drawings from Porsche for this 120-tonne vehicle mounting a 15 cm gun were ready by 23rd June 1942 and approved by Hitler. As an indication to the heavy armor proposed, the hull floor alone was to be 100 mm thick, the same thickness as the front armor that would be used on the Tiger I. Hitler approved the design, selecting a 10.5 cm L/70 gun and discounting the idea for a secondary turret with a 7.5 cm gun, as the tank was to be supported by other tanks. The priorities for the design had changed. In May, these had the armor on top, followed by firepower and speed in this order, but, in June, this changed to firepower, followed by speed and armor.
A contract was then issued on 17th July 1942 to Krupp to design a turret for this new tank under the name ‘Pz.Kpfw. Mäuschen’ (Tank: Little Mouse). This new turret, weighing 57 tonnes, was to be incredibly heavily armored, with armour 250 mm thick at the front (not including a large cast gun mantlet), 200 mm thick on the sides and 80 mm thick on the roof, and was to mount two guns (a 15 cm Kw.K. L/31 and a 7.5 cm Kw.K. L/24). Design work then proceeded on taking this enormous turret and firepower and producing from them a conceptual vehicle that could fit within the normal limits of the German rail gauge.

The enormous size of the Maus turret is evidenced here in 1945 by these Allied soldiers examining captured unfinished turrets. Source: UK National Archives
From August through September, work at Porsche continued on creating what was inevitably going to be a box-shaped vehicle in order to fit within the tight limits of the rail gauge. Combined with the work of Krupp on the turrets, it must have been considered to show significant promise too as, at the end of September, the turret being designed by Krupp was selected to replace the earlier 10.5 cm gun turret on the Löwe program and thus, Krupp received the contract for this too.

October 1942 – a design revealed

Between conceptualization in March 1942 and October 1942, it had been fairly plain sailing for both Porsche and Krupp, despite some general disagreements within the German establishment over a preferred gun or guns for the tank. On 5th October, the new design was ready under the name Typ 205A and had options for either a 15 cm L/37 or for a 12.8 cm gun to work alongside the 7.5 cm Kw.K. L/24.
The dominant feature of what was little more than an enormous brick with pointed ends fore and aft was the enormous rectangular turret roughly half the length of the entire tank. The engine was mounted ahead of the centerline but delivered drive to the sprockets at the rear via an electrical drive. The entire vehicle was to be mounted on 12 pairs of double road wheels running along a 1 m-wide track, although a pair of 500 mm wide tracks were also considered. All told, this Typ 205A was going to weigh some 150 tonnes and, in keeping with common design practice, was still to retain a front-mounted machine gun in the hull on the right-hand side.
Power for this 150-tonne vehicle was to be provided by a single 44.5 liter, 12-cylinder Daimler-Benz water-cooled diesel delivering 1,000 hp at 2,400 rpm. This was connected to an electrical generator which, in turn, delivered the electrical current to a motor on each side at the back, each connected to a 918 mm diameter drive sprocket. This arrangement would allow the Typ 205A to reach a top speed of 20 km/h. An alternative engine, the 41.5 liter Typ 205/2 Porsche air-cooled diesel was also shown in October 1942 as an option. This was labeled as design ‘Typ 205B’ and could deliver 780 hp at 2,000 rpm.
A review of the Typ 205 A and Typ 205B Mäuschen took place in November 1942 by the Panzerkommission and resulted in Krupp and Porsche being ordered to make another design with the turret at the back.
The result was a 170-tonne proposal from Porsche for a rear-turreted version using the same Daimler-Benz 603 water-cooled petrol engine as before, but with the addition of a compressor. It was also to use the electrical transmission taken from the Panzerkampfwagen VI P (Tiger (P)). Consideration at this time was also given to the production of a Sturmgeschutz version of this rear-turreted Mäuschen, but this was rejected by Obert Thomale from Waffen Prüfungsamt 6 (Wa Prüf 6), the branch of the German ordnance department responsible for motorized vehicle design.

Typ 205 from December 1942/January 1943, showing the distinctive and very large rectangular Maus turret. Note the presence of a hull machine gun and the use of 5 bogey units with two pairs of road wheels each for the suspension, copied from the Tiger (P), but reduced from the 6 pairs drawn in October 1942. Source: Frohlich
When this work was presented to Hitler at the start of December 1942, he was supportive and ordered the production of a trial vehicle to be ready for operation in the summer of 1943, with a production of 5 vehicles each month thereafter assembled by Krupp. It is important to note that at this time the Porsche design was known as the ‘Maus’ and the Krupp design as the ‘Tiger-Maus’, but a dose of reality was also setting in.
From an original 100-tonnes to ‘maybe-if-necessary’ 120-tonnes, the weight had ballooned to 170-tonnes and so some weight needed to be stripped off. The easiest way to achieve this was to reduce the amount of steel in the vehicle, which meant reducing the level of protection it offered from 250 mm at the front and 200 mm on the sides to ‘just’ 225 mm and 180 mm on the front and sides respectively. With the Krupp designed ‘Tiger-Maus’ being judged to be the lesser of the two designs, it was terminated on 15th December 1942, with the Porsche design being selected, albeit with significant changes.
Further changes to the hull to accommodate the removal of the turret collar and allow for a tunnel for the driver and radio operator at the front to get to the turret without getting out were making the design process difficult. Even as these changes and other minor changes were discussed, a decision was made on production. Hitler met with Albert Speer (Armaments Minister) on 3rd January 1943 and ordered the Maus to be produced between three manufacturers. Porsche would design it, Krupp produce the armored segments, and Alkett would assemble these components into a functional tank. Hitler was adamant that the production of the tank should be able to begin by the end of that year and deliver the Mäuschen at a rate of 10 tanks per month.

January 1943

By January 1943, the preliminary ideas for the Mäuschen were out of the way and a decision was made that the proposal from Porsche, rather than the design from Krupp, was to be selected. Several key design decisions had been made regarding the layout of this tank. Firstly, there was to be no hull machine gun at all. It weakened the frontal armor and added another element of complexity to the design it simply did not need. Secondly, the idea of a connecting tunnel to link the driver and radio operator at the front to the rest of the crew was abandoned – these men would remain physically isolated from the others, but connected via intercom. One additional note here is that there was a 20 mm thick armored bulkhead behind the driving compartment, so that, in the unlikely event of that compartment being breached by a shell, the drive system would still be protected. Likewise, in the event of a fire in the engine bay, those men in the front would be protected. A small access hatch in this bulkhead was provided for maintenance purposes.
The massive turret was to go at the back with the engine in front of it, the electrical components underneath it and the motors behind it, while the armor specifications had been decided at the start of January 1943. With that, a full-sized wooden model was ordered to be shown to the Panzer-Kommission on 21st January.

The full-sized wooden model of the Maus as seen in May 1943, dwarfing the members of the military and industry representatives examining it along with Hitler (in the light-colored trench coat). The fitting at the back on the corners is the flamethrower system which was later dropped, saving 4.9 tonnes in weight. Note that the mockup still retains the large cupola. Source: Frohlich
Here, under the eagle-eye of representatives from Porsche, Alkett, Daimler-Benz, Skoda, Wa Prüf 6, the Army, and Krupp, various changes were suggested, including:

  • Larger crew hatches in the hull (Wannen-Ausstiegsluke)
  • A new lighter type of track (Laufkette)
  • A machine gun mounting next to the hull crew hatch (MG-Kuppel)
  • A 100 mm thick track guard (Kettenschutz)

In February 1943, the engine for the Maus became the focus of attention. A big tank, after all, required a powerful engine. Maybach had originally been offering Porsche a supercharged V-12 engine capable of delivering 1,000 hp, but that engine turned out to be a pipe dream and was dropped. As to Porsche’s preferred engine, the 36.5 liter Simmering-Graz-Pauker Sla 16 (X-16), this was not ready.
Instead, Porsche selected a vehicle-version of the new DB 603 aircraft engine, a 44.5-liter V-12 petrol engine known as the MB 503A. Fuel-injected, this engine could produce 1,200 bhp at 2,300 rpm, but could only deliver 1,080 hp of that power due to having to run engine accessories. The alternative engine available was the MB507C, a diesel version of the engine capable of producing up to 1,000 hp.
This engine was connected to a pair of Siemens direct current (DC) dynamos, each producing 400 kW at 2,800 rpm (total combined DC output was 720 kW, 240 volts, 3,000 amps) that were a reverse of the layout in the Ferdinand/Elefant. In that vehicle, the dynamo was (single dynamo in the Ferdinand and two dynamos in the Maus) in front of the engine; here, they were behind. This electric drive was selected primarily because it required less development time than a mechanical drive but also because it made deep fording much simpler. A key departure for the Maus from previous German designs was the placement of the final drives at the back of the tank.
One thing commonly forgotten or otherwise not paid attention to is engine maintenance. There were, obviously, removable hatches in the roof of the hull, but there was an additional hatch in the floor of the engine room, measuring 1,295 mm x 216 mm in the 50 mm armored floor rather than the 100 mm thick floor proposed back in June 1942.

One of the Maus hulls found by 21 Army Group at Meppen in May 1945. It shows the points of access to the engine, with a hatch in the 20 mm bulkhead to the driving compartment, the sections for the three large engine hatches, and the letterbox-shaped access in the hull floor. Note that the hull roof, where the turret is mounted, is made from four separate sections 60 mm thick, welded together. Source: UK National Archives

Engines for Mäuschen up to October 1942

Date ~June 1942 to October 1942 October 1942
Manufacturer Maybach Simmering Daimler-Benz Porsche
Name HL-230 P30* X-16 MB503A Type 205/2
Fuel Petrol Diesel Petrol Diesel
Cylinders V-12 16 V-12
Capacity 23 liter 36.5 liters 44.5 liters 41.5 liters
Cooling Type Water Air Water Air
Power Output 900 to 1,000 / 1,200 hp** 720 hp @ 2,000 rpm 1,000 hp @ 2,400 rpm to 1,200 hp @ 2,300 rpm+ 780 hp @ 2,000 rpm
Installed no no no no
Notes Not ready Not ready
Porsche’s preferred engine
Unable to supply engine, November 1942 Unable to supply engine, November 1942 – MB 509 selected instead

* When modified to run on ‘special fuel’ at an increased compression (Bosch fuel injection) and supercharged this was known as the HL 234
**In his 1945 interview, Von Heydekampf was clear that even supercharged, this engine could only achieve 900 hp – well short of the 1,000 to 1,200 planned
+ 1,080 hp available after driving engine accessories
MB = Mercedes-Benz

Engines for Mäuschen November 1942

Manufacturer Daimler-Benz Maybach Daimler-Benz
Name MB501 HL230 TRM P45 MB 507C
Fuel Diesel Petrol Diesel
Cylinders V-20 V-12 V-12
Capacity 134.4 litres 23.88 litres 42.3 litres
Cooling Type Water Water Water
Power Output 1,200 to 1,500 hp 700 hp @ 3,000 rpm 800 hp @ 2,000 rpm
850 hp @ 2,300 rpm
1,000 hp @ 2,400 rpm
1,200 hp @ ?
Installed no no Maus no.1
Notes 40-degree Offered as a temporary replacement if another suitable engine could not be found or supplied in time
MB507 selected as a short-term solution instead
Modified and downrated from Flugmotor DB603
MB503 converted to run on diesel

Intention to rationalize a common engine for Maus in line with R1 and R2 projects from Krupp
MB = Mercedes-Benz

Engines for Maus after November 1942

Date February 1944 December 1944
Manufacturer Daimler-Benz Daimler-Benz
Name MB 509 MB 517*
Fuel Petrol
(Min. 77 Octane)
Diesel
Cylinders V-12 V-12
Capacity 44.5 liters 44.5 liters
Cooling Type Air Water
Power Output 1,080 hp @ 2,300 rpm** 1,200 hp @ 2,500 rpm
Installed Maus no.2 Maus no.2
Notes Modified (and downrated) from Flugmotor DB603A
Required installation upside down, requiring an additional gear train
At 2,300 rpm the engine absorbs 78 hp for fans and 5 hp for gearing
(total efficiency loss 7.5 %)
Modified motor-boat engine (installed upright)

* MB 517 engine converted from running on petrol to diesel
** A British Report of 1945 states that the MB 509 could deliver 1,540 bhp for 5 minutes at 2,500 rpm and 1,375 bhp continuously at 2,300 rpm using 87 octane fuel and that 74 octane fuel reduces engine power by 200 hp. The 1,375 hp @ 2,300 rpm figure is repeated in German documents from November 1942 detailing Maus development.
MB = Mercedes-Benz
DB = Daimler-Benz


MB 507 engine. Source: Frohlich
All of these changes had swollen the weight of the Maus by about 10 tonnes, mainly as a result of a 3% thickness tolerance on the armor plate and the addition of a Flammenwerfer Anlage (flamethrower system). This 10-tonne burden was further increased by additional ammunition stowage demanded by Hitler in May and a Gasschützanlage (gas protection system) in June.

Armor

The goal of the entire project was to create a heavy tank all but immune to enemy fire. The Krupp turret design from 17th July 1942 had armor 250 mm thick at the front, with a large cast steel mantlet in front of that. The side armor was to be 200 mm thick and it was to have a roof 80 mm thick. By the start of December 1942, the need to shed some weight had brought the suggested turret armor down from 250 mm on the front and 200 mm on the sides to 225 mm on the front and 180 mm on the sides, and, by the end of the month, it was reduced yet further. By the end of December 1942, therefore, the hull (Wanne) armor for the Mäuschen Typ 205 was also reduced, down to 200 mm on the front. The sides were to be the same thickness as would be used on the Tiger II, with 80 mm on the inner hull sides except that on this vehicle they would have an additional 100 mm outer skirt layer over the top. The rear was to be 150 mm thick with the roof of the hull 100 mm thick at the front and 50 mm thick at the back, although British measurements in 1945 of a scrap hull say that the space was for a plate 60 mm thick. The hull floor had been reduced from 100 mm across the full length to ‘just’ 100 mm under the front of the hull and 50 mm at the back.
In January 1943, the design from Porsche had won out over the design from Krupp and the armor, the source of a lot of debate and redesign, had been determined. A full-size wooden model of the ‘Maus’ was ordered, as it was now being known, which combined the Porsche Typ 205 hull with the Krupp Maus Turm.

Notes:
* figure based on calculated value suggested by Porsche’s 10% reduction
** Jentz/Doyle claim the July 1942 turret weighed 57 tonnes but also that Porsche’s plan to reduce the weight was to take it from 47 down to 43 tonnes (a 10% reduction) – this suggests a 10-tonne weight loss between July and November 1942 otherwise unaccounted for.
+ Estimated value
++ A confusing note from 10th April 1943 states that the original plan for the Maus was to use 80 mm side walls doubled over the upper sides to 160 mm with a weight of 150 tonnes, suggesting a different ‘Typ 205’ armor scheme was considered

The armor was to remain effectively unchanged from the acceptance in 1943, as any major changes would affect the wheelbase of the tank. In January 1943 though, it was proposed to make the side walls in one piece by ‘simply’ using one 180 mm thick plate and milling out 80 mm of the thickness for the bottom half. This would have the advantage of improving protection, as the armor would be all in one piece, but Krupp, the manufacturer of the armored hulls, had a different idea. It wanted 60 mm of the armor to be milled out to provide plate 120 mm thick over the wheels instead, but this could not be achieved without affecting both the wheelbase and the inner face of the armor, which was supposed to be made from softer steel than the exterior armor. Krupp however, did not give up, as the plan to make the sides in one piece and milling out what would be 4.5 tonnes of steel from each side plate was not an attractive one from a production point of view, as it was laborious, difficult, and wasteful of steel. Instead, Krupp proposed making it in two pieces, one 80 mm thick for the hull side and an outer layer 100 mm thick bolted to it. A further suggestion was to abandon the solid side plate altogether and to use a pair of plates. The idea was to not attach them together to be a homogenous panel of steel but to space them 30 to 40 mm apart on bolts. This, however, would involve a redesign of the tank, and the first Krupp alternative proposal also had to be rejected. Making the armor from two separate plates was complex due to the need to ensure they could fit and would reduce the protection from enemy fire due to the weakness of the bolts which might be used.
These ideas for changing how the side armor was to be made could not be executed at the time and still keep the production schedule for the Maus on track, but were not abandoned. They, along with another ‘spaced armor plan’ where the 100 mm and 80 mm plates were held just 10 mm apart (instead of 30 to 40 mm), and a plan for the entire side to just be a single 180 mm thick panel, were to be subjected to firing trials.
These potential improvements were confirmed in April 1943, when Porsche announced that it had improved the suspension system for the Maus so that it no longer relied upon a mounting on the inner face of the outer armor skirt. So simple was this solution that the lower section of the side armor could be made thinner (just 60 mm) and simply welded to the upper section. This was approved as a change for Wanne #7 onwards from the total of 120 tanks to be produced. This order was increased to 135 in May 1943.

Maus side armor proposals January to April 1943
(not to scale)

Scheme Image* Upper Side Lower Side Inner Hull Note
A
Milled armor
January 1943
180 mm 100 mm 60 mm Original scheme for Maus hull # 1
B
Krupp’s suggestion (Reduced Milling)
January 1943
180 mm 120 mm 60 mm Not possible as it interfered with the wheelbase
REJECTED
C
Double plates
March 1943
100 mm + 80 mm 100 mm 60 mm Complex to machine plates to fit exactly and difficult to secure together
REJECTED
D1
Spaced armor scheme
March 1943
100 mm + 30 mm (air) + 80 mm 100 mm 60 mm Would increase width beyond rail gauge limits and/or involve redesigning the interior
REJECTED
D2
Spaced armor scheme
March 1943
100 mm + 40 mm (air) + 80 mm 100 mm 60 mm Would increase width beyond rail gauge limits and/or involve redesigning the interior
REJECTED
E
Spaced armor scheme
March 1943
100 mm + 10 mm (air) + 80 mm 100 mm 60 – 80 mm Outer 100 mm plate and inner 80 mm plate spaced 10 mm apart but not bolted together to ease machining burden
REJECTED
F
Single piece – no milling
March 1943
180 mm 180 mm 60 mm Single piece of armor for the side with no milling – required new means of supporting the wheels
REJECTED
G
New suspension scheme
April 1943
180 mm 60 mm 120 mm With new suspension not connected to the outer armor, the lower plate could now be welded to the upper plate – reinforced inner hull
ACCEPTED
Arrangement selected for Maus hull #7 onwards

Note:
* Source – Author
Plate thickness manufacturing tolerance is +3 to +5%

So, the first six Maus hulls were planned to be made with a single 180 mm thick side plate which was milled down to 100 mm thick in the lower part but, after that, production would be greatly simplified by virtue of the improved suspension design. The side armor would still be 180 mm over the upper sides but the lower part could simply be welded on as the suspension was now connected only to the inner hull of the tank rather than spread to the side skirt. This is a good lesson in how a small design change in one component can deliver a significant improvement in manufacturing.
In February 1943, the armor for the Maus was, once more, under discussion. This meeting, held on the 4th, was not about methods of construction or proposed thicknesses required but on the material itself. In order to make sure the armor was as good as possible, it was suggested that instead of using the current standard type of armor plate, they should switch to using naval armor plating (marine platten) which had been made available and was considered to be of better quality than the standard-type plate. There was, however, a problem with the plates – not the weight or material, but the size. In order to be used, these giant slabs of steel would have to be rolled down to 2 m x 2.3 m and 200 mm thick.

Turret

Krupp met with representatives of Wa Prüf 6 in the middle of January 1943 to discuss the turret for the tank. Known as the ‘Maus Turm 12.8 cm’, the gun to be used was, unsurprisingly, a 12.8 cm piece. Back in April 1942, the 12.8 cm gun considered was an L/50, with additional thought given to using a longer gun of either 60 or 70 calibers. That was reiterated later with thought given to using a 61 caliber-long gun firing shaped charge ammunition or types of sabotted projectiles. In January 1943, the 12.8 cm selected by Wa Prüf 6 was an L/55 gun as it, combined with the new ammunition, would provide the performance required. Therefore, modifications would need to be made to Krupp’s turret design in order to accommodate this longer gun. Even so, there was the option of switching out that gun with a 15 cm L/38, and both were to be partnered with a 7.5 cm gun too.
January to February 1943 was a time of flux for the turret design. The idea of mounting a flame projector in the turret had been dropped but in its place were ideas for a 2 cm Flak anti-aircraft gun in the front as well as possibly a new type of range-finder (EM – Entfernungsmesser).

2 cm Flak MG151/20 anti-aircraft mounting as designed for the front of the Maus-Turm February 1943. Source: Frohlich
Between March and July 1943, four types of range-finders were considered: horizontal, vertical, T-shaped, and V-type. The 1.73 m horizontal type was impossible to use, as the position of the guns prevented it from being installed. A 1.0 m vertical-type range finder would have to be mocked-up in wood on the mockup Maus turret to assess whether or not the loader (or gunner) could even use it. The T-shaped range-finder was experimental and required a new housing measuring 80 cm x 20 cm on the turret roof which would allow the gunner to range and fire on his own but would also restrict the commander’s visibility and would be less accurate at long range. The final type, the V-type range finder, was in common use already but was discounted as it was required (after July 1943) to be protected by armor and operable when the tank was buttoned down in combat.

Welded Maus turret and behind it a completed Maus hull. Note the supporting pins used in the construction of the turret are still sticking out of the front left of the turret and have not yet been ground off. Source: Milsom

Close-up of the interlocking plate with supporting system – this photo shows the edge of the glacis after the explosion inside has blown off the side armor and broken the weld.
Adding to this growth in armament was a growth in protection, as the commander’s cupola (Kommandantenkuppel) was significantly uparmored to match the rest of the turret and the crew hatch (Einsteigklappe) was increased to 60 mm thick. With Wa Prüf 6 insisting on a small petrol/electric generator being added as well, the weight and complexity had increased although, as a plus-point, the vision ports (Ausblichluken) and empty cartridge ejection ports planned in the side of the turret (which would mean boring through the armor) were abandoned. The vision ports would be replaced with new periscopes (Schwenkspiegel) in the turret-roof and the spent casings could be tossed out of the ammunition hatch (Munitionsluke).

“The turret is a really massive structure being particularly high in relation to its width and length and in relation to the hull”
British examination report 1945

Even with dropping those ports, however, the weight of the Maus Turm (Turm Typ 205 ‘Maus’) had, by February 1943, crept over the strict 50-tonne limit set by Dr. Porsche in order to keep the total vehicle mass to no more than 180-tonnes. Changes followed through April 1943 with the addition of ports for machine-pistols in the side walls (Machine-Pistol-Luke) on a ball-mount (Kugelblende).
After the full-sized wooden mockup was shown to Hitler in May 1943, Porsche became very concerned about the shape of the front of the turret, as the inwards curve could lead to shells ricocheting into the roof of the hull. Porsche suggested that this could be obviated by inverting the lower curve to make it curve outwards rather than inwards. That change might add some additional room within what was becoming an increasingly cramped turret. So cramped that, when in May 1943 it was decided between Dr. Porsche and the Waffenamt to add a machine gun into the front of the turret, Krupp had to inform them that there was not enough room.
This was not the only design change proposed by Porsche that was making the life of Krupp difficult, as he [Dr. Porsche] had already been asked a couple of weeks earlier to stop modifying the turret or making new openings in the base (in that case for access to the crawl space) as they were weakening the structure of the tank. Even so, it should be borne in mind that the turret basket of the Maus Turm remained 55 mm thick and the floor plate was 93 mm thick.

Underside of the three Maus turrets found by Allied forces on the Meppen range in 1945 showing the heavily protected inner turret basket, 55 mm thick, and the 93 mm thick turret floor. Source: UK National Archives
Other problems would remain, however, such as the commander who had to turn to his left to avoid being hit by the recoil from the 7.5 cm gun and could not sit down when the vehicle was moving or in combat without being hit by the breech of the 12.8 cm gun or recoil guard for the 7.5 cm gun. Even standing, the commander had a problem as he was in the way of the loader when loading the 7.5 cm gun, so some shuffling around was needed to operate that gun in combat. Some shuffling of the turret-crew positions was implemented in July 1943, with the right-side loader moved to the back of the turret, where he would sit just inside the bustle. Combined with the removal of the ammunition loading assist system (Munitionstransportanlage), space could be freed up within the turret, reducing some complexities associated with this loading system, as well as allowing the loader to freely operate the smoke grenade launchers (Nebelwurf Gerät). The commander would be moved over to the position occupied by the loader and this simple change got him out of the way of the breech of the 7.5 cm gun as well as allowed him to operate the range finder. The gunner could also be moved, as his legs were in an awkward position. Moving him back to the position occupied by the left-side loader removed this problem and allowed him to not only operate the turret rotation mechanisms but also the machine gun in front of the turret. That loader was simply moved to the rear of the turret with the other loader.
This crew-shuffling was simply a result of too much crammed into the turret, which although massive on the outside, was significantly smaller on the inside, as the majority of the space was occupied by the breeches of the guns and their associated ammunition. Yet, despite these difficulties, there seemingly was no discussion of the obvious solution – remove the 7.5 cm gun.
At the same time as Porsche was suggesting the front curve being inverted, he also had the idea of adding a 3.7 cm anti-aircraft gun in an anti-aircraft turret (fliegerabwehr Kuppel) on top of the primary turret, capable of 360 degree traverse seemingly in contradiction to the fact that the turret was already at or just over the 50-tonne limit Porsche had personally imposed that February. Despite the difficulties with the turret design and ignoring Dr. Porsche’s concerns over the front curve and his less than stellar idea for an AA gun turret on top of the primary turret, a mockup was ready by July 1943.

The finished Krupp Maus-turm provides a good view of not only the enormous size of the turret and its massive cast mantlet around the primary gun, but also the interlocking armour and supporting rods at the armor joint on the rear. The hole in the side is the machine pistol ball-mount (MP-kugelblende) and in the rear is the loading port with machine pistol port (Munitionsluke mit MP-stopfen). Source: Frohlich (left) and Jentz and Doyle (right)

Primary Maus turret armor/design changes June 1942 to January/February 1943

Project Mäuschen
Name Krupp Maus Turm Krupp Maus Turm Krupp Maus Turm for Typ 205 Turm Type 205 ‘Maus’ 12.8 cm
Date ~1942 July 1942 November 1942 January – February 1943
Mass (tonnes) u/k 57 43** 49.5 / 51*
Front 250 mm required
(232-241.5 mm actual)
250 mm + mantlet 225 mm
Side 200 mm required
(204.4 – 205.4 mm actual)
200 mm 180 mm
Rear 200 mm required
(205.5 – 205.8 mm actual)
200 mm 200 mm
Roof 90 mm required
(90.8 – 91.5 mm actual)
80 mm 72 mm
Hatches 50 mm + 50 mm + 60 mm
Notes Tolerances for plates as follows:
Front: -3.4% to -7.2%
Sides: +1.75 to +2.9%
Rear: +1.75% to +2.15%
2 cm Flak added, improved cupola armor

Notes:
* 49.5 tonnes in January 1943, given as 51 tonnes in February, exceeding the 50-tonne limit imposed by Dr. Porsche that month
** Jentz/Doyle claim the July 1942 turret was 57 tonnes but also that Porsche’s plan to reduce the weight was to take it from 47 down to 43 tonnes (a 10% reduction) – this suggests a 10-tonne weight loss between July and November 1942 otherwise unaccounted for.

Primary Maus turret armor/design changes after February 1943

Project Mäuschen Maus
Name Maus Turm
(Porsche suggestion)
Maus Turm Type 205 with Maus Turm
Date May 1943 October 1943 December 1942

January 1943
Front 220 / 205 mm*** 225 mm
Side 200 mm
Rear 200 mm
Roof 60 mm
Notes Reshaping of the front to avoid the lower curve on the front
Addition of 3.7 cm AA turret
Curved front Curved front

Notes:
+ Estimated value
*** The 220 mm thick plate used for the turret front was only 205 mm thick after being bent into shape, although a post-war US intelligence report erroneously reported the thickness as 240 mm.

Armor Testing

As development and discussions over the fabrication of the armor for the hull were taking place with the newly designed suspension in January 1943, the work on the turret had also progressed. Krupp, the armor manufacturer for the turret and hull, was issued a contract for a single blank turret and two hulls for firing trials. These two hulls were not only testing the resistance of the plates to attack but also the strength of the welds joining what was to be the thickest armor ever mounted on a tank at that time. The standard method of fastening heavy plates together involved cutting interlocking joints in them and then welding over those joints. Other methods included simple welding of one plate to another and the supplementing of welded seams with a bolted joint-piece which could then be over-welded, as was done on the side hulls of the Tiger I. For the Maus, however, boring holes for a bolted support plate was not practical and the joining of the armor plates had to rely on welds supported by pins instead.
Hull number one (Model 1) was to have the interlocking parts of the armor plating cut by means of being milled out, whereas the second hull for firing trials (Model 2) was to have these sections cut out by means of a flame-torch. Cutting by means of the torch was faster and easier than milling out large pieces of heavy armor plate, but was considered to produce an inferior product than milling due to the accuracy of the surface a milled-cut would produce. A decision on which method was to be used would not be made until after the firing trials had been completed at Hillersleben in June 1943. Regardless of which method of cutting was to be used, the interlocking sections were to be supported by the use of 100 mm diameter connecting pins (Verbindung Bolzen) between these plates. The joint and pins would then be welded together, with the pins providing additional strength to the joint. These pins were important to the construction of the hull to support the welds, but were an additional burden on construction as they had to be bored out and were also considered to marginally weaken the overall armor protection where they were used. Their use was essential to the hull fabrication process but to reduce any effect on weakening the armor, they were reduced after June 1943 to just 80 mm in diameter.

Diagrammatic representation of the use of the verbindung bolzen (connecting pins) to add strength to the joint between two armor plates. Left to right: Plates cut and shaped, put together and holes bored, supporting pins (pink) fitted, and the edges are all-welded over. Source: Author

Production

Even before a finished design was ready or approved, Hitler, in November 1942, ordered that 5 Mäuschen were to be built and a timetable set by Wa Prüf 4 to achieve this. Turret and hull drawings were to be ready and approved by March 1943 and then 5 vehicles built within just 6-7 months- an ambitious and unrealistic schedule, as this also called for trials by 5th May 1943. The Heereswaffenamt (Army Ordnance Department) arranged for Colonel Haenel to help ensure timetables for the Maus were adhered to by going from firm to firm to press them to meet production requirements and, if necessary, assess severe penalties for missing deadlines.
Krupp received a contract in December 1942 for a complete prototype Maus turret (Versuschsturm) followed a month later by a contract for a hull. An agreement between Krupp and Porsche in the middle of January 1943 stated that assembly was to take place at the Alkett works by September 1943. Several firms were actually involved in the production of the Maus:

Primary firms connected with Maus production and development

Company Responsibility
Porsche Design and overall construction/development
Krupp Hull and turret fabrication
Daimler-Benz Engine development
Siemens-Schuckert Electrical apparatus
Škoda Suspension, tracks, and gearing
Alkett (Altmärkische Kettenfabrik) Assembly
Alkett Design and specification of tracks

The initial drawings for the turret and hull which were due in March were actually ready on 21st January 1943 and the production of 120 vehicles was ordered on 10th February.

Maus track link (top), track pin (bottom) and removable ice cleats (center) weighed 29 kg and measured 1,100 mm wide, 263 mm long, and 127 mm thick when complete. Each side of the Maus used 160 individual plates (4.64 tonnes per side). Seen here on the outside of the link (left) and the inside (right). Source: Frohlich and UK National Archives respectively
Production of the first Maus hulls had started very quickly after the design was authorized and, for this reason, it was too late to make the change to the improved side armor scheme for the first vehicles. By the end of May 1943 though, a problem had been identified. The tolerances on the armor plates of 3% meant that those 180 mm thick side panels could actually be up to 185.4 mm thick each, meaning an additional 11 mm or so in potential width. As the original design was exactly 3,700 mm wide, the maximum limit for the German rail gauge, any additional width created a huge problem as the tank would be ‘out of gauge’. As a result of the first four hulls already having been welded together that month, they were allowed to be finished as long as the width was kept to 3,715 mm, as even this ‘out of gauge’ width was just about manageable.
This width problem had to be addressed and, in order to guarantee that the maximum width would not be exceeded, after hull number 5 the outer 180 mm armor was to be milled down even more than before. An extra 10 mm was to be shaved off the outside, effectively doubling the amount of machining that was needed on those plates, as well as reducing the armor to 170 mm thick (upper) and 90 mm (lower). This was to be a temporary solution to the problem, rectified from hull number 14 onwards, where the plates were to be rolled 170 mm thick to begin with. The fact that in May they could only implement this change for hull 14 onwards strongly suggests that at least 13 hulls were already in preparation by 26th May 1943 when the order was delivered, with the first 4 nearly finished hulls undergoing assembly. Thus, before even the first vehicle was finished, there would effectively be 3 slightly differently made Maus – the consequences of not producing prototypes.
Exactly a month after this debacle was uncovered, in an effort to reduce the time required for welding, Porsche requested Krupp to mill the side plates of hulls 3 and 4 to match those scheduled for 5 to 13.

Maus Side Armor/Width and Manufacturing Differences

Hull (Wanne) Number Side Armor Maximum Width
1 180 mm (upper), 100 mm (lower) plus 3% allowable manufacturing tolerance
(185 mm / 103 mm max. thickness respectively)
Left side (upper) 191 mm, Right side (upper) 186 mm**
3,717 mm
2-4* 180 mm (upper), 100 mm (lower) plus 3% allowable manufacturing tolerance
(185 mm / 103 mm max. thickness respectively)
3,700
to
3,715 mm
3-4 180 mm (upper), 100 mm (lower) milled down to 170 mm (upper) and 90 mm (lower) 3,700 mm
5-13 180 mm (upper), 100 mm (lower) milled down to 170 mm (upper) and 90 mm (lower) 3,700 mm
14+ 170 mm (upper), 90 mm (lower) plus 3% manufacturing tolerance
(175 mm / 93 mm max. thickness respectively)
3,680
to
3,690 mm

Note:
* The order of May 1943 to keep hulls 1-4 ‘out-of-gauge’ was changed in June 1943 with hulls numbers 3 and 4 ordered to also be milled down to 170 mm like hulls 5 to 13.
** Hull number one was 11 mm out of tolerance on the left-hand side, and 6 mm out of tolerance on the right-hand side when it was assembled in July 1943

Further changes to the hulls were far less drastic than milling off 10 mm from each side. Through the summer of 1943, amendments to the hull were dominated by the boring of towing holes.
The only firm in all of Germany with a machine capable of milling these enormous plates was at Krupp’s factory and any damage to that machine would, therefore, cripple fabrication. Ensuring a system whereby the side armor needed no milling meant that production was not reliant upon a single machine. This was achieved by a reduction of side armor to allow for manufacturing tolerances to still stay within the rail gauge and the change to a type of suspension not dependent upon the side skirts to support it.
The production schedule was a tight one as well, with an order in May 1943 for the initial 120 tanks increased to 135, with the first two vehicles expected to be ready for November that year. Production of hulls, therefore, was supposed to be 5 the following month (December 1943) then 8 in January 1944 with production becoming streamlined and up to full speed with 10 per month from February 1944 onwards. The 120 production target, therefore, would deliver the last Maus hull (assuming things stayed on schedule) in January 1945 and the 135th Maus by April 1945. Turret production was expected to keep pace with the hulls, albeit to trail them by one month, with the 135th turret to be delivered in May 1945. The Waffenamt, however, had issued contracts for production of 141 Maus (6 experimental hulls and 135 serial production vehicles) by June 1943 and production of the main sections of armor had already begun when Generaloberst Guderian (General Inspekteur der Panzertruppen) overruled this order and reduced the order to just 5 in order for them to be tested under real combat situations before a full order was placed.
In the back and forth around production, the Panzerkommission changed this reduced order from a total of 5 to just 5 per month instead on 1st July. Eleven days later, the six experimental chassis already in hand were given official production serial numbers 351451 to 351456 (6 vehicles) with serial numbers assigned to production vehicles from 351457 to 351591 (135 vehicles).
When, less than a month later, Krupp’s plant in Essen was bombed by the Allies, the concerns about the single milling machine were proven to be justified. Production ground to a halt with a delay of a month to clear the rubble away, leaving 30 Maus in various stages of production. A previous bombing raid in March 1943 had not affected hull production but had caused an estimated 2-month delay in turrets as the wooden mockup had been burned. Thus, the first trial turret was not going to be available until the middle of November, a month behind schedule, and now two months behind the scheduled delivery of the first hull.

Maus Hull (Wanne) Production

Hull (Wanne) Group Hull (Wanne) Number Serial Number Status as of 4th August 1943
1 – 4* 1 351451 Hull welding finished 7th July 1943
Delivery delay for 4 weeks
2 351452 In Wagen Werkstatt (workshop) Delivery delay for 3 days until when rail lines are restored
3 – 4 351453 – 351454 In Wagen Werkstatt (workshop)
5 – 13 5 – 6 351455 – 351456 At Panzerbau (construction shop) – awaiting crane repair before they can be delivered for welding
7 351457 At Panzerbau (construction shop) – awaiting crane repair before they can be delivered for welding
8 – 9 351458 – 351459 Armor panels cut and at Panzerbau
10 351460 Most armor plates delivered by Panzerplatte Walzwerk (armor fabricators)
11 – 13 351461 – 351463 Most armor plates rolled but buried under rubble
14 + 14 – 30 351464 – 351481 Most armor plates rolled but buried under rubble
31 + 31 – 141 351181 – 351591 No work

Note:
* The order of May 1943 to keep hulls 1-4 ‘out-of-gauge’ was changed in June 1943 with hulls numbers 3 and 4 ordered to also be milled down to 170 mm like hulls 5 to 13.
Green highlight indicates Versuchs (experimental) series, Blue highlight indicates serial production

With production delays caused by bombing, Krupp, seemingly without any warning, received orders on 27th October 1943 that, instead of 120 vehicles, just 1 Maus was to be completed instead. All of the unused armor plates were ordered to be transferred to the Sturmgeschütz program at Harkort-Eicken instead, excluding those already prepared for use in Maus construction.
More bad news for Krupp followed, with an order to cancel further development of the tank and cancellation of orders for series production of the turrets and hulls. On 5th November, another order clarified the situation, changing the initial batch of 6 prototype turrets to just one. A week later the contract for 6 prototype hulls was changed to just 2.
With work canceled, there seemed little point in finishing hull number 1, which still needed some machining work done but was otherwise finished. It was sent from Krupp to Alkett on 26th September 1943, where it was fitted with the internal components and drive train. This was completed on 22nd December and then ordered to be shipped to the testing grounds at Böblingen on 10th January 1944. When it left for Böblingen the next day via railway, the vehicle was able to move under its own power and load itself, but work on the hull was otherwise incomplete inside. The journey to Böblingen took 3 days.
The second Maus hull arrived at Alkett on 8th January, but work stopped by the middle of the month with a focus on Sturmgeschütz assembly instead. After about a fortnight of lying idle, it was decided to ship the partially assembled hull (fitted with just suspension and mechanical brakes) to Böblingen to finish the work.

Maus hull number 2 on its 27 m railcar, 10th March 1944. Source: Jentz and Doyle
The single turret which had been ordered to be completed did not fare much better. It was not finished until the middle of April 1944, several months behind schedule – no doubt as a result of being a low priority project as serial production had been canceled.

Engineer Karl Gensburger from Alkett takes the Maus for a preliminary test drive around the factory, December 1943. Source: Ludvigsen
It was then inspected by Wa Prüf 6, which made several changes to the design to rectify some minor deficiencies, but neither Krupp nor Alkett were going to implement them at their primary factories. The Maus project was all but over and this single turret was to be sent directly to Böblingen instead, where technicians from Krupp could finish work on it. Arriving at Böblingen on 3rd May 1944, Turret number 1 was finally mounted on Hull number 2 during the night of 7th to 8th June 1944.

Maus hull number 2 mated with turret number 1 at Böblingen, June 1944. Note the towing eyes which have been added and that there are two additional shell deflectors on the hull roof. Hull number 1 did not have these deflectors. Source: Frohlich


Maus Typ 205/2 hull mounting the number 1 turret during tests. Note the Polish TKS tankette next to it, giving a sense of the size of this super heavy tank. Illustration by David Bocquelet

Suspension

The most critical element in a tank edging up towards 200 tonnes was how it was to be carried. Somewhat impressively, the designers of the various Mäeuschen never seem to have considered the ‘easy’ solution of adopting plain rollers, as was adopted on the much lighter TOG-2 in the UK. Instead, the design had originally planned to simply copy the suspension from the Tiger but, as the weight of the design ballooned from 100 tonnes to around 150 tonnes, even a strengthened form of Tiger suspension had to be abandoned. Instead, the designers from Porsche focussed their attention on multiple small wheels to spread the load and these were arranged in groups of bogies running on a very wide track to spread the weight. This was fine in theory, except that no one had attempted to make an effective suspension system for a tank of this weight before.
The original ideas for the suspension back in October 1942 had 12 double road wheels per side using units copied directly from the Tiger (P) but, by January 1943, this was down to just 10 sets. These pairs of road wheels were suspended between the inner hull and the outer skirt of armor on a large support pin (Tragzapfen). This was the primary reason the side armor had to be made in one piece until the suspension was redesigned. When, in March 1943, a new system of Laufwerk (suspension and road wheels) was adopted, it took the loading off the side armor, allowing for the manufacturing process to the improved (notwithstanding the fact that the first vehicles were too wide). That system came too late for the first 6 hulls but, as hull 7 had not yet been assembled, the changes could be adopted from number 7 onwards.
Further suspension improvements followed in April 1943 with the previously welded suspension supports (Trägerstützen) being replaced with ones that bolted onto the hull instead. However, this meant boring holes through the armor plate in order to accommodate longitudinal supporting arms for the torsion bar suspension.
The design for the track which was shown on 21st January 1943 differed from the earlier work on suspension for the tank to take into account the growing weight of the machine. Developed by Dr. Porsche, the system was unique with no compatibility with the suspension from any other tank. This new suspension system (neue Laufwerk) had removed the need for the side skirts to bear some of the suspension load and also allowed for an additional set of bogies to be added to the design. Running on a new design of track 1,100 mm wide, this arrangement allowed for a better distribution of weight to the track which in turn allowed for improved crossing of soft ground. Not only did this new compact design allow for an extra bogie, it also reduced weight by a significant 4 tonnes. These new suspension units (designed by Porsche) were not to be built by Porsche or Krupp, but by Škoda as a subcontractor.

Improved volute suspension units fitted in March 1944, replacing the earlier type in which the internal rubber rings had failed during testing in January 1944. These units were all made by Škoda. Source: UK National Archives and Frohlich
The wheels, fitted with a steel tire, contained a heavy rubber ring within them as a shock absorber and were identified, even before testing, as a weak point. They were a hang-over from the urgent need to change from torsion-bars to volute spring suspension in February 1943 in order to create space for the flame projector system. Dr. Porsche always preferred torsion bars and this was the original and favored system for the Maus, but with the flame-projector requirement forced upon him at very short notice, he complained that he lacked the time to test a new type of heavier torsion bar system and reluctantly agreed to what he considered to be an inferior system of volute springs. Tested in January 1944, the internal rubber rings in these wheels failed after only a short distance and were replaced with an improved type of wheel in March 1944.

Replacing the original road wheels with an improved design (shown being fitted) in March 1944 involved jacking up the Maus by means of 3 large hydraulic jacks. During this time, the engine, generators, motors and final drive were all removed and inspected. Each of these new units weighed 800 kg. Source: Frohlich
The first hulls, which were in the process of being made, were to have holes for the bracing arms (Streben) bored into the hull sides and side skirts – a lengthy process. This redesign meant that holes would still have to be bored out of the inside of the side skirts and in the hull, but they would only be bearing the load of the bolts for the horseshoe-shaped sections (Träger Stütze – suspension supports) for holding the Streben, meaning that the lower side skirts could be made thinner and could be welded onto the upper section. The ends of the bolts holding those horseshoe-shaped mounts for the Streben are visible along the bottom edge of the side skirt.

Original method (left) of holding the bracing arm (Streben) for the external torsion-bar suspension (laufwerk) involving boring holes at both ends, and modified method (right) (February/March 1943) of holding the bracing arm for the volute spring suspension. Not to scale. Source: Author

Cross-section of the sponson area with the track-run below. Clearly shown is the Streben for the support of the suspension unit and the new type of horseshoe-shaped mounts holding it to the hull and outer armor. Source: US Army Intelligence Bulletin March 1946

Pair of incomplete Maus hulls stacked on top of each other (the bottom one is upside down) found by the Allies in 1945 showing the holes bored through the lower side armor for the horseshoe-shaped supports for the Streben. Source: UK National Archives

Composite image edited to show the upside-down horseshoe-shaped holders for the ends of the Streben on the inside of the side skirts. Source: Jentz and Doyle, and Frohlich

Armament

Right from the start, the goal was to create a 100-tonne tank with a heavy gun and, on 14th April 1942 (a month after the program started), the gun in question was identified as the 15 cm L/40. This gun used unitary (single-piece) cartridges instead of a shell with separate bagged charges. The desire was to be able to fire 4 to 5 times per minute, but during the development of this weapon, it was decided to reduce the desired shell weight from 43 kg to 34 kg and to compensate for this with an increase in muzzle velocity to 845 m/s.
Just as with the early concept for the vehicle which became the Jagdtiger, there was an initial expectation for the tank to be able to operate in indirect fire mode, which is to act as field artillery. This is evidenced by the fact that, although the elevation limits for the gun were -8 to +15 degrees, it was desired that the gun should also be able to be elevated to +40 around its entire arc of rotation (360 degrees). There could be no reason for this except to act in an indirect fire capacity and this turret was to be offered to Porsche for use in its VK 100.01 by the middle of May, leaving just 3-4 weeks to design it. Krupp’s engineers planned another turret design based around a different gun, the 12.8 cm L/50, which could fire a slightly lighter 29.3 kg shell at 810 m/s.
By the middle of May, it was expected that even these guns were not going to be able to deliver the anti-armor punch which was desired of this new tank and caliber lengths of L/60 and L/72 should be considered even though, as of that time, those guns did not exist. A month later, the guns had changed again, with Porsche suggesting a 15 cm L/37 or 10.5 cm L/70 gun, with Hitler selecting the 10.5 cm gun for reasons of improved ammunition stowage and a better rate of fire. At this time, Hitler was against the adoption of a second turret with a 7.5 cm gun.
In July 1942, Krupp was issued a contract by Wa Prüf 6 for the June design under the name ‘Pz.Kpfw. Mäuschen’ to mount a pair of guns in a single mounting in a single turret. The guns in question, despite Hitler’s selection of a 10.5 cm gun, were the 15 cm KwK. L/31 and the 7.5 cm Kw.K. L/24. The combination of these guns would allow the Mäuschen to deliver effective indirect high-explosive shellfire, but also direct fire against armored targets. Both guns were to be able to achieve an elevation of -7 to +25 degrees, although a British examination in 1945 states elevation was limited to +23 degrees.
At the start of December 1942, Hitler ordered a trials vehicle to be ready for summer 1943 but wanted information on the performance of the 15 cm gun, the 12.7 cm Naval gun, 12.8 cm Flak gun, and a new (as yet unbuilt) 12.8 cm gun with a longer length.
When, on 3rd January 1943, Hitler met with Armaments Minister Albert Speer, he ordered the Mäuschen into production by the end of the year but was still debating what the final gun was to be. The candidate guns were essentially the same as before, albeit the 12.7 cm Naval gun idea was dropped. Hitler was still favoring the 12.8 cm gun option, although a 15 cm gun option was to be projected too and the secondary 7.5 cm gun was still being retained.
By January 1943, the gun for the Maus had been selected. It was to be a 12.8 cm gun, 55 calibers long and capable of firing new ammunition to achieve the performance required against enemy armor. An option was retained to switch out the 12.8 cm gun with a 15 cm L/38 gun to provide additional high-explosive firepower and both options could be fitted on the same carriage, making exchange simple. Whichever gun was used, it was to be paired with a 7.5 cm L/36 gun. Originally, the secondary armament was intended to be a 7.5 cm Kw.K. L/24, but this was changed out prior to January 1943 with the slightly longer version. The ammunition remained unchanged but the addition of the slightly longer gun meant a small increase in anti-armor performance. An additional weapon planned in January 1943 was a 2 cm Flak gun built into the turret.
In December 1942, before the design of the Maus was even approved, a supplemental system to protect the tank from enemy infantry and to attack enemy positions was proposed and Porsche was ordered to add this to his design on 2nd February 1944 by Col. Haenel. At a meeting held in Stuttgart on 10th February, representatives of all of the manufacturers complained about this late addition to the design and that the added complications would slow down production. This Flammenwerfer Anlage (flamethrower system) was based on the Gross–Flammenwerfer (heavy flamethrower) system which had been installed in a Panzer III, but a long-range of 150 to 200 m was wanted for the flame-projector on the Maus.
The Gross-Flammenwerfer as used on the Pz.III was made by Hermann Koebe of Feuerwehr-Geräte-Fabrik of Berlin, a manufacturer of fire-fighting equipment, and they were asked if they could make this new long-range flame-projection system. They responded that they could not, as even a 100 m range necessitated a flame-nozzle (Spritzkopf) 22 mm wide and used 33 liters of fuel per second propelled by a 30 hp engine driving a pumping system. To project a flame even further would require a narrower (12-14 mm) nozzle, but to add an additional layer of complexity the Maus was not to have one flame-projector nozzle but two, one on each side. Consideration had actually been made to mount those nozzles in the turret (abandoned to keep turret-weight down) and at the front of the tank’s hull, which would assist with the range, although it would prevent the use of flame to keep enemy troops from the sides of the tank. Mounting the system on the front would require additional armor protection to prevent damage to the nozzles and to the fuel system of the tank but even at the back, they were still substantially armored under a 150 mm thick cowling. Altogether, this system weighed an extra 4.9 tonnes, and added significant complexity to the design of the tank, not least of which was directing the flame projectors. That was to be done by an indicator for the radio operator in the front of the hull to control the direction and use of the flame projectors, but this complexity and the added weight was simply an unnecessary complication for the tank. Despite an attempt to reduce the weight to just 2 tonnes by reducing the armor over the projectors from 150 mm to just 30 mm on the front, the problems of the system, the already tight space requirements and the growing weight of the Maus made this device highly impractical.
In May 1943, the entire flame projector idea was rightly abandoned. It had caused one other key change in the design of the Maus which was to make it a lot heavier. The torsion bar suspension of the original design needed an additional bogie to bear the weight, but with a lack of space for it, the torsion bars were replaced with a volute spring-type suspension instead.

Front crew station for the driver (left) and radio operator (right). Note the escape hatch in the floor in front of the radio operator’s seat. Source: Frohlich
Redesigning the turret to maximize space created almost as many problems for the main armament as it solved. The main armament was decided for the Maus around a simple 3-weapon standard. The main gun was a 12.8 cm gun which was to be interchangeable with a 15 cm gun, a secondary 7.5 cm gun (long enough so that gases from the muzzle did not enter the air intakes on the hull roof below), and a forward-facing machine gun. These gun choices had come about as a result of needing to perform particular roles and had been variously modified in order to avoid technical problems (the lengthening of the 7.5 cm gun), to increase muzzle velocity (longer gun options), and to allow for the use of saboted ammunition (removal of the muzzle brakes).
The ammunition was modified to support these changes through the adoption of unitary ammunition (single-piece cased ammunition rather than two-piece ammo with shell and a separate propellant).
However, the 7.5 cm gun used the same ammunition as an L/24, which was predominantly hollow-charge ammunition (HL-Granate). The general high explosive 7.5 cm shell (Granate) was considered unsuitable and even the armor-piercing Panzer-Granate (Pz.Gr.) 39 shell was considered poor. More than 50 mm of penetration was required of the L/36 and it was expected that using the Pz.Gr.39, this longer 7.5 cm gun would be able to achieve that. Shells which were of ‘second quality’ (not good enough for the 7.5 cm Pak 40) could, therefore, be used for this gun.
Whilst existing shells were available for the 7.5 cm gun, new shells were needed for the 12.8 cm gun and, by March 1943, development of shells for this gun included a full-calibre armor-piercing shell APCHE-T (Vollkaliber-Panzer Granate), saboted armor-piercing shells (Treibspiegel Panzer-Granate), hollow-charge high explosive (HL-Granate), smoke (Nebel-Granate), anti-concrete shell (Be-granate), high-explosive (Sprenggranate), Brand-Granate, incendiary (L’spur mit brandsatz), and a leuchtgeschoss. All of the rounds were to be fitted with a tracer (L’spur) able to provide tracing of the shell out to 3,000 m. Another full-caliber 12.8 cm anti-armor shell, a ballistic-capped armor-piercing shell, would follow later on (APBC-HE-T).
An important note on the 12.8 cm gun is that, right from the start of the development of a main gun for the project, preference had been given to the use of unitary ammunition – a case and shell combined into a single piece. Firing tests conducted on 29th April 1943 compared the rates of fire between unitary and two-piece ammunition (case and shell separate) for a 12.8 cm gun (in this case the 12.8 cm Flak 40) in a wooden model of the turret to evaluate the differences. The results of firing just 15 rounds of each confirmed that unitary rounds were preferable. On 29th June 1943, unitary ammunition was ordered for the 12.8 cm Kw.K. (Maus) L/55, but only for 300 rounds, with 100 to be delivered by 15th July 1943. The reason for this low number of rounds was due to production problems associated with the cases (Patrone Huelsen) for the shells and plans were put into place for two-piece ammunition to be used after this date for the 12.8 cm Kw.K. (Maus). This also meant that later vehicles would need modifications made to the ammunition stowage arrangements. By the end of 1943, with the serial production cancelled, the Maus became a low priority and, although the 12.8 cm Kw.K. 44 (Maus) gun was fitted as planned, the unitary ammunition did not join it. Instead, the Maus was fitted with racks for two-piece shells, with the shells stowed separately from the propellant-containing cartridges at the back of the turret. Shells (unitary) for the 7.5 cm gun were stowed in the front right of the turret, just to the right of the gun.

The breach of the 7.5 cm Kw.K. 44 L/36 on the right-hand side of the turret looks minute next to the enormous bulk of the 12.8 cm gun (left). The ammunition for the 7.5 cm gun is located conveniently next to the gun. Source: Jentz and Doyle
Ammunition for the 15 cm gun was not as complicated, with high-explosive (Sprenggranate), hollow-charge (HL-Granate), armor-piercing (APCBCHE-T), semi-armor piercing (SAP)(Halbpanzergranate), and an anti-concrete shell (15 cm Granate 19 Rot Beton.). The requirements for the anti-concrete shell for the 12.8 cm gun (and by extension for the 15 cm gun) were that it should be able to breach a reinforced concrete wall up to 4 m thick, a substantial demand but one which would enable to Maus to attack even the heaviest infantry and gun positions and knock them out. This focus on anti-concrete performance and the ability to fire sabotted shells shows that the purpose of the primary armament was to take out bunkers and heavy enemy armor, whilst the 7.5 cm secondary gun was for light targets only, reducing waste of the larger shells. Production of the 15 cm Kw.K. L/38 for the Maus was slow and, on 8th June 1944, the contract for production was canceled, with only two gun tubes completed.

Weapon Role Performance
Machine gun
(M.G. 34 or M.G. 42)
Anti-infantry n/a
7.5 cm KwK. 44 (Maus) Light-targets and open positions 50 mm with Pz.Gr.39
12.8 cm Kw.K. L/55 Anti-heavy armor / anti-concrete 4 m concrete with anti-concrete shell
245 mm @ 1,000 m / 30 deg. with 8.8 cm Triebspeigel-Geschoss mit H-kern at 1,260 m/s
15 cm Kw.K. L/38 Anti-heavy armor / anti-concrete >4 m concrete with anti-concrete shell*

Note:
* Estimated anti-armor performance of the 15 cm anti-concrete shell

The primary armament, the massive 12.8 cm Kw.K. 44 (Maus), was, in spite of its huge size, a good fit for the turret and able to elevate between +24* degrees and – 7. (* British examination in 1945 of the gun cradle showed the elevation limit to be 23 degrees). Mounted to the left of the secondary armament was a mount for an M.G.34, although Wa Prüf 6 requested an M.G.42 instead. Stowage for ammunition was a large task. 85 rounds of ammunition for the 7.5 cm gun were carried, as an additional stowage for 26 rounds was added between June and July 1944.

M.G. 34 mounted on the left of the 12.8 cm and 7.5 cm guns. It was mounted independently. Source: Jentz and Doyle

Summary of Guns considered from April 1942 onwards

Gun Approximate Date Range Note
Primary Armament 10.5 cm L/70 June 1942 to September 1942 Hitler’s choice June 1942
12.8 cm L/50 April 1942
12.8 cm L/55 January 1943 Using special ammunition can achieve 250 mm of penetration at 1000 m / 60 deg
12.8 cm L/60 April 1942
12.8 cm L/61 Shaped charge ammunition, 8.8 cm Tungsten core, saboted 10.5 cm penetrator, and various propellants to be tested to find suitable anti-armor ammunition
12.8 cm L/70 Shaped charge ammunition, 8.8 cm Tungsten core, saboted 10.5 cm penetrator, and various propellants to be tested to find suitable anti-armor ammunition
12.8 cm L/71 April 1942
12.8 cm L/? October 1942 to
December 1942
Type 205 concept drawing
12.7 cm Naval December 1942
12.8 cm Flak December 1942 Sectional gun which could not be used without modification
Alternative Primary Armament 15 cm Kw.K. L/31 July 1942 to December 1943 16 km range
Penetration
190 mm / 30 deg. /1000 meters
15 cm Kw.K. L/37 June 1942 to
October 1942
Slow rate of fire, inadequate space for ammunition
Typ 205 concept drawing
15 cm Kw.K. L/38 January 1943 Alternative mounting to 12.8 cm L/55 on the same carriage in Maus-Turm
15 cm Kw.K. L/40 April 1942 Unitary ammunition
Secondary Armament 7.5 cm Kw.K. L/24 July 1942 to
December 1942
Secondary armament – 7 km range
7.5 cm Kw.K. L/31
7.5 cm Kw.K L/32
7.5 cm Kw.K. L/33
December 1942 Made longer than L/24 to avoid gasses entering the engine and cooling gratings on the hull roof
7.5 cm Kw.K. L/36 Prior to January 1943 Same ammunition as the 7.5 cm L/24
Other Guns 2 cm Flak January 1943 Built-in anti-aircraft gun
3.7 cm Flak May 1943 Additional mini-turret on top of the primary turret with 3.7 cm AA gun
Flammenwerfer Anlage (flamethrower system) December 1942 to May 1943 Improved (longer range, 150-200 m) version of the Gross–Flammenwerfer (heavy flamethrower) system on the Pz. III. Consideration given to mounting it in the turret, front of hull, and rear of hull.

Note:
The 7.5 cm L/36 was only rifled to L/32 length due to fabrication limits on the rifling in 7.5 cm gun tubes – an extension was added 4 calibers long to extend the barrel from L/32 to L/36.
British examination in 1945 of the 7.5 cm L/36 gun showed it to actually be 7.5 cm L/36.5

Specifications for shells for 12.8 cm Kw.K. 82 (L/55)

Shell Weight (kg) Muzzle Velocity (m/s)
12.8 cm Pz.Gr. 43 (Medium charge) 28.3 kg 750 m/s
12.8 cm Pz. Gr. 43 (Full charge) 28.3 kg 920 m/s
12.8 cm Spr.Gr. Flak 40 (Medium Charge) 26 kg 750 m/s
12.8 cm Spr.Gr. Flak 40 (Full Charge) 26 kg 920 m/s
12. 8 cm Spr.Gr. L/5 (Medium Charge) 28 kg 750 m/s
12.8 cm Spr.Gr. L/5 (Full Charge) 28 kg 920 m/s

Trials

With all work on Maus development over by the end of 1943, all that was left of the program was a contract for a pair of hulls (one unfinished) and for a single turret (finished but needing modifications, along with half a dozen unfinished armored hulls.
The completed hull, now at Böblingen for trials, was not going to wasted despite the serial production being canceled. A program for these trials was set on 1st November 1943, but without a turret, a weighted mockup would have to be used to simulate the loading on the hull. This mockup turret (Ersatzgewicht) was a crude affair, roughly similar in shape and size to the Maus Turm but unable to rotate and held in place by cross pieces which were simply tightened up against the underside of the 2,959 mm diameter opening in the hull for the turret ring* to hold it in place.
(*A British examination of the hulls and turrets in 1945 found the opening in the hull for the turret ring to be 2959 mm in diameter and the actual basket of the turret to be 2,388 mm in diameter)

Maus hull 1 with Ersatzgewicht ‘turret’ during trials at Böblingen. Source: Jentz and Doyle
Trials started extremely well on 15th January, with a 2 km off-road trip showing the extreme ease and accuracy of steering. During travel off-road on soft clay soil, despite its enormous bulk, the Maus only sank 50 cm into the ground, yet still managed to steer and drove through it successfully.
Work at Böblingen to finish the interior took place in the second half of January 1944. After that it undertook its first successful trial and was then back on trial on 31st January. Here, during this test, the first problem was found. The rubber rings within the wheels – something which had already been identified as a weak point, started to fail under the load after just a 14 km journey, of which the 9.4 km on a hard surface were likely responsible. New and improved road wheels were already on order despite the existing orders for no further development on the Maus to take place. Here though, Porsche may have been a little bit disingenuous with the high command as, whilst the ‘Maus’ was now effectively dead, he was calling the vehicle by his original designation of Type 205 once more. The driving system from Porsche had been proven effective with the ease of steering and this was reinforced on 3rd February when the turning of this massive vehicle was tested. It could turn both within its own length, by reversing one track and driving the other forwards, or in a minimum radius of 14.5 m for a full 360 degree turn when driving forwards on just one track.
Dr. Porsche must have been very proud of his design work, as it had proven itself to work very well and the final work on the hull, such as welding on towing eyes, was completed during February 1944 with a 2-day off-road trial personally conducted by Dr. Porsche on 8th and 9th February 1944.
During this time, the otherwise grey-colored Maus hull and Ersatzgewicht ‘turret’ were painted with a rough three-tone camouflage scheme consisting of a base coat of Dunkelgelb RAL 7028, over which green (Olivgrun RAL 6003), and red-brown (Rotbraun RAL 8107) stripes were painted, along with a small backwards Soviet hammer and sickle motif on the sides of the hull, possibly to confuse any observers about the origins of this machine. It was painted in this way that Type 205/1 (Type 205 hull number 1) became stuck in very soft swampy ground on the testing ground. That area of the ground was avoided by all tanks but the driver, not knowing his way around, stumbled into it and the hull sank to about half its height in the soft mud. Extricating this enormous tank was easier than might be imagined, as it required only for the mud at the back to be dug out and some timbers placed under the tracks for it to free itself under its own power.
Despite this, the photos of the Maus stuck in the mud and subsequently being cleaned appear regularly in books and online (incorrectly) as evidence as to why the Maus was a failure, as it would sink into the ground.

15th to 17th March 1944. The notorious ‘stuck’ photo (left) and being cleaned (right) are frequently disingenuously used as evidence for why the Maus was a failure despite this taking place months after the contracts for production were canceled and in spite of successful tests. Source: Jentz and Doyle

Hull number 2 with turret number 1 (unpainted) during tests at Böblingen. Source: Jentz and Doyle
Tests on and improvements to the turret were carried out throughout July 1944 and the finished machine was an imposing sight. It should be noted at this point that there were both external and internal differences between the two Maus hulls at Böblingen. Hull 1 had three shell deflectors on the roof of the hull to help eliminate the shot-trap which Porsche had previously complained about. Hull number 2 only had the single wide deflector on the hull. The second difference is the engine. Both vehicles had originally been fitted with the Daimler-Benz MB 507 engine but, in February 1944, hull number 1 was refitted with the Daimler Benz MB 509 motor.

The completed No.2 vehicle with turret number 1 painted in its 3-tone camouflage pattern during testing at Böblingen. Source: Jentz and Doyle
The tests were, on the whole, highly successful. The Maus could be driven easily and with a fine degree of control, ground pressure and traction were acceptable and the drive system, in contrast to many other German heavy vehicles like the Tiger II and Jagdtiger, was more than sufficient for the job, especially after the improved engine had been fitted. There had been problems, the sort of thing expected from trials, requiring changes to a few features such as periscopes to improve visibility, the driver’s seat, ammunition stowage, the traversing mechanism, and those original wheels which had failed. The engine had also not worked as well as was wanted and was suffering valve damage although it is not clear if this was a manufacturing problem or as a result of stress on the engine during testing.
On top of this, the original 1,100 mm wide flat-plate track (plattenkette) had proven unsuitable and was replaced with a new track plate with removable ice cleats which were produced by Škoda (Griffigere Gleiskette). On the whole, there was nothing out of the ordinary for testing and the vehicle was able to move and maneuver adequately under its own power yet, despite this, on 19th August 1944, all work on the Type 205 (both vehicles) was stopped and the Krupp workers were diverted to more urgent work.

Both Mäuse seen together with V.2 and Turm 1 closest to the camera. V.1 with the E-Turm is in front of it. Source: Jentz and Doyle
Despite this order, some work continued to be done on the Maus, including on the new engine, which had proven to be problematic. On 1st December that year, Daimler-Benz had acknowledged that a new engine for the tank, the MB 517, was nearly ready. It had been ordered by OKH but then canceled and left unfinished – 2 weeks’ work would see it operational but Daimler-Benz was reticent about giving the engine away. Obtaining that MB 517 engine for the Maus would at least mean that both tanks had the same engine. Both vehicles, Hull 1 with the E-turm amd Hull 2 with Turret 1 were taken from Böblingen and sent to Kummersdorf in the second half of 1944. Here, at the end of the war, Vehicle 2 with Turret 1 was blown up. When Soviet forces captured Kummersdorf and the blown-up Maus hull, as well as the complete but E-turreted second vehicle, were found, they conducted some firing trials on the second vehicle. At least seven hits were obtained on the side of the second vehicle, including two on the sides of the E-Turm, some or all of which were using shaped charge ammunition. The front of the hull was also subject to being fired at with at least 10 hits of the glacis, lower front, and track guards respectively.
After these seemingly impromptu trials, the Soviets recovered the turret from the wrecked vehicle and installed it on the first hull (still bearing the scars of the firing trials) and shipped it back to the Soviet Union for further examination. There, it eventually had all of the interior stripped out, and the engine, motors, and transmission were all removed, leaving an empty armored shell. The vehicle, thankfully, survives to this day and is on display at the Patriot Park Museum at Kubinka near Moscow.

Soviet troops using captured German halftracks to recover the turret of the Maus. Source: Unknown

Maus (hull number 1, turret number 1) as rebuilt by the Soviets, heads to its new home at Kubinka circa 1946, still on its spezial Transportwagen. Ahead of it on the train is the no less special prototype Sturmtiger. Both vehicles survive to this day at Kubinka’s Patriot Park exhibition. Source: Unknown

Maus Timeline – Key Events

Date Hull (Wanne) Turret (Turm) Event
5/3/1942 100- tonne Panzer contract to Krupp
21/3/1942 100-tonne Panzer contract to Porsche
23/6/1942 Initial drawings from Porsche
17/7/1942 Pz.Kpfw. Mäuschen turret contract issued
5/10/1942 Type 205A
November 1942 Hitler orders 5 vehicles
December 1942 Maus Turm contract issued to Krupp
15/12/1942 Krupp Tiger-Maus terminated
3/1/1943 Trio-production agreement between Porsche, Krupp, and Alkett
21/1/1943 Full sized mockup shown
21/1/1943 Turret and hull drawings ready (ahead of schedule which was March 1943)
2/2/1943 Order to add heavy flame-projector system
10/2/1943 120 vehicles ordered
10/2/1943 Complaints from manufacturers over the late addition of the heavy flame-projector system
Late February 1943 Abandoned external torsion bar suspension and adoption of volute spring suspension
6/4/1943 Albert Speer inspects full-sized Maus model
May 1943 Suggestion to adopt ZF electromagnetic gearbox instead of electric drive system is not adopted
May 1943 Order increased to 135. First 2 to be ready by November 1943
End of May 1943 Manufacturing tolerances tightened to avoid oversize
May/June 1943 Contract issued for 135 series production vehicles and 6 prototypes (141 total)
June 1943 Gen. Guderian adjusts order to just 5 tanks (total)
1/7/1943 Order amended to 5 Maus per month (a production speed cut of 50%)
July 1943 Complete turret mockup ready
7/7/1943 1 Armored hull welding complete
12/7/1943 Serial numbers issued for production
16/7/1943 Daimler-Benz MB509 engine arrives at test laboratory for testing. Modified to run inverted and on low octane fuel.
1/8/1943 2 Second hull ordered – will be fitted with Daimler-Benz MB517 engine
4/8/1943 Allied bombing of Krupp (Essen) slows production
26/9/1943 1 Hull number 1 transferred from Krupp to Alkett for fitting of drivetrain – some machining still required
27/10/1943 all all Development of Maus cancelled with order for 120 changed to a single vehicle
1/11/1943 1 – 2 1 Trials programme set
5/11/1943 all all Series production cancelled
5/11/1943 1 Contract for 6 turrets reduced to complete just a single turret
12/11/1943 1 – 2 Contract reduced from 6 to 2 hulls
22/12/1943 1 Finished at Alkett
28/12/1943 1 Test drive at Alkett
8/1/1944 2 Shipped from Krupp to Alkett
10/1/1944 1 Ordered to be shipped to Böblingen for tests
11-13/1/1944 1 Shipped from Berlin to Böblingen via railway on a 14-axle Spezial Transportwagen
14/1/1944 1 Unloaded at Böblingen and drove 5 km to the workshops without problems
15/1/1944 1 E First trials of hull number 1 (Typ 205/1) – very successful
Mid. January 1944 2 Assembly work at Alkett halted
16-30/1/1944 1 E Assembly and fitting of other interior components
31/1/1944 1 – 2 n/a Component parts (armored periscope housings and gratings for hulls 1 and 2 (Typ 205/1 and 205/2)) delivered to Alkett by Krupp
31/1/1944 1 E Off road trials – travels 14 km including 4.6 km off road. Failures found in rubber rings in the road wheels.
3/2/1944 1 E Further driving trials restarted. Wa Prüf 6 representative in attendance
4-25/2/1944 1 E Vehicle completed including addition of towing eyes
7-8/2/1944 1 E Off-road driving trials for Dr. Porsche for 6.4 km (64 km total).
7/2/1944 2 Assembly work ordered transferred to Böblingen
8/2/1944 1 E Daimler-Benz MB509 engine installed
7-10/3/1944 2 Shipped to Böblingen for completion
10/3/1944 2 Hull number 2 (Typ 205/2) arrives at Böblingen – towed by hull number 1 to the workshops (~5 km) involving a 12% incline and icy road – successful
13/3/1944 Assessment at Krupp that production could restart
18/3/1944 3 – 7 Hulls 3 – 7 available at the armor workshops – welding complete
20/3/1944 1 E Improved road wheels fitted
23/3/1944 2 Porsche requests second turret from Krupp
1/4/1944 Production, if restarted, could deliver 2 vehicles per month
1/4/1944 3 – 7 2 – 7 Can be completed due to bodies already finished
15-17/4/1944 1 E Trials crossing 1 m deep streams and traversing 45% slopes – successful
Vehicle later became stuck in a swampy area and had to be partially dug out – freed itself under its own power
New road wheels fitted
Mid. April 1944 1 Assembly at Krupp finished
3rd May 1944 1 Shipped from Krupp to Böblingen for modification and mounting – turret arrives bare with guns and fittings separate
4th May 1944 1 Unloaded at Böblingen
7-8/June 1944 2 1 Turret number 1 mounted on Hull Number 2 at Böblingen
June 1944 2 1 Work on turret interior
June 1944 Daimler-Benz MB517 engine arrives at Böblingen
9/1/1944 1 Turret number 1 assembly finished
23/6/1944 to 2/7/1944 2 1 Under repair – improved ammunition stowage
10-17/7/1944 2 1 Tests on electrical turret traverse
July 1944 2 1 Driving trials – tears up cobblestones
25/7/1944 3 – 7 2 – 7 Wa Prüf 6 gives permission to scrap leftover turrets and hulls
19/8/1944 1 – 2 1 All work on Maus ordered to stop
September 1944 Tests on MB517 show it is superior to MB509
Late 1944 1 – 2 1 – E Both vehicles moved to Kummersdorf
February to March 1944 2 1 MB509 installed in vehicle number 2 started and breaks crankshaft due to bad alignment of engine when fitted
Mid March 1945 2 1 Replacement MB517 engine sent to Kummersdorf for vehicle number 2 to replace broken MB509 engine – technicians from Porsche attend Kummersdorf to fit engine
April 1945 2 1 Blown up at Kummersdorf
After May 1945 1 E Firing tests against Maus and E-turm at Kummersdorf
March to April 1946 1 1 Turret 1 mounted on hull 2 by Soviets and shipped to USSR
4/5/1946 1 1 Arrival at Kubinka

Note:
Typ 205/1 is hull number 1
Typ 205/2 is hull number 2
‘E’ is the ‘Einsatz Gewicht Turm’ used to simulate the weight of the actual turret


Allied soldiers at the captured Krupp factory in May 1945. Behind him are the hulls of two Maus tanks and two turrets. The turret directly behind the soldier is serial number 351452, the second Maus turret. The other turrets belong to Tiger Is and are not part of the Maus program. Source: Frohlich (left) and Jentz and Doyle (right)

Maus hull serial number 351453 (Number 3 hull) laying unfinished at the Krupp plant in 1945. Source: Jentz and Doyle

Maus Redux

A final element in the story of the Maus is a report dated 13th March 1944, 4 months after serial production had been canceled, by Dr. Muller of Krupp stating that production of the Maus hulls and turrets could be restarted if required. Five days later, on the 18th, Krupp reported that 7 Maus hulls had been finished by the armor workshops (Panzerbau) and that it had enough armor plate on hand to finish another 8 hulls.
On top of this, the order to send unused armor to the Sturmgeschütz program back in October 1943, immediately prior to the Maus program being canceled, seems to have been interpreted fairly liberally, as there was clearly a lot of armor plate still available. There were enough, in fact, for about another 30 hulls and turrets as well as 15 more hulls and 9 turrets’ worth of cut plate. Those 30 hulls and turrets’ worth of armor should have been sent away to the Sturmgeschütz program, but having retained them at Krupp for whatever reason, in spite of no orders for them, Krupp now had enough material to fabricate 45 Maus hulls and 39 turrets from that material plus the 7 finished hulls and armor prepared for 8 more, a total of 60 or so hulls and 39 turrets. On 23rd March 1944, despite the program having been canceled, Wa Prüf 6 was under orders from Hitler to accelerate testing and to resume development of the Maus.
Porsche contacted Krupp around this time to request not only delivery of the second turret for the existing Maus hulls (two hulls one turret), but also for a follow-on design of a turret known as Maus II.
On 1st April 1944, when looking at restarting Maus production, it was determined that an additional 200 workers would need to be allocated and that even then the rate would be just one or two tanks per month. This would be restarting production from vehicle 8 onwards as, by this time, 2 hulls had been finished and shipped out leaving 6 partially completed hulls awaiting scrapping. Approval to scrap hulls 3 to 6 was given on 27th July 1944. There were to be no more Maus completed, 2 had been built and were going to be tested.
The left-over pieces though were not scrapped. A British report from 1945 shows that three Maus hulls and turrets were found at Meppen (Krupp’s proving ground) with the hulls on their sides and turrets upside down. The examination showed the highest number found to be number 6. A complete 12.8 cm Kw.K. 44 monobloc gun with coaxially mounted 7.5 cm Kw.K. 44 monobloc gun (on the right) was found on the same range a few miles away. The British examination of records at the range showed that this 12.8 cm Kw.K. 44 (Maus) had been rechristened ‘12.8 cm Kw.K. 82’ and that ammunition (and presumably that gun) had been delivered in November 1943 and that ammunition was there by at least 3rd January 1944.

12.8 cm gun and 7.5 mm gun on dual mount (left) and what is believed to be the 15 cm gun (the muzzle has been sabotaged) with 7.5 cm gun on dual mount (right) as found on a cradle at the Krupp firing range, Meppen, 1945. Source: UK National Archives


The three recovered hulls and turrets found by the 21st Army Group at Meppen in 1945. It is interesting to note that the turrets had not yet had the roof plates holes cut out for the cupola and hatches. Source: UK National Archives

Variants

Sturmgeschütz (15/17 cm Sturmgeschütz auf Mausfahrzeug)

This was a brief idea from May 1944 to consider how and if a 15 cm or 17.4 cm gun could be mounted on the chassis of a Maus to compete with the same idea based on the E100 hull. Less than a month after being floated as an idea, it was discounted in favor of considering the E100 hull-project instead. No Sturmgeschütz (15/17 cm Sturmgeschütz auf Mausfahrzeug) was ever built and no drawings are known to survive.

Maus bunkers

One of the more unlikely off-shoots of Maus development was the consideration, in late September/early October 1943, to use series-production Maus turrets as static defensive structures. The situation had been forced upon Speer (the Armaments Minister) by a lack of steel-casting capacity for the 12.8 cm and 15 cm Panzerturm (armored fortress turrets) and, as the Maus was designed to be able to mount a 15 cm gun, these turrets might be a solution to the fortress-turret shortage.
The result was that Krupp was asked to prepare a design for such an installation and duly, on 2nd November 1943, it did just that, providing a drawing of a Maus turret (with a reinforced roof) for use on a bunker (Turm ‘Maus’ für ortsfesten Einsatz – Maus turret for a fixed installation). With the cancellation of the Maus turret production just 3 days later on the 5th, the idea became impossible and was abandoned, although quite how realistic the idea was anyway is debatable.

Turm ‘Maus’ für ortsfesten Einsatz (Maus Turmstellung) 2nd November 1943. Source: Jentz and Doyle

Conclusion

John Milson, writing in 1973 about the Maus, questioned just how much the men responsible for the design of vehicles like the Maus really believed in the value of such a machine as a weapon of war. He doubted that they really believed in these projects and, whilst certainly they may have denounced them post-war as ludicrous and wasteful, their actions during the war belie this. Porsche, in particular, was pressing hard for the Maus project right from the start, and even after it was canceled, in order to restart it – hardly the actions of a man who felt it was pointless.
It was clearly felt by many in the industry that manufacturing a technical solution was possible to ensure dominance over the increasingly better armored, better-armed enemy tanks that were being encountered in superior numbers. Dr. Porsche also no doubt reveled in the engineering of the vehicle he had designed and made full use of his political connections to gain and maintain support for the Maus long after its perceived utility was over.
As a piece of engineering, the Maus is impressive in the challenges it created and the solutions presented. However, the size, armor, and firepower were simply an extravagance Germany did not need and could ill afford in terms of time, money, and material. There is no realistic consideration that the Maus, even if produced in numbers, could have made any substantial effect in a campaign or the war. It is far more likely that the ignominious fate which awaited the single finished vehicle would have been shared by any others that were built: namely, being abandoned when it ran out of fuel or broke down and then being blown up by its own crews, a fate which befell many other German heavy tanks. Yet the Maus is still around, preserved at Kubinka and marking the top-end of what a tank could really be in terms of armor and firepower during the Second World War.

The 1st Maus hull mated with the 1st Maus turret as it stands today at the Kubinka tank museum in Russia. While the tank looks complete on the outside, it is almost completely gutted on the inside. Photo by Craig Moore

Sources

Porsche, F. Bericht Uber die Werksorprobung des Typ 205/1 in Böblingen von 11.1 – 3.2.1944
British Intelligence Objectives Sub-Committee. (1945). BIOS report 1343: German Steel Armour Piercing Projectiles and Theory of Penetration. Technical Information and Documents Unit, London.
British Report on ‘Experimental Super Heavy Tank ‘Mouse’ (Pz.Kpfw. Maus)’ – May 1945
CIOS Final Evaluation Report 153. (28th June 1945). Interrogation of Herr Stiele von Heydekampf.
Datenblatter für Heeres Waffen Fahrzeuge Gerät W127. (1976).
Frohlich, M. (2016). Panzerkampfwagen Maus’. Motor Buch Verlag
Jentz, T., Doyle, H. (2008). Panzer Tracts No.6-3 Schwere Panzerkampfwagen Maus and E 100.
Koebe, H. (8th April 2019). Luckenwalde Local History – Koebe factory founded 140 years ago. Maz Online.de
Ludvigsen, K. (2018). Professor Porsche’s Wars. Pen and Sword Publications
Ogorkiewicz, R. (1991). Technology of Tanks. Janes Information Group, Surrey, England
Sawodny, M., Bracher, K. (1978). Panzerkampfwagen Maus und andere deutsche Panzerprojekte. Odzun-Pallas-Verlag, Friedberg, West Germany
Spielberger, W. (1998). Spezialpanzerfahrzeuge des Deutschen Heeres. Motor Book Verlag
Spielberger, W., Milson, J. (1973). Elefant and Maus. AFV Weapons Profile No.61.
US Army. (1953). Technical Manual TM9-1985-3 German Explosive Ordnance (Projectiles and Projectile Fuzes)
US Army. (1950). Project 47: German Tank Losses. Historical Division European Command. US Army.
US Army. (1946). Intelligence Bulletin March 1946. The German Mouse.
US Navy. (September 1945). Technical Report 485-45 – German Powder Composition and Internal Ballistics for Guns. US Naval Technical Mission in Europe Report.
War Office. (25th October 1944). 12.8cm A.Tk. Gun Pak.44 on Pz.Jag. Tiger (Pz.Kpfw. Tiger B Chassis) Sd.Kfz.186 JAGDTIGER. Appendix D War Office Technical Intelligence Summary, No.149 1944.
War Office. (25th April 1945). Technical Intelligence Summary Report 174 Appendix C
War Office. (4th June 1945). Technical Intelligence Summary Report 178 Appendix E
War Office. (27th June 1945). Technical Intelligence Summary Report 180 Appendix D
War Office. (26th July 1945). Technical Intelligence Summary Report 182 Appendix F and G
War Office. (11th October 1945). Technical Intelligence Summary Report 186 Appendix A
War Office. (20th December 1945). Technical Intelligence Summary Report 188 Appendix

Maus specifications

Dimensions 10.085 (9.034 without gun) x 3.7 x 3.649 m
Total weight, battle ready 188 tonnes (50 to 55 tonne turret)
Crew 6 (commander, gunner, 2 x loaders, driver, radio operator)
Propulsion V1 – Daimler-Benz MB 507 V-12 Petrol
V2 – Daimler Benz MB 517 V-12 Petrol 44.5 litre – 1,200 hp @ 2,500 rpm
8 hp auxiliary petrol engine providing power to create overpressure inside, air conditioning, gas filtration, heating, battery charging and for snorkelling
Fuel consumption 3.5 litres per km
Speed (road) 22 km/h
Trench 3.5 m
Fording 2 m (without preparation), 7.9 m (submersible) with snorkel tube fitted
Turret Armor Front – 215 mm rounded
Sides – 205 mm at 30 deg.
Rear – 205 mm at 10 deg.
Roof – 60 mm at 90 deg.
Basket walls – 55 mm
Floor- 93 mm
Hull Armor Front Glacis – 205 mm at 55 deg.
Lower front – 205 mm at 35 deg.
Track guards – 100 mm at 10 deg.
Sponson floor Front – 50 mm at 75 deg.
Sponson floor Middle – 50 mm at 90 deg.
Sponson floor Rear – 50 mm at 85 deg.
Sides Upper – 173 mm at 0 deg.
Sides Lower (skirt) – 105 mm at 0 deg.
Sides hull inner – 80 mm at 0 deg.
Rear Upper – 153 mm at 40 deg.
Rear Lower – 153 mm at 30 deg.
Floor front – 100 mm at 90 deg.
Floor middle and rear – 50 mm at 90 deg.
Roof Front – 103 mm at 90 deg.
Roof Middle – 60 mm at 90 deg.
Roof Rear – 60 mm at 90 deg.
For information about abbreviations check the Lexical Index
Categories
WW2 German prototypes

Mahlkuch Armored Cover

 

Nazi Germany (1938)
One-man tank – None built

Ernst Mahlkuch is not a name synonymous with tanks or armored vehicles, yet he designed an armored vehicle at the height of pre-war Nazi Germany. He designed this vehicle not as the product of a ‘crack-pot’ inventor or an otherwise-untrained engineer, but from the mind of a very competent engineer and one who would amass dozens of patents and designs in his name for a variety of ideas, from flour-weighing equipment to wood-gasifier units for vehicles.
Whilst those designs were well considered and based on some expertise in the field, his idea for an armored vehicle for soldiers was far less well-considered, never received any interest and has, until recently, been forgotten by history. As a product of Nazi Germany, this armored vehicle certainly lacks the presence of the Maus, the fame of the Tiger, or the utility of the half-track, but his design does follow a common trait – an armored vehicle with a low silhouette with the intention of protecting the otherwise unprotected infantry during the attack.

The Company Man

Ernst Mahlkuch, a German national from Post Klützow, Pomerania, (now part of Poland) was an engineer who specialized in industrial machines used for moving and filling bags, balances, and other machines, from the early 1900s and through WW2. Ernst Malhkuch’s family connection to the mill-industry and the Greif mill at Klützow had started with Joann Mahlkuch in 1734 as a miller, producing very high-grade flour. Although the original Greif mill (Greifenmühle) itself dated back to 1100, after the mill burned down in 1891 (a common problem for flour-mills), it was rebuilt and modernized, with Ernst Malhkuch assuming charge of the business. By the outbreak of WW1, Mahlkuch‘s business took a hit with its horses and a lot of the workers taken away for the war effort and with the firm renamed Reichsgetreidestelle (Imperial Breadstuff’s Commission).

Ernst Mahlkuch, mill owner. Circa 1908. Source: Velopack
The firm survived WW1 and, in its aftermath, Malhkuch continued to expand the business with the purchase of electric vehicles in 1920. A second major fire in 1933 destroyed the plant, leading to another rebuild and modernization in 1934.
By 1938, the firm was renamed ‘Greif-Werke’, based in Klützow, and was fully operational by 1941. By the end of WW2, Mahlkuch’s plant had fallen on the wrong side of what was to be the east/west divide and he restarted his mill business in the city of Lübeck instead. The firm changed name one more time in 1997 to Greif-Velox and today is still in operation, making fill-line production systems for industry as Velox Industrial Packaging Systems Inc.

The Vehicle

Quite how or why a man fluent in the engineering of flour and milling machines came to take an interest in armored vehicles is unclear. When this vehicle design was submitted in 1938, the Nazi war machine had already consumed Czechoslovakia and was busily eyeing up Poland. It would be no surprise, therefore, to imagine that, in a heightened time of conflict, an engineer might consider ways in which he could help his nation to victory.

The rather uncomfortably prone crew of Mahlkuch’s design illustrates well one of the numerous problems inherent with this type of design. Source: German Patent DE687780

Crew

Mahlkuch is clear that his armored vehicle was for either just one man or a crew of not more than two. One man would, after all, have to manage the steering, propulsion, command, and fighting power of the vehicle. This was an overwhelming task which was the downfall of a lot of one-man tank designs. As a two man vehicle, this machine would have one man act as the commander and driver, able to observe the enemy and direct the vehicle to where it needed to go, with the second crew-man as the gunner and loader.
In his patent application drawing, Mahlkuch only drew a single operator within the machine, carrying what looks like a fat rifle, but is described as a machine gun. It is safe to assume, therefore, that whether the vehicle was a one or two-man machine, its only armament would be a single forward-firing machine gun.


Illustration of Mahlkuch’s Armored Cover made by Brian Gaydos, funded by our Patreon campaign.

Layout

In common with many one-man tank designs, the layout consists of the occupant lying prone, facing forwards and controlling the steering and propulsion of the vehicle with their feet (their hands being occupied operating the weapon/s). The engine, mounted at the back, was cooled by means of a fan, mounted externally, driving air over the radiator mounted above it. Both the fan and the radiator were exposed at the back and not shown to be covered by the armor of the vehicle.
As expected from a vehicle in which the operator would lie flat, it has a very low profile. It was not more than 600 mm high from the ground according to Mahlkuch, meaning it could conceal itself within long grass. This would also have the significant disadvantage that the driver could not see ahead of the vehicle and very easily drive into a wall or ditch with little or no warning.
Propulsion along the ground is more complicated though, as Mahlkuch shows one system using 4 large 8-paddle wheels about 400 mm high on each side. With little or no ground clearance, these paddle-wheels, described as “shovel-like grippers”, would drag the vehicle over the ground. The floor of the vehicle was smooth, acting as a skid, reducing the friction with the ground and providing floatation on soft ground, but it also meant that the vehicle could easily become stuck on something as simple as a tree-stump. These paddle-wheels were seen by Mahlkuch as providing an advantage over conventional tracks, as they permitted a much more silent approach. The engine was well silenced too, as a covert approach was seen by Mahlkuch as being tactically advantageous.

Top-down view of the arrangement of the vehicle from Mahlkuch. The drive is at the back, supplied by the rear-mounted motor. Source: German Patent DE687780

Armor

No armor thickness or level of protection is specified, but he was clear that this machine should be armored. In order for the armor to have any value against even bullets, it would have to be at least 6 – 8 mm thick. The armor was well rounded increasing the likelihood of deflecting an incoming bullet, a simple way of improving the protection offered by even thin steel plate and was also made with just a single seam, ensuring that no splash could get between the joints in the armor. The single seam in question was the joint between the top and bottom halves of the machine, as it was to be made in just two pieces, with each stamped from a sheet of steel and then attached together. A single, small armored flap was provided in the roof of the vehicle for the operator/s to enter/exit and for ventilation.

Transport

To make the vehicle easy to haul around in between actions, a two-wheeled trailer towed behind another vehicle was envisaged. The range of the vehicle was low in of itself, so would be reliant upon a tractor vehicle to tow it around to a gathering point from where many such vehicles could then be deployed en-masse to attack the enemy.

The transportation cart for Malhkuch’s armoured vehicle. Source: German Patent DE687780

Conclusion

Ernst Mahlkuch had clearly given the design a lot of thought. He wanted to overcome traction problems over the ground and to also make the design simple to manufacture, operate, and transport. Well shaped to deflect bullets and with a very low profile, the design could be seen to maximize the survivability of the soldier/s operating it, but it was a fundamentally flawed concept. Just as with so many other vehicles in this style, the crew would have little or no visibility, could easily become stuck, and were limited in offensive potential to the front, even though they may not be able to see where they might have to fire. Trapped within this low steel box, the crew would have little chance to effectively deliver fire on the enemy, as there was no provision made for firing to the sides and the noise/heat in such a small and stifling space would have been extremely unpleasant. The idea was not adopted by the German military, but it was accepted as a patent. Mahlkuch had filed the application on 9th April 1938, just one month after German troops had occupied Austria. It was approved on 11th January 1940, by which time Germany was already at war with Great Britain and France. No examples were ever made.

Sources

British Patent GB430985 ‘Improvements in or relating to automatic weighers’ filed 28/11/1933, granted 28/6/1935
German Patent DE679858 ‘Gaserzeuge zum Vergasen von festen Brennstoffen im Querstrom’ filed 9/6/1936, granted 20/7/1939
German Patent DE687780 ‘Ortsbewegliche, motorisch angetriebene Panzerdeckung’ filed 9/4/1938, granted 11/6/1940
Greif Velox
Schneider, J. (2013). Herstellerverzeichnis v3.4.

Mahlkuch’s Armored Cover specifications

Dimensions 600 mm high
Crew 1 or 2 (Commander/Driver, Gunner)
Armament One machine gun
For information about abbreviations check the Lexical Index
Categories
WW2 German prototypes

Borgward Light Tank

Nazi germany Nazi Germany (1937-43)
Light Tank – None Built

Most people are familiar, at least in general terms, with patents. They are a means of legally protecting ideas in a commercial marketplace in order for inventors and research institutions to profit from their exploitation. Rather fewer people are aware that even in Nazi Germany patent applications were common and in the crowded military marketplace many designers sought to protect their ideas, which covered a variety of designs and developments. Armored vehicles were no exception to this and, although many armored vehicle-related patents are just for component elements or to illustrate a suspension system on a crudely drawn box for illustrative purposes, sometimes designs for vehicles are also included. The company of Carl Borgward and Co. of Bremen, Germany, requested a patent from the latter category in 1937, for a design of a light tank. On the eve of WW2, this firm, more famous post-war for some of its adventurous and futuristic tank designs, submitted a design for a light tank which was already obsolete. Nonetheless, it is an unusual and rare glimpse of a German vehicle which could have been put into production for WW2 and provides some small insight into the evolution of German armor.

Birth of the Project – October 1937

Borgward submitted three patents relating to the design of a small, fully-tracked tank in October 1937. The purpose of one of the patents was to assist a vehicle in crossing obstacles such as trenches by means of altering the centre of gravity for the vehicle. This was to be done by moving the engine, transmision, fuel tank, and radiator etc. so that the centre of gravity was, at most, just ⅓ of the length of the vehicle from the rear, ensuring that the back end was as heavy as possible. This would keep the nose of the vehicle up as the vehicle passed over an obstacle and improve control for the driver.

‘Militarischen Zwecken dienendes Vollgleiskettenkraftfahrzeug, insbesondere Tank’ from German Patent DE719046(C) 1942. The outline for this vehicle was reused for several patents. The position of the engine and transmission are clear.
Although five wheels are shown in the side-view, only four torsion-bar arms are visible in the overhead view. These torsion bars were submitted as a patent the same day as the other two patents, clearly indicating the connections between them. The bars themselves are interesting in their own right, as they are not full-length bars but are, instead, half-length bars mounted within a common torsion-bar tube with the half-bar from the wheel-station on the opposite side of the tank. The meeting point in the middle was fixed and cut so that the splined ends of each torsion bar met and keyed into the cut section at the centre of the tube.

‘Drehstababfederung fur Lenker von unabhanging gefuhrten Radern von Kraftfahrzeugen’ from German Patent DE720049(C) 1942 showing the internal positioning of the design of the half-torsion bars.
For the internal layout, the vehicle is shown as having the engine on the right, at the back and using a front-mounted transmission with the drive-shaft offset to the right-hand side. On the drawing provided with the application, Borgward marked ‘S’ to indicate the optimal centre of gravity for the design.
The third filing was related to steering for the light tank. Here, the driver was provided with a horseshoe-shaped steering wheel mounted to the underside of the long sloping glacis. This might not look revolutionary or unusual, but it is not actually connected to a steering system in the conventional sense. At the time of this design, a large number of tanks were still being steered by means of brake levers (also known as tillers). Braking one track caused the vehicle to steer in that direction, as drive was delivered to the other. The same was true with this Borgward design, except that, in place of levers, this steering wheel acted as a braking wheel. Turning the wheel to the right moved to linkages from it to brake the right hand track and thus turn to the right. The same was true for a left turn and to go straight ahead all the driver had to do was to keep the vehicle in trim with small movements of the wheel. Certainly, this system was much less tiring for the driver than the manipulation of levers back and forth.

‘Lenkvorrichtung für Gleiskettenfahrzeuge mittels Lenkbremsen’ from German Patent DE700020(C) 1940.

Side Skirts – November 1937

In November 1937, Borgward submitted a design entitled “Schutzeinrichtung für die Gleisketten von Kampfwagen” (English: Protective device for the tracks of vehicles). This design used the same outline of a small tracked vehicle with 5 road wheels mounted on torsion bar arms. The overall shape in cross section is notably uneven across the roof, with these armoured side-plates connected to the top of the hull, angling down to a position approximately level with the top of the track and then moving at a slight angle (nearly vertically) down to a position low on the track run, leaving only about 25% of it visible. This skirt was intended to protect the wheels, tracks and suspension from enemy fire. That design was accepted and published in Spring 1943.

‘Schutzeinrichtung für die Gleisketten von Kampfwagen’ from German patent DE734712(C) 1943 showing the asymmetric hull shape.
It is a second patent filing of November 1937 which gives us the clearest picture of Borgward’s light tank. Filed just two days before DE734712(C), this patent, ‘Schutzschild- und Sehschlitzanordnung für Panzerwagen’, was specifically for a shield for the occupants of the light tank design. The vehicle is clearly the same outline as previous and subsequently drawn for various patents, although the engine is located centrally at the back driving a front (and centrally) mounted transmission in this filing. The extremely small dimensions of the vehicle are readily apparent with the addition of a helmeted soldier seated in the vehicle.

‘Schutzschild und Sehschlitzanordung für Panzerwagen’ from German Patent DE718663(C) 1942 showing the low profile of this light tank.
Two crew members were provided for: a driver on the left, who was protected by means of a flat bulletproof plate, and the machine gunner on the right, who was provided with a curved shield. Interestingly, the patent also shows that this second crew member was provided with a steering control for the vehicle. Both men sit at the same level, either side of the shaft from the engine to the transmission, with just their heads above the level of the top of the glacis, ensuring the very low profile of the tank was maintained.
No armor thicknesses were specified in the patent, but the drawings and nature of the vehicle would be consistent with bulletproof armor only, up to 10-12mm or so.

‘Schutzschild und Sehschlitzanordung für Panzerwagen’ from German Patent DE718663(C) 1942 showing the side by side position of the two crew, machine gun, and both steering wheels.

Adding Wheels – 1938

An addition to this design was submitted in March 1938 by Borgward. Here, wheels were added to the running gear from the tank, although the outline of the body was not shown. These wheels could be raised or lowered by means of a lever operated by the crew. It is mentioned in the patent, but not shown in the drawing, that this system might find utility in ‘wheel-cum-track’ machines – that is vehicles which can travel either on wheels or tracks and switch between the two systems. More usefully though, this wheel system would provide a means for assisting the vehicle to climb over obstacles up to the height of the wheel.

German Patent DE687038(C) ‘Halbgleiskettenfahrzeug’ filed 22nd March 1938. Accepted 21st December 1939. Published 20th January 1940.


What-if illustration of the Borgward Light Tank by Brian Gaydos, Funded by our Patreon Campaign.


One Last Appearance – 1940

This light tank cropped back up again, for the final time, in November 1940, with the filing of a patent for a drive system for a fully tracked vehicle. This new system would eliminate the rattling noise associated with tracked drive systems as well as making the whole manufacturing process cheaper and simpler. Here, the track was fitted with raised sections on the interior face, which were gripped by teeth on the drive sprocket. Those teeth on the drive sprocket were to be fitted as rollers or bearings which would rotate as the track passed over them, eliminating much of the squeaking and rattling with a conventional track system.

‘Gleiskettenantrieb für Gleiskettenfahrzeuge’ from German Patent DE724797(C) 1942.

Other Work

This was not Carl Borgward and Co.’s only contribution, before and during World War II, in relation to tank technology by any means. Other work was for fittings, fixtures, and features to be used on other armored vehicles, although some of the outlines of the vehicles illustrating those ideas could relate to other, unrealized vehicles.
On the same day (4th November 1937) that Borgward applied for a patent for the protective side skirts (Patent DE734712(C)) on an armored vehicle, he also applied for a patent for a new type of track system for vehicles too. Whilst today there have been numerous attempts, and some vehicles in service use continuous rubber track (also known as ‘band-track’), this was new thinking in 1937 and Borgward applied to protect exactly that idea. The patent was not just for continuous rubber-band trackings but also, more unusually, for a steel track made from a single strip of spring steel. This single-piece steel track was flexible enough to go around the wheels, but provided no gaps through which mud or barbed wire could poke. It could be expected, as it would have a larger footprint on the ground than a track plate with holes in it, to also have a slightly better ground pressure but, as a smooth track, it had no grip. To counteract this, Borgward envisaged using steel shoes bolted through the strip-track (whether it is steel or rubber) to form the grips which would allow it some purchase on soft ground and for crossing obstacles. These would have a recess in them to allow for a rubber pad.

‘Laufband fur Kraftfahrzeuge’ from German Patent DE737703(C) of 1943 showing the continuous band-track (made from rubber or steel) with a ‘shoe’ bolted to it.
In February 1938, Borgward submitted a design (in two patents) for a new type of cupola for tanks and armored cars. This consisted of a large cup-shaped dome covering the cupola and providing coverage over the vision slits or blocks in it. This lid was adjustable, armored and rotatable and was to be fitted with either mechanical or hydraulic lifting means so that it could be elevated partially to provide vision, or fully to allow egress of the tank. In this way, the cupola lid functioned as a hatch which, when elevated, allowed the occupant of the vehicle to raise their head above the lip of the cupola for improved observations whilst providing protection from enemy fire or shrapnel from above. When in the raised position, the occupant could use a reverse periscope arrangement of mirrors on the inner face of the lid and outer face of the cupola to see outwards from behind armor.

‘Panzerturm für Panzerwagen, Tanks o. dgl.’ from German Patent DE736470(C) 1943 (left) and ‘Verdeckte Sichteinrichtung in verstellbaren Hauben von Panzerturmen in Panzerwagen o. dgl.’ from German Patent DE697874(C) 1940 (right).
Other military-related patents filed by Borgward included hydraulic steering for fully tracked vehicles (July 1941), a steering system for half-tracked vehicles (January 1940), and a resilient type of steel track with rubber bushings (August 1938). Further, he patented a dual-engine scheme for steering a fully tracked vehicle by varying drive from a single steering wheel (May 1938).

‘Lenkeinrichtung für Gleiskettenfahrzeuge’ from German Patent DE692794(C) 1940.

Conclusion

The majority of other patents from Borgward were related to cars, engines, bodywork etc. but it is this military vehicle design which is perhaps his most interesting work during the war. Borgward is better known for the Borgward B IV demolition vehicles which bear a superficial resemblance to this light tank but for this design and series of pattern Borgward, again and again, visited the same outline. He would modify it from an offset engine (at the back) in what could have been just an armored vehicle for one man, to a centrally mounted engine (at the back) allowing for a crew of two men.
Borgward considered many of the problems of a light tank, such as the ability to cross trenches and climb obstacles. Further, his design showed the use of torsion bar suspension with five independent wheels, which would certainly have provided excellent performance off-road considering that the predominant form of suspension for light tanks at this time was small coiled springs or leaf-springs on arms.

Borgward B IV demolition vehicle (left) with Goliath demolition device (right). Source: wiki
The problems with the design though are perhaps more obvious. It had no turret which limited fire to a narrow arc at the front and the vehicle lacked a roof (despite Borgward’s later design for a cupola cover), dangerously exposing the crew to shrapnel and enemy fire. With the first submission of this design at the end of 1937, it is surprising that Borgward submitted such an old-fashioned design for a vehicle. Perhaps the closest design to this one is not, in fact, German but Italian. The Carro Veloce 3 (CV.3) series of vehicles started life in 1929 and was in mass production several years before this design. With an encapsulated crew space, the CV.3 offered more protection for the crew than this design and with a double machine-gun mount, significantly more firepower too.
That Italian vehicle (CV.3) had seen service during the Spanish Civil War (1936-1939) alongside the German light tanks like the Panzer I against the Soviet-supplied T-26. The CV.3 was better protected than this Borgward design, the Panzer I had proven superior in fighting ability to the CV.3 as it had a turret, and the Soviet-supplied T-26 light tank had proven superior to both in terms of firepower. Yet despite these shortcomings, Borgward submitted a design for a vehicle worse than all three contemporaries in all areas apart from mobility, for which its advanced suspension would be an advantage. As such then, despite the suspension it is no surprise that the vehicle never entered production or use as improved and enclosed light tanks were already in development for the German Army. The Borgward light tank though is an important stepping stone in German tank evolution, as it marks one of the first light tank designs in Germany to use torsion bar suspension.

Specifications

Dimensions (L-W-H) 3.2 x ~2.5 x ~1.0 meter
Crew 2 (possible 1 in 1937)
Armament 1x Machine Gun
Armor N/A, est. 10 – 12mm
Total Production None

Sources

German Patent DE700020(C) ‘Lenkvorrichtung für Gleiskettenfahrzeuge mittels Lenkbremsen’ filed 27th October 1937. Accepted 14th November 1940. Published 11th December 1940.
German Patent DE720049(C) ‘Drehstababfederung für Lenker von unabhanging gefuhrten Radern von Kraftfahrzeugen’ filed 27th October 1937. Accepted 26th March 1942. Published 22nd April 1942.
German Patent DE719046(C) ‘Militarischen Zwecken dienendes Vollgleiskettenkraftfahrzeug, insbesondere Tank’ filed 27th October 1937. Accepted 5th March 1942. Published 27th March 1942.
German Patent DE718663(C) ‘Schutzchild und Sehschlitzanordung für Panzerwagen’ filed 2nd November 1937. Accepted 26th February 1942. Published 18th March 1942.
German Patent DE734712(C) ‘Schutzeinrichtung für die Gliesketten von Kampfwagen’ filed 4th November 1937. Accepted 25th March 1943. Published 22nd April 1943.
German Patent DE737703(C) ‘Laufband fur Kraftfahrzeuge’ filed 4th November 1937. Accepted 10th June 1943. Published 19th October 1943.
German Patent DE736470(C) ‘Panzerturm für Panzerwagen, Tanks o. dgl.’ filed 6th February 1938. Accepted 6th May 1943. Published 19th June 1943.
German Patent DE697874(C) ‘Verdeckte Sichteinrichtung in verstellbaren Hauben von Panzerturmen in Panzerwagen o. dgl.’ filed 6th February 1938. Accepted 26th September 1940. Published 25th October 1940.
German Patent DE687038(C) ‘Halbgleiskettenfahrzeug’ filed 22nd March 1938. Accepted 21st December 1939. Published 20th January 1940.
German Patent DE692794(C) ‘Lenkeinrichtung für Gleiskettenfahrzeuge’ filed 12th May 1938. Accepted 30th May 1940. Published 26th June 1940.
German Patent DE719862(C) ‘Gleiskette für Gleiskettenfarhzeuge’ filed 18th August 1938. Accepted 26th March 1942. Published 17th April 1942.
German Patent DE734330(C) ‘Lenkvorrichtung für Halbgleiskettenfahrzeuge’ filed 25th January 1940. Accepted 18th March 1943. Published 14th April 1943.
German Patent DE724797(C) ‘Gleiskettenantrieb für Gleiskettenfahrzeuge’ filed 22nd November 1940. Accepted 23rd July 1942. Published 5th September 1942.
German Patent DE734331(C) ‘Einrichtung zur Lenkung von Gleiskettenfahrzeuge’ filed 13th July 1941. Accepted 18th March 1943. Published 14th April 1943.

Categories
WW2 German prototypes

Panzer Sfl. Ic.

Nazi germany Nazi Germany (1940-42)
Tank Hunter – Two Test Vehicles Built

Ever since the late 1920s, the German Army (Heer) had recognised the need for self-propelled anti-tank guns. It was thought that by exploiting their mobility and low silhouette, these dedicated tank destroyers would be able to flank attacking enemy armor and take the momentum out of the offensive. However, this theory had failed to translate into practice by the time of the Second World War, as the need to prioritise funding for other technological developments meant that the dedicated tracked and half-tracked tank destroyer projects of the interwar years were unable to progress further than the prototype stage.
This shortcoming in mobile anti-tank firepower was exposed during the invasion of France in 1940 and the invasion of the Soviet Union in 1941. Confronted with more heavily armored tanks, such as the T-34, the standard 3.7 cm PaK 36 anti-tank gun was becoming increasingly obsolescent and there was a growing demand for heavier, more mobile anti-tank guns. In order to meet this need as quickly as possible, the Heer jettisoned the idea of a specialised self-propelled anti-tank gun built from the ground-up and instead authorised the conversion of obsolete or captured tank hulls to Panzerjäger (literally ‘tank hunter’), resulting in such ungainly machines as the Panzerjäger I and the 4.7 cm Pak (t) auf Pz.Kpfw.35R. At the same time, the development and fielding of the more powerful 5 cm Pak 38 and 7.5 cm PaK 40 towed anti-tank guns was accelerated.
The Panzer Selbstfahrlafette Ic (Pz.Sfl.Ic) was one of a multitude of developments to arise from this drive for improvised self-propelled anti-tank guns. However, unlike many of its contemporaries, it mounted the German-made 5 cm Pak 38 and used the hull of one of the latest and most advanced tank designs in the German inventory, the VK 9.01. Although this would appear to be a promising start to the project, the technological problems with the VK 9.01 chassis would ultimately compromise the viability of this development. The German word ‘Selbstfahrlafette’ translates to ‘self-propelled gun’ and is often abbreviated to Sfl. or (Sf).

Bad Genes: The VK 9.01 and its Defects

The VK 9.01 (Vollketten 9.01, meaning first design for a fully tracked vehicle in the 9 tonne class) had begun development in 1938 in response to a perceived need for a new, more mobile model of the Panzer II light tank. Heavily influenced by the ideas of Heinrich Ernst Kniepkamp, a talented engineer and head of the Waffen Prüfen 6 (Wa Prüf 6) agency of the German motorised vehicle procurement system, the VK 9.01 was designed to offer a revolutionary step forward in tank mobility.
To that end, it took advantage of several innovative automotive components then under development in Germany. These included a 150 hp Maybach HL 45 engine, an 8-speed preselective Maybach VG15319 transmission and various types of triple-stage steering units that would allow the tank to take turns at high speeds. A distinctive torsion bar suspension with five overlapping road wheels was attached to the hull, which allowed the tank to traverse rough ground at high speeds and provided a greater degree of manoeuvrability than contemporary designs. Taken together, these innovations meant that the VK 9.01 was not only relatively easy to drive, but that it could also reach speeds of up to 67 km/h (41.63 mph) on roads, an exceptionally high speed for fully-tracked vehicles of the time.
The vast improvements in mobility were complemented by the installation of a vertical stabiliser for the standard Panzer II 2 cm KwK. 38 main armament and the coaxial 7.92 mm M.G.34 machine gun that permitted it to fire more accurately on the move. Other than a new turret design and marginal increases in the armor protection, it remained similar to the existing model of the Panzer II in most other respects, maintaining the three-man crew of the original.
Initially, it was hoped that the first pre-production examples of the VK 9.01 would be able to enter production as soon as 1939, with mass production scheduled to commence in 1941. It would then subsequently replace the rest of the light tanks in the Heer’s inventory. These ambitious and grandiose plans would prove to be short-lived however, as the development process was constantly delayed by decisions to trial new steering units and transmissions. As a result, by the summer of 1940, none of the 75 0-Serie (pre-production) VK 9.01 then under contract had been produced and work had even started on a new variant with a more powerful engine and marginally thicker armor known as the VK 9.03.
In the end, the protracted development process and the need to rationalise German tank production meant that the VK 9.01 never fulfilled its destiny. Although 55 of the 0-Serie hulls with a bewildering variety of transmissions and steering systems were completed between 1941 and 1942, mass production never occurred as, by that time, there was a more pressing demand for heavier armored vehicles such as the Panther. Worse still, the VK 9.01 proved to be an unreliable machine during testing precisely because of the new automotive components that ironically more often that not broke down and crippled the machine. Consequently, the VK 9.01 never saw any notable uses during the war and is now a largely forgotten episode in the saga of German Second World War tank development.
Although the officials of Inspektorat 6 (the body nominally responsible for drawing up requirements for armored vehicles) could not have foreseen the ultimate demise of this project when they initiated the development of a tank destroyer based on the VK 9.01 on 5 July 1940, these faulty genes were to determine the fate of this project too.

Small but Deadly: The Pz.Sfl.Ic Design

Following the July 1940 directive from Inspektorat 6 to develop a light Panzerjäger (tank hunter) able to keep pace with Panzer Divisions and Motorised Infantry Divisions, Wa Prüf 6 awarded contracts to the Berlin-based company Rheinmetall-Borsig to draw up designs for a 5 cm Pak mounted on a VK 9.01 hull. According to Yuri Pasholok, Rheinmetall-Borsig then allocated this work to Alkett, another firm based in Berlin. While this could make sense given Alkett’s involvement in other armored vehicle projects, it is not mentioned in any other publications. Indeed, Thomas L. Jentz and Hilary L. Doyle, having looked at original German wartime documents, state in their book Panzer Tracts No.7-1 that the superstructure conversion work was completed by Rheinmetall-Borsig on the M.A.N. built hull. They do not make any reference to this work being subcontracted out.
Regardless of the exact division of the labour, this presents a problem for those studying this armored vehicle today, as surviving primary source material concerning the development of armored fighting vehicles during this period at Rheinmetall-Borsig has mostly been lost. Unfortunately, this means that there are many unanswered questions relating to the history of this project and the technical details of this conversion.
One such problem is the designation of the machine itself. It was known as the Panzer Selbstfahrlafette Ic (English: Armored Self-propelled Carriage Ic). While Panzer Selbstfahrlafette is a common enough element in the designations of armored vehicles converted by the Germans into self-propelled guns, the Ic aspect is unusual. Some other German tank destroyers received similar combinations of Roman numerals followed by alphabetical suffixes, such as the 10 cm Kanone Panzer Selbstfahrlafette IVa (better known as ‘Dicker Max’). Given that there was a Panzer Selbstfahrlafette Ia based on a converted VK 3.02 munitions carrier, it is likely that the ‘c’ means that this was the third design in a series of 5 cm self-propelled anti-tank guns, but it is not possible to be sure.

A factory-fresh Pz.Sfl.Ic. This provides a clear view of the VK 9.01 chassis, the two-tiered superstructure and the 5 cm Kanone L/60 gun. Note the appliqué armor fitted to the side of the hull, which is visible next to the two shock absorbers. Ancillary equipment for the gun such as the cleaning rods is stowed on the side of the lower tier of the superstructure and a canvas cover strapped onto the roof shields the crew from the elements. Photo: warspot.ru
Nevertheless, what can be gleaned from the few fragments of surviving information and photographs is that the Pz.Sfl.Ic involved the mounting of a fixed open-topped superstructure onto a standard VK 9.01 hull. It is unclear whether the VK 9.01 hulls used to create the Pz.Sfl.Ic were part of the 55 0-Serie VK 9.01 chassis completed in 1941 and 1942 or if they were extra hulls produced especially for this purpose. Nevertheless, they appear to have maintained the same suspension and general layout of the base tank. They carried the same level of armor protection, consisting of 30 mm at the front, 14.5 mm at the sides which was bolstered by an additional 5 mm of appliqué armor, and 14.5 mm at the rear.
Mounted in place of the turret was a two-tiered armored superstructure. On the bottom tier, this contained a driver’s visor of the same type fitted to the VK 9.01 at the front, as well as two elongated visors at the front right and left hand sides. Gun cleaning rods were also stowed on the left-hand side of this lower tier of the superstructure. A slightly shorter and narrower tier of the superstructure containing the 5 cm gun and its mounting surmounted this lower segment. It is unclear whether this top section of the superstructure could rotate like a turret, but there is no indication in documents or photographs that this was the case. Hence, it is likely that elevation and a limited degree of traverse to either side was provided by the gun mount, as with other comparable designs such as the Marder II and Marder III.
The main gun selected for the Pz.Sfl.Ic was the 5 cm Kanone L/60, a derivative of the 5 cm Pak 38 towed anti-tank gun that had been under development at Rheinmetall Borsig since 1938. This version of the gun had modifications to the breech, carriage and recoil mechanisms to make it more suitable for use within the confines of an armored vehicle.
According to one German technical document issued during the war, the 5 cm Pak 38 could penetrate 69 mm of armor at 100 m when firing the 5 cm Panzergranate (Pzgr.) 39 armor piercing capped (APC) round, which was increased to 130 mm with the 5 cm Pzgr. 40 armor piercing composite rigid (APCR) rounds. At distances of 1,000 m, the penetration decreased to 48 mm and 38 mm respectively. However, it is important to note that stocks of the 5 cm Pzgr. 40 APCR round were limited due to its tungsten core. Tungsten was a valuable material that was in short supply in wartime Germany and required for many other industrial purposes. It could therefore not be squandered on producing vast numbers of anti-tank rounds meaning that tank and anti-tank gun crews were generally issued only a few of these rounds at a time for use in the most threatening situations.

An excerpt from an original German document outlining the penetration of the 5 cm Pak 38. Whilst the 5 cm Pak 38 was adequate for dealing with most enemy tanks that might have been encountered in 1942, the Heer was already seeking more powerful anti-tank guns to deal with anticipated future threats. It is important to note that each military had its own procedures for measuring and testing penetration which could lead to different results for the same gun and projectile. Source: valka.cz
Compared to the VK 9.01 tank, the Pz.Sfl.Ic accommodated an extra crew member for a total complement of four men. Presumably, this included a driver and radio operator seated in the front left and front right of the hull respectively, plus two men in the top part of the superstructure to load and fire the gun, one of whom would have been the vehicle commander.
Despite these significant changes to the VK 9.01, its performance (at least on paper) does not appear to have been adversely affected. The 150 hp Maybach HL 45 engine was still capable of propelling the vehicle to a maximum speed of nearly 70 km/h and the weight remained at 10.5 tonnes, the same as the standard VK 9.01.
Even so, due to the scarcity of documentation concerning this vehicle, there is no way to evaluate how well these design specifications translated into practice. When the 0-Serie VK 9.01 tanks were evaluated at the Berka proving ground sometime in 1941 or 1942, they fared miserably. Most of the tanks succumbed to breakdowns after covering relatively short distances, and problems with getting the automotive components to work reliably proved to be an insurmountable challenge for the engineers.
Presumably, such problems would also have afflicted the Pz.Sfl.Ic had it ever entered mass production, but in the absence of test reports, one can only speculate.


Illustration of the 5 cm PaK 38 auf Pz.Kpfw. II Sonderfahrgestell 901 (Panzer Selbstfahrlafette Ic), produced by Alexe Pavel, funded by our Patreon Campaign.

Big Plans for a Small Tank Destroyer: Pz.Sfl.Ic Production

On 30 May 1941, almost one year after Rheinmetall Borsig had been contracted to begin designing the Pz.Sfl.Ic, the Heer issued a document called the Heeres Panzerprogramm 41 (Army Tank Program 41). An exercise in long-range planning, this document outlined the production quantities of all vehicles necessary to outfit a total of 20 new Panzer Divisions and 10 new Motorised Infantry Divisions by 1945. By this time, the successor to the VK 9.01, the VK 9.03, was the preferred choice of new model light tank for the Heer. As such, the Panzerprogramm 41 envisaged the production of almost 10,000 of these new light tanks.
In addition to the standard tanks, the planners behind the Panzerprogramm 41 also envisaged an entire family of armored vehicles based upon the VK 9.03. Sources differ on the exact number, but this would have included between 1,028 and 2,028 tank destroyers armed with a 5 cm anti-tank gun referred to as l.Pz.Jäger (Pz.Sfl.5 cm) auf VK903 Fgst. (Light Tank Destroyer on VK 9.03 chassis). As there were only minor differences between the VK 9.01 and VK 9.03, it is likely that such a tank destroyer would have closely resembled the Pz.Sfl.Ic.
However, this document was more aspirational than it was realistic. It was not based on any sober assessment of German economic capabilities, nor did it offer precise guidelines on how such astronomical (for the standards of mid-1941 German industry) production figures were to be achieved. At the time the document was issued, the VK 9.03 was still on paper and fewer than 15 of the 0-Serie VK 9.01 had left the production line, which raises several questions as to whether such plans as laid out in the Panzerprogramm 41 would have been feasible.
In the end, the VK 9.03 never entered production and only two trial examples of the Pz.Sfl.Ic based on VK 9.01 hulls were ever made. According to a report issued in July 1941, these were scheduled for completion in September 1941. There is no way of knowing whether production kept to this schedule, but in any case, the two machines were completed by March 1942 at the latest.

Trials on the Eastern Front: The Pz.Sfl.Ic in Combat

Unlike many experimental vehicles that were typically constructed out of unarmored mild steel, the two Pz.Sfl.Ics were made from armor plate. This meant that they were suitable for deployment in combat and the Heer did not waste this opportunity.

All two of the Pz.Sfl.Ic in service with the third platoon of Panzer-Jäger Company 601 (later renamed as the 3rd Company of Panzer-Jäger battalion (Sfl.) 559) as it travels through the small town of Kloster Zinna in Brandenburg. A Kleinepanzerbefehlswagen I (a small command tank based on the Panzer I hull) leads the convoy, while at least four of the 8.8 cm Sfl. half-tracks bring up the rear. The relatively small size and low silhouette of these tank destroyers can be appreciated by comparing them to the humongous half-tracks and the young boys walking in the middle of the road. Note that the frontal plate of the Pz.Sfl.Ic superstructure only has a single visor for the driver, perhaps suggesting that there was not a separate radio operator (who would normally have his own visor) and a three-man crew instead of four. Source: valka.cz
On 10 March 1942, the two Pz.Sfl.Ic vehicles were assigned to the 3rd platoon of Panzer-Jäger Company 601 to replace some of the 8.8 cm Sfl. (8.8 cm Flak 36 mounted on Sd.Kfz.8 half-tracks) that had been lost in combat on the Eastern Front. Later renamed as the 3rd Company of Panzer-Jäger battalion (Sfl.) 559 on 21 April 1942, this unit operated under the 2nd Army, itself part of Army Group South.
Unfortunately, little else is known about the service of the Pz.Sfl.Ic on the Eastern Front. There are no known surviving trials reports detailing its performance in combat or discussing any issues with the design. A few surviving photographs prove that they did indeed make it to the front, and a strength report dated 20 August 1941 states that the 3rd Company of Panzer-Jäger battalion (Sfl.) 559 still had two Pz.Sfl.Ic at that time, one of which was operational. However, the Pz.Sfl.Ic simply vanishes from the paperwork after this point, with no mention of the ultimate fate of these two vehicles.
This suggests that unless they were sent back to Germany for some reason, the guns likely perished by the end of 1942. At the time the Pz.Sfl.Ic joined the 3rd Company of Panzer-Jäger battalion (Sfl.) 559, Army Group South had been split into two groups for the assault on Stalingrad and the Caucasus oil fields. As part of Army Group B, the 2nd Army protected the northern flank of the 6th Army as it fought its way into Stalingrad, until it was decimated by the Soviet winter offensive in late 1942 and early 1943.
It is unlikely that the Pz.Sfl.Ic would have survived this maelstrom, especially if the technological foibles that plagued the VK 9.01 had also afflicted this machine. The maintenance nightmare involved in keeping these fickle vehicles running would have been compounded yet further by the bewildering menagerie of different vehicles operated by Panzer-Jäger battalion (Sfl.) 559, which also included Panzer Selbstfahrlafette 1 für 7.62 cm Pak 36 auf Fahrgestell Panzerkampfwagen II Ausf. D and 8.8 cm Sfl. halftracks.

A Pz.Sfl.Ic entrained with a group of Panzer IIIs. Few details of this vehicle are visible on this photograph, other than the prominent Balkenkreuz and the fact that it is missing one of its outer road wheels. The exact location of this train and its intended destination are unknown, though this photo once again shows that the Pz.Sfl.Ic did make it to the front. Source: valka.cz

Too Little, Too Late

The fate of the Pz.Sfl.Ic was tied to that of its host, the VK 9.01. Once work on the deeply flawed and troublesome VK 9.01 and VK 9.03 tanks was abruptly terminated in March 1942, any hopes that the Pz.Sfl.Ic would be mass produced were dashed, as the entire rationale behind such projects was to save time and funds by converting readily available hulls.
Yet even if by some miracle the VK 9 series had entered mass production as the new model of Panzer II, the Pz.Sfl.Ic would still have had a precarious future. By the time the first two trials machines had been issued in March 1942, the Heer was already looking to guns of a calibre greater than 5 cm to counter the ever increasing armor of enemy tanks. Consequently, conversions involving captured Czechoslovakian 4.7 cm and 5 cm Pak 38 guns were superseded by those equipped with captured Soviet 7.62 cm guns or the new 7.5 cm Pak 40, resulting in the well-known Marder (Marten) series among others. This prevailing trend suggests that the Pz.Sfl.Ic would not have remained in production for long.
Although there were paper projects to mount the 7.5 cm gun on the VK 9 series (and a photo of one such conversion suggests it even seems to have been carried out), the fact that the VK 9.01 and VK 9.03 never entered mass production meant that such ideas would never have been able to enter widespread service.
Ultimately then, the Pz.Sfl.Ic was a non-starter. The failure of the VK 9 initiative undercut the reason for its existence and the gun it was equipped with was already starting to be outclassed due to the frenetic pace of Second World War tank development. Apart from a few photographs and a smattering of documents, nothing of the Pz.Sfl.Ic project survives to this day, but it remains a curious example of the German propensity to experiment with self-propelled gun conversions throughout the war.

A rare glimpse at the rear of the Pz.Sfl.Ic. Taken in the summer or autumn of 1942, this photograph is proof that the Pz.Sfl.Ic did indeed make it to the front. Like all other German armored vehicles in use on the front line, it has a Balkenkreuz painted on the hull side for identification purposes. The wrecked Soviet fighter in the foreground suggests that this may be in the vicinity of an airfield. Source: warspot.ru

Specifications

Dimensions (L-W-H, based on VK 9.03) 4.24 m x 2.39 m x 2.05 m
Weight 10.5 tonnes
Crew 4
Propulsion Water-cooled gasoline Maybach HL 45 motor producing 150 HP at 3800 rpm
VG 15319, or OG 20417, or SMG 50
Transmission LGR 15319 or LGL 15319 Triple radius differential steering unit
Speed (road) 67 km/h (regulated to 65 km/h)
Armament 5 cm Kanone L/60
Armor 30 mm hull front
14.5 mm + 5 mm appliqué hull side
14.5 mm hull rear
Superstructure armor unknown
Total production 2

Bibliographical Comment

The most accurate source on the Pz.Sfl.Ic is Panzer Tracts 7-1 written by renowned German Second World War AFV historians Thomas Jentz and Hilary Doyle. However, only a single page of this book is devoted to the Pz.Sfl.Ic, reflecting the dearth of primary source material for this vehicle.
An online article originally written in Russian by Yuri Pasholok and available in English translation provides a decent summary of the Pz.Sfl.Ic and helps to place it in the wider context of the development of the VK 9 series of projects.
Asides from a few photographs showing the Pz.Sfl.Ic on deployment (one of which was published in Autumn Gale), little else has emerged on this elusive machine.
Note that in the popular online game War Thunder, the VK 9.03 is mislabelled as the Pz.Sfl.Ic. The actual history of the VK 9.03 can be found in another Tanks Encyclopedia article.

Sources

Didden, J., and Swarts, M., Autumn Gale/Herbst Sturm: Kampfgruppe Chill, schwere Heeres Panzerjäger Abteilung 559 and the German Recovery in the Autumn of 1944 (Drunen: De Zwaardvisch, 2013).
Doyle, H.L., and Jentz, T.L., Panzer Tracts No.2-2 Panzerkampfwagen II Ausf. G, H, J, L, and M: Development and Production from 1938 to 1943 (Maryland: Panzer Tracts, 2007).
Doyle, H.L., and Jentz, T.L., Panzer Tracts No.20-2 Paper Panzers: Aufklaerungs-, Beobachtungs-, and Flak Panzer (Reconnaissance, Observation, and Anti-Aircraft) (Maryland, Panzer Tracts, 2002).
Doyle, H.L., and Jentz, T.L., Panzer Tracts No.7-1 Panzerjaeger (3.7 cm Tak to Pz.Sfl.Ic): Development and Employment from 1927 to 1941 (Maryland: Panzer Tracts, 2004).
Spielberger, W.J., Der Panzer-Kampfwagen I und II und ihre Abarten: Einschließlich der Panzerentwicklungen der Reichswehr (Stuttgart: Motorbuch Verlag, 1974). Translated into English as Panzer I and II and their Variants: From Reichswehr to Wehrmacht (Pennsylvania: Schiffer Publishing US, 2007).
Pasholok, Y., ‘Pz.Kpfw.II Ausf. G: The Fruit of Unending Labour’. Read HERE (Russian), English version HERE.

Categories
WW2 German prototypes

Panzer II Ausf. H & Ausf. M (VK9.03)

Nazi Germany (1940-42)
Light/Reconnaissance Tank – At Least One Prototype Hull Completed

At the start of the Second World War, the Panzer I and Panzer II light tanks far outnumbered any of the other tanks in the German inventory. Lightly armed and armored, these fragile machines were already nearing obsolescence by the time Poland was invaded in September 1939. Conscious of the fact that these tanks required modernisation if they were to remain viable into the future, in the late 1930s, German engineers embarked upon a plethora of projects to improve the Panzer I and Panzer II. One of the first attempts was the VK 9.01, a project begun in 1938 to enhance the mobility of the Panzer II by introducing technologically advanced automotive components and a new suspension into the design. Conceived in July 1940, the VK 9.03 was the next major iteration of this series, featuring marginally thicker armor and a more powerful engine than its predecessor. Despite these limited improvements, the VK 9.03 came close to gaining approval for mass production as both the Panzer II neuer Art (new model) Ausf. H and the Panzer II Ausf. M.
Like the rest of the VK 9 family of tanks, the design of the VK 9.03 was closely intertwined with the tank design philosophy of Heinrich Ernst Kniepkamp, an influential engineer and a leading figure in the Heeres Waffenamt (Army Ordnance Department). Following Kniepkamp’s belief that speed and firepower were of paramount importance in tank design, the VK 9 series was designed to incorporate the latest automotive technology developed by German engineers, such as new transmissions and steering systems. In theory, this sophisticated technology would create a more mobile platform that was easier for its crews to operate. In reality, the immature, temperamental automotive components proved to be an unending nightmare for the tanks’ crews.
Yet even before the technological problems became apparent, the VK 9.03 lived a precarious existence. Right from the moment of its inception in July 1940, it was merely one project among a litany of contradictory and seemingly mutually exclusive designs aimed at creating a new model Panzer II. At the same time as the VK 9.03 was struggling to get off the drawing board, work was ongoing on several more promising new model Panzer II projects, such as the VK 13 series with its more spacious interior and four-man crew. Moreover, operational experience in the Polish and French campaigns had raised questions over the utility of such lightly armed and armored tanks outside the sphere of reconnaissance. In light of these realities, it would appear miraculous that the VK 9.03 project was even approved, let alone considered for mass production, were it not for the muddled and irrational state of German tank procurement; a circumstance that allowed projects such as the VK 9.03 to gain their own momentum irrespective of wider economic considerations and the needs of the troops in the field.

Castles in the Sky: The Transformation of German Tank Procurement

The early war Nazi economy was beset by problems and inefficiencies caused by a contradictory ‘guns and butter’ policy, overlapping administrative jurisdictions, and the mismanagement of resources. These underlying structural issues that afflicted the Nazi state were reflected in the disorganized nature of the German tank procurement system of 1940. It was in this context that the visionary and talented engineer Heinrich Ernst Kniepkamp came to prominence.
As the chief of Waffen Prüfen 6 (Wa Prüf 6), a subdivision of the Heeres Waffenamt (Army Ordnance Department) responsible for overseeing the design of new tanks and other motorized vehicles, Kniepkamp was involved in nearly all of the major German AFV projects of the Second World War. Under his stewardship, this department of engineers came to usurp the authority of Inspektorat 6 (In 6), the Army’s procurement office for armored vehicles and other such similar equipment. Whereas In 6 had previously determined which kinds of tanks the Heer needed and Wa Prüf 6 had merely translated these stipulations into engineering specifications, by the late 1930s, Wa Prüf 6 began to assume greater control over what types of tanks should be produced. This outsized influence resulted in a situation where tanks were designed less in accordance with Army requirements than with the whims and wishes of the engineers in Wa Prüf 6 and the design firms. Consequently, the doors were opened to a smorgasbord of projects, many of which were technologically sophisticated, yet also in many cases impractical, unnecessary, and unwanted.
In a typical example of this design frenzy, by the end of 1939, the design firm Maschinenfabrik Augsburg-Nürnberg (M.A.N.) was working on three separate projects to improve the Panzer II: the VK 9.01 (the future Panzer II Ausf. G), the VK 13.01 (which later evolved into the VK 13.03, more commonly known as the Panzer II Ausf. L ‘Luchs’), and the more heavily armored VK 16.01 (later adopted as the Ausf. J). This is reflective of the lack of oversight and direction in German tank procurement at the time; German engineers could not decide whether an improved Panzer II should be more mobile or if it should have greater armored protection, nor could they figure out whether it should have a three-man or four-man crew. Rather than decide on a specific approach, they simply squandered resources on pursuing all three, despite the inherent overlaps and contradictions among these designs.
Although one might expect that the onset of war would have put paid to this free-for-all in favor of a more rationalized production schedule, the chaos was, if anything, exacerbated. The VK 9.03 emerged from this increasingly complex web of intersecting designs and the competing procurement initiatives engendered by this situation.
Note to the reader: Most of the projects to improve the Panzer II received a designation in the VK index. Created by Kniepkamp, this index categorised the configuration of the vehicle (VK/HK – Vollketten/Halbketten – Full-tracked/Half-tracked), its projected weight, and its position in the development cycle. So VK 9.03 referred to the third design for a (projected) nine tonne fully-tracked armored vehicle. For the purposes of consistency and clarity, I have elected to use the format VK X.0X or VK XX.0X when referring to VK index numbers in this article. Publications and period documents refer to VK designations in a multitude of different ways, thus VK 901 or V.K.901 can both be considered ‘correct’ alternatives to VK 9.01.

Heinrich Ernst Kniepkamp in uniform. After receiving responsibility for overseeing the creation of new tank designs in 1936, Kniepkamp became one of the most influential figures in German Second World War armored fighting vehicle development. Under Kniepkamp’s guidance, German engineers initiated the designs for several famous tanks, including the Panther, the Tigers, and the various E-series projects. Although nowhere near as well-known as their contemporaries, the VK 9.01 and VK 9.03 epitomized Kniepkamp’s conception of the ideal light tank. Source: Wikimedia Commons

More of the Same: The VK 9.03 Design

In June 1940, not long after the Heeres Waffenamt had delivered the disappointing news to In 6 that mass production of the VK 9.01 would not be possible until November 1941, In 6 instructed Wa Prüf 6 to commence work on the VK 9.03. With a projected weight of 10.5 tonnes, this new design was to sport thicker armor and a more powerful engine than the VK 9.01. However, in nearly all other respects, the characteristics and components remained exactly the same as its predecessor to such an extent that it is quicker to list the differences than it is the similarities.
Even though improved armor protection was stipulated as one of the primary goals of this project, the slight weight expansion did not permit a vast increase in armor thicknesses over the VK 9.01. In fact, only the sides of the hull and the rear were to be increased from 14.5 mm to 20 mm, whilst the rest of the armor remained the same with a maximum of 30 mm on the front of the hull. Although the increase in the thickness of the hull sides and rear may have rendered the VK 9.03 slightly more resistant to anti-tank rifles, which had knocked-out many Panzer IIs in Poland, this was hardly a massive increase that would drastically increase the survivability of this tank of the battlefield.
The other most significant change implemented in the VK 9.03 was the installation of a more powerful Maybach HL 66 P engine. Originally developed in 1938 for the HK (meaning Halbketten – ‘Half-tracked’) 9.01 half-track design, Maybach had manufactured five of these engines by the end of 1940 followed by 14 more in 1941. Rated at 200 hp, this engine was calculated to be capable of providing sufficient power to allow the VK 9.03 to attain a maximum road speed of 65 km/h, an impressive speed for a tracked vehicle of that time period. Given that the lighter VK 9.01 could reach 67 km/h with its less powerful 150 hp HL 45 engine, this did not really represent an improvement; instead, it merely ensured that the VK 9.03 maintained the mobility of its predecessor.
Indeed, on 22 June 1940, engineers attempted to derive the automotive characteristics of the VK 9.03 by calculating the effects of installing a Maybach HL 66 engine and a strengthened VG 15319 transmission able to withstand higher torque into a heavier but otherwise unchanged VK 9.01 hull. Whereas in these initial studies the VK 9.01 suspension was not altered in any way, the Kgs. 61/300/10 tracks of the VK 9.01 were eventually exchanged for wider Kgs. 63/360/90 tracks, thereby increasing the wheelbase of the vehicle from 2.00 to 2.08 m.
Aside from these changed characteristics, the VK 9.03 remained virtually identical to the VK 9.01, retaining the three-man crew (comprising a commander/gunner, radio operator, and driver), and the 2 cm Kw.K. 38 and M.G.34 (Pz.) armament. Due to the disparity in the number of surviving documents between M.A.N. (the designer of the hull) and Daimler-Benz (designer of the turret and superstructure), details concerning the initial design of the turret and superstructure for the VK 9.03 are scant. However, given the extensive similarities between the VK 9.01 and VK 9.03, it is likely that the turret and superstructure would have resembled that fitted to the VK 9.01, but this is merely speculation.
Even though the VK 9.03 does not appear to have offered any substantial enhancements to the already delayed VK 9.01, Wa Prüf 6 had awarded contracts to M.A.N. to design and build five Versuchs-Fahrgestell (trial chassis) and Daimler-Benz to design the Aufbau (turrets and superstructures) by the end of 1940.
Ordered already in June 1940, the first of these VK 9.03 Versuchs-Fahrgestell was to be equipped with the Maybach VG 20417 transmission and the LG 45 L steering unit, the latter of which had already been proposed for the aborted VK 9.02. Considered to be at the cutting edge of German automotive technology for the time, these components were specifically selected for the VK 9 series in order to deliver the excellent mobility and ease of operation deemed so essential by Kniepkamp. In a cruel twist of irony unbeknownst to the engineers at the time, these ill-fated immature components were to prove a constant source of breakdowns when they were trialed in the VK 9.01.

A factory-fresh 0-Serie VK 9.01 (adopted as the Panzer II Ausf. G) photographed by Wa Prüf 6 in 1941. The VK 9.03 shared many of the features introduced with this design, including the stabilized armament and the torsion bar suspension with overlapping road wheels. Although it is unclear whether or not the VK 9.03 was originally intended to use the same superstructure and turret as the VK 9.01, it is likely that it would have looked similar given the VK 9.03’s overall resemblance to the VK 9.01 design. Source: warspot.ru

The Great Expectations: Plans for Mass Production

The numerous similarities between the design of the VK 9.01 and VK 9.03 were paralleled by the equally ambitious plans for mass production. Formed before the technologically advanced automotive components used by the VK 9.01 and VK 9.03 had even undergone thorough testing, these lofty schemes envisioned contracts for thousands of tanks that would re-equip the combat reconnaissance units in the Panzer Divisions and the Motorised Infantry Divisions.
As soon as 8 January 1941, by which point the majority of the design drawings for the VK 9.03 hull had been completed, the Waffenamt awarded a contract to M.A.N. for the production of 500 VK 9.03 hulls. Presumably, Daimler-Benz, which had been tasked with designing the Aufbau on 23 September 1940, also received a production contract for 500 turrets and superstructures to be mated to these hulls. This contract suggests that the VK 9.03 had displaced the VK 9.01 as the primary candidate for a mass-produced new model of Panzer II, as whilst mass production of the VK 9.01 was frequently discussed, a series production contract beyond the 75 0-Series trial hulls never materialized.
Regardless of these optimistic plans, it is important to recognize that by the time this contract had been awarded, M.A.N. was only just on the cusp of completing the first VK 9.01 0-Serie hulls that had been ordered over a year ago. This vast chasm between the aspirations for the VK 9 project and its tangible results were exposed in an almost comical segment of a meeting concerning the status of developmental vehicles held on 23 May 1941 between M.A.N staff and General Radlmeier, a representative of the Reichsministerium für Bewaffnung und Munition (Reich Ministry of Armaments and Munitions). Perhaps understandably, Radlmeier had visited M.A.N. with the impression that the VK 9.03 was ready to progress to series production; after all, according to information available at the Ministry, VK 9.03 mass production was to begin in January 1942. It fell to M.A.N. staff to explain to a reportedly ‘very astonished’ Radlmeier that the production of the first five Versuchs-Fahrgestell had only just started, and that M.A.N. had scheduled the production of the first series production VK 9.03 for April 1942. In a statement that did not bode well for the innovative and unproven VK 9.03, this segment of the report concluded with Radlmeier’s ominous pronouncement that future Panzer production would focus on mass production of mature tank designs on automobile-style assembly lines.
Yet despite this telling indication that the pressures of wartime economic management were starting to militate against novel and technologically complex designs such as the VK 9.03, this new model of Panzer II remained firmly entrenched in the Heer’s long-range planning. On 30 May 1941, a document known as the Schwerpunktprogramm ( Priority Program – Schwerpunkt being a German term, often used in relation to ‘Blitzkrieg’, that refers to the focal point of a particular effort) outlined the production quantities of all vehicles necessary to fulfil the requirements of the Heeres Panzerprogramm 41 (Army Tank Program 1941). In order to outfit a total of 20 new Panzer Divisions and 10 new Motorised Infantry Divisions, the Waffenamt calculated that the Heer needed 2,592 VK 9.03 tanks for combat reconnaissance in Panzer units, as well as another 8,111 VK 9.03 armored reconnaissance vehicles for headquarters, infantry, motorized infantry, Panzer, pioneer, reconnaissance, and tank-hunter units. Moreover, 1,483 VK 9.03 tanks were to be used for commanding tank-hunter units and for artillery observation in artillery units, not to mention 1,028 chassis for tank destroyers mounting a 5 cm anti-tank gun and 360 chassis for self-propelled 15 cm s.I.G. 33 guns.
Such colossal demands necessitated a correspondingly prodigious production output. To meet these targets, the document declared that 300 Panzer II would need to be completed by April 1942, 1,380 by 1 April 1943, 4,980, by 1 April 1944, and 13,980 by 1 April 1945. In a concession to the inconveniences of reality, it was accepted that production of the standard Panzer II (the Ausf. F) would have to continue until VK 9.03 production could begin in earnest, whenever that might be. Unfortunately for these assiduous planners, such targets, if they were ever obtainable in the first place, would require a degree of economic rationalization that, at least in the case of Panzer II development, was sorely lacking among both industry and the Waffenamt.
Rather than prioritize effort on perfecting a single design that would have been suitable for the kind of mass production on assembly lines desired by economists, the Waffenamt continued to pursue multiple projects, without deciding on a clear trajectory for future production. Thus, by August 1941, the contract for 500 VK 9.03 had fragmented into a contract for 250 VK 9.03 and 250 VK 13.03, another even heavier Panzer II variant that was intended to use the same automotive technology as the VK 9 series but would mount a more spacious two-man turret. A sixth VK 9.03 Versuchs-Fahrgestell was also ordered, with the first one that had been ordered back in June 1940 expected to be completed by September of 1941.
In the space of just a few months, the VK 9.03 project was to splinter still further, as more new additions were proposed and several alterations introduced. Consequently, the yawning gap that separated German tank design from the needs of troops on the battlefield and the imperative of economic rationalization became a chasm.

A photo of the Maybach HL 66 P engine from a technical manual published in May 1942. Capable of producing 200 hp at 3,000 rpm, this engine was proposed for installation in the VK 9.03. The same engine was later employed by the VK 13.03, an alternative new model of Panzer II also developed by M.A.N. Source: valka.cz

The Fragmentation of the VK 9.03 Project

Back in May 1940, M.A.N. and Waffenamt officials had reassured one another that mass production of the Panzer II neuer Art, then in the guise of the VK 9.01, would be underway by November 1941. However, as November approached, the prospect of mass production was not even on the horizon, let alone the foreseeable future. Although a total of 15 of the 75 VK 9.01 0-Serie chassis had been delivered to the Heer by the end of August 1941, their performance in trials held at the Berka testing ground was far from encouraging, with numerous breakdowns and teething troubles afflicting the new automotive components. In any case, the VK 9.01 had already been superseded as the candidate for mass production by the VK 9.03, which was itself also facing competition from the new VK 13.03 design.
The precarious future of the VK 9.03 was compounded still further by the sudden introduction of new members of the VK 9 family. Following another visit from General Radlmeier on 15 August 1941, M.A.N. reported that he was ‘especially interested’ in new tank designs, namely the VK 9.04 and VK 9.05. According to the report, these designs were not to be produced in their own separate batches, but instead, as part of the 250 VK 9.03 ordered on 1 August 1941. Just as the VK 9.01 had been displaced by the VK 9.03, the VK 9.03 also faced being made redundant by new designs in its own family of armored vehicles.
Unfortunately, very little is known about the VK 9.04 and VK 9.05, other than the fact that they existed. Asides from the aforementioned report of Radlmeier’s visit, the only other snippet of information concerning the VK 9.05 comes from a report on engine development submitted by Maybach on 31 March 1942. In this report, the VK 9.05 is mentioned as having a 400 hp Maybach HL 100 petrol engine and a Lenkkupplung steering unit. Given the absence of any other details, it is highly likely that the VK 9.04 and VK 9.05 remained nothing more than conceptual designs.
If these issues with technology, production, and competing designs did not place the VK 9.03 in sufficient jeopardy, the nature of the war on the Eastern Front was also starting to call into question the validity of expending such a vast amount of effort and resources on a light tank. The experience of fighting against Soviet tanks catalyzed plans to upgun the existing Panzer III and Panzer IV medium tanks, and as a result, more emphasis came to be placed on creating new designs with more firepower and greater armored protection. As one of Germany’s primary producers of armored vehicles, trucks and heavy industrial equipment, M.A.N. was forced to focus its efforts on sustaining production of the Panzer III and later the famous Panther. This changing wartime context, therefore, left little room for mass production of a vulnerable, immature, unproven and complex light tank such as the VK 9.03.
The implications of this situation were made apparent in a report by the assembly department of M.A.N. dated 18 August 1941. According to this report, the requirement to produce 20 Panzer III and 50 VK 9.03 per month would necessitate the expansion of the assembly hall in order to accommodate 125 new machine tools, as well as a new department for the working of gear wheels. This latter provision was particularly important, as the finishing of gear wheels was one of the major bottlenecks of Panzer production at the M.A.N. assembly hall. Since there had been delays in the arrival of gear finishing facilities at M.A.N., the factory was compelled to sub-contract the work to other factories such as Zahnräderfabriken Augsburg, and would be unable to increase its own output over the next two years. Since the VK 9.03 would have needed three times as many gears as the Panzer III, this setup was likely to seriously impede mass production of the VK 9.03.
The report goes on to note that the equipment used to machine holes in the hull sides for torsion bar suspensions would need to be reworked for the VK 9.03, further delaying the startup of mass-production. This report, which provides an interesting glimpse into the somewhat mundane factors that influenced tank production, did not bode well for the VK 9.03. Faced with these hurdles to overcome and the need to increase production of arguably more relevant designs, it must have begged the question: was the VK 9.03 worth the effort?
These difficult questions were of little concern to those involved with the design process, who continued to run rampant proposing new additions to the VK 9.03. One such example of this was the idea to replace the 2 cm Kw.K. 38 main armament of the VK 9.03 with a more powerful 2.8 cm self-loading cannon derived from the 2.8 cm sPzB 41 heavy anti-tank rifle. Known by several names, including Geschütz 8202, Wg 8202 SLMG, 2.8 cm Kw.K. 41, and then, after delays with its production, 2.8 cm Kw.K. 42, this weapon was fitted with a Mauser-designed gas pressure loader. It was calculated to be capable of firing 15-20 aimed rounds per minute and was intended to be able to penetrate 60 mm of armor at 30 degrees from a range of 100 meters when firing the 2.8 cm Pzgr. 41 round.
Reflecting the breakdown of the German procurement system, it was Hitler’s decision to mount this gun in the VK 9.03 that initiated work in this direction. On 11 September 1941, the Heeres Waffenamt was requested to produce 200 Geschütz 8202 for delivery between April 1942 and April 1943. Needless to say, progress was not so swift. In a July 1942 report providing an overview of the status of equipment development by the Heer, it was revealed that ten 2.8 cm Kw.K. 42 from a Versuchs-Serie (trial series) of 24 were available and that the rest of the contract was on track for completion by 1 October 1942, presumably referring to the order for 200 placed in September 1941. However, after this report, the gun simply vanishes and there is no evidence to suggest that any from the mass production contract were produced or that any were fitted to a VK 9.03 turret.

The 2.8 cm sPzB 41 heavy anti-tank rifle from which the 2.8 cm Kw.K. 42 was derived. Equipped with a progressively tapering barrel to increase muzzle velocity, this weapon operated on the squeeze bore principle. Seen here mounted on a standard field carriage, this weapon was also mounted on half-tracks and the four-wheeled Sd.Kfz.221 armored car. Source: warspot.ru
Around the same time as these efforts to upgun the VK 9.03 were being explored, engineers were also pursuing the idea of mounting a M.A.N.-designed HWA 1038 GL V8 diesel engine in the VK 9.03. Although there is little background on the developmental history of this engine and the thought process behind the decision to mount it in the VK 9.03, there are brief mentions of its relation to the VK 9.03. On 20 August 1941, a delegation from M.A.N. met with Herr Strunze, an engineer from Wa Prüf 6. In order to make the engine easier to start in wintry conditions, Strunze suggested that the engine be fitted glow flanges on the engine intake line and a fuel injection system to allow fuel already in the intake line to be easily ignited. Unlike the 2.8 cm Kw.K.42, this engine was at least trialed in both a VK 9.01 and a VK 9.03 (most probably one of the six trial chassis). As stated by a M.A.N. report from February 1942 on the development of diesel engines, the V8 had an output of 185 hp at 2,600 rpm, and work was underway to up this to 200 hp by increasing engine speed. Testing with a supercharger was also mentioned.
As with many other German tanks in production during late 1941, consideration was also given to adapting the VK 9.03 for operation in the hot, humid, and dusty environments such as might be found in the North African deserts of Libya and Egypt, or the southern reaches of the Soviet Union. Known as Tropen (literally ‘tropics’) modifications, these were intended to improve cooling and restrict the ingress of dust and sand. Typically, such modifications included enlarging the cooling air intake, installing a more powerful fan and extra filters, sealing exposed openings against dust, protecting the electrical equipment, and issuing a tarp and wider shovel to the crew. All of these measures were mentioned in a report on Tropen modifications from the Waffenamt dated 13 December 1941, which noted that testing was being conducted on the VK 9.03. This is not so surprising given that the first VK 9.01 were intended to be issued to the 15th Panzer Division (part of Rommel’s Afrika Korps), although there is no evidence that these plans were ever carried out. If the VK 9.03 were also intended to be deployed with similar units, then it stands to reason that Tropen modifications would have been required.
Despite these many setbacks and diversions, the VK 9.03 project refused to die. On 3rd December 1941, the Panzer II n.A. (VK 9.03) was included for the first time in the monthly reports compiled by the Amtsgruppe für Industrielle Rüstung (Group for Armaments Manufacture – abbreviated as Wa J Rü in German records), which set production targets for the next six months. According to this report, the first VK 9.03 would be completed in May 1942. In fact, this estimate was later revised in the January 1942 report, which projected the construction of one VK 9.03 in April, three in May and five in June 1942. Yet meanwhile, M.A.N was still struggling to finish the VK 9.01 0-Serie, which continued to trickle out of the assembly halls in tiny batches into 1942.
Evidently, the economic and technological constraints looming over VK 9.03 production were not factored into the Waffenamt’s schedules.


A representation of what the Panzerspähwagen II Ausführung M may have looked like had it entered service in 1942. It is shown painted in a coat of gray RAL 7021 Dunkelgrau, the standard camouflage scheme for German tanks at the time of this project’s development. Illustration by Alexe Pavel, funded by our Patreon campaign.

VK 9.03 for Four: The Panzerspähwagen II Ausf. M

The exact purpose of the VK 9.03 and its place in the German Army was complicated yet more by the bifurcation of the project into two separate tanks, which only served to further blur the lines between the various M.A.N designs for an improved Panzer II.
During its aforementioned summary of Tropen modifications released on 13 December 1941, the Waffenamt referred to a ‘Pz.Kpfw.II Ausf. H und M (VK 9.03)’. This marks the first surviving mention of an initiative to develop a specialized version of the VK 9.03 for armored reconnaissance. Known by various designations, including Panzerkampfwagen II Ausf. M (VK 9.03), Panzerkampfwagen II neuer Art (VK 9.03) Aufbau VK 13.03, Panzerspähwagen II Ausf. M, and Panzerspähwagen II Ausf. MAN, this was essentially an effort to mate the VK 9.03 hull with the superstructure and turret designed for the VK 13.03 (later known as ‘Luchs’).
Unfortunately, little is known about the genesis of this idea, as few documents concerning its development are known to have survived. Consequently, all that is available to piece together the history of this tank are a few disconnected fragments and off-hand mentions.
Nevertheless, the Pz.Sp.Wg. II Ausf. M did not simply spring out of the ether. In the aforementioned Schwerpunktprogramm (Priority Program) of 30 May 1941, in which the Heereswaffenamt had laid out its grandiose plans for long-range mass production of the VK 9.03, several different variants based on the VK 9.03 chassis were mentioned. Among these was a VK 9.03 Pz.Sp.Wg., of which 8,111 were deemed to be required for reconnaissance in various infantry, motorized, Panzer, pioneer, and Panzer-Jäger units. These would replace the less mobile wheeled armored cars that currently fulfilled these roles. It is therefore likely that the order to develop the Pz.Sp.Wg. II Ausf. M sprang from these requirements.
Ironically, this barren historical record is somewhat counterbalanced by the existence of a surviving data sheet for the Pz.Sp.Wg. II Ausf. M released on 5 March 1942, thanks to which we have access to a plethora of proposed technical specifications for the Ausf. M; even more so than the Ausf. H. These details provide an insight into what the Ausf. M may have looked like and its potential capabilities.
The primary difference between the Ausf. H and the Ausf. M was the superstructure and turret. Whereas the Ausf. H would likely have used a one-man turret similar to that designed for the VK 9.01, the Ausf. M lifted the superstructure and turret directly from the VK 13.03. This created sufficient space to add an extra crew member in the turret, thereby relieving the commander of his extra duties involved in servicing the main armament.
Asides from other minor changes to the specifications, in most other respects the Ausf. M remained the same as the Ausf. H. It retained all of the same major components, including the 200 hp Maybach HL 66 P engine, the distinctive VK 9 series suspension, and the wider Kgs 63/360/90 tracks. By keeping the same suspension and 36 cm wide tracks, the VK 9.03 maintained excellent flotation, having a ground pressure of 0.81 kg/sq cm. The proposed transmission and steering system, perhaps the most important components in the VK 9 series given the headaches they caused for their engineers, was not specified. Armor thicknesses also remained constant, with 30 mm on the front, 20 mm on the sides and rear, 10 mm on the deck, and 5 mm on the belly, as did the overall combat weight at 10.5 tonnes.
The armament remained unchanged too. Just like the Ausf. H, the Ausf. M would have had a 2 cm Kw.K.38 cannon and M.G.34 (Pz.) machine gun fitted to a stabilized mount in the turret. 400 rounds of 2 cm Pz.Gr.Patr. (armor piercing) ammunition and 2,100 rounds of 7.92 mm M.G.34 ammunition would be stowed within the vehicle, as well as 192 rounds of 9 mm Parabellum ammunition for an M.P.38 submachine gun. Initially, a T.Z.F.6 monocular gunsight would be employed by the gunner to sight these weapons, but later this would have been replaced by a T.Z.F.12b. Rotating periscopes in the turret roof would provide visibility for the crew members in the turret, whilst the driver employed K.F.F.2 periscopes to see out when his armored visor was closed.
As a reconnaissance tank, among the most important pieces of equipment carried onboard the Ausf. M would have been the radios. An Fu 5 set was listed on the data sheet, although Doyle and Jentz state that this would have been supplemented by an Fu 12 with a star aerial when it was issued to a Panzer Aufklärungs Abteilung (Armored Reconnaissance Battalion). This latter radio had a longer range and was therefore necessary for communicating with elements higher in the command chain.
Equipped with the 200 hp Maybach HL 66 P, the Ausf. M had a power-to-weight ratio of 19 hp/tonne and could attain a maximum speed of 60 km/hr on roads or 30 km/hr cross-country. With sufficient room for 235 litres of petrol, it could cover 290 km on roads or 175 km cross-country, impressive figures for the standards of the time that would have been well-suited for a reconnaissance vehicle. It was also expected that the tank would be able to scale a vertical obstacle of 30 cm, climb a 30% gradient, cross a 60 cm wide trench and ford 1.4 metres of water without preparation.
Whilst these estimated specifications promised to result in an impressive reconnaissance vehicle that would have been mobile and maneuverable, it is important to note that these are merely projections. No examples are known to have been produced and it is probable that the Ausf. M would have suffered from the same reliability problems as its counterparts if it used the same troublesome transmissions and steering units. There are also some contradictions in the figures as reported in the books Panzer Tracts 2-2 and Panzer Tracts 20-2, both of which have sections on the Ausf. M. The figures used here have been chosen by the author on the basis of what look to be the correct specifications.
Ultimately then, the Ausf. M was just another dead end in the convoluted VK 9.03 development process. The fact that it used the superstructure and turret of the VK 13.03 was especially revealing in that it pointed to the inescapable reality that the VK 9 was losing traction in the face of competition from other designs. Although its designers could not have known at the time, the Ausf. M foreshadowed the outright replacement of the VK 9.03 by the VK 13.03.

A surviving VK 13.03, which received the official designation Panzer II Ausf. L, on display at The Tank Museum, Bovington, UK. Nicknamed the ‘Luchs’ (Lynx) by the Heer, 100 of these tanks would be produced between 1942 and 1943. Capable of carrying a four-man crew and fitted with simpler, proven automotive components, the VK 13.03 replaced the VK 9.03 in the search for a new model Panzer II after a period of uneasy coexistence between the two designs. Incidentally, the raised bracket located at the front-middle of the turret roof is for an Orterkompaß, a navigation device later proposed for the VK 9.03 Panzerbeobachtungswagen. Source: The Tank Museum

Dashed Hopes: The Cancellation of the VK 9.03

Regardless of these numerous distractions and diversions, M.A.N. continued to push on with the construction of the six VK 9.03 Versuchs-Fahrgestell in preparation for a demonstration to be held in February 1942. However, even before these Versuchs-Fahrgestell had been completed, problems began to arise with the steering units. This was not an encouraging development, especially considering that the use of an advanced transmission and steering system to create a more mobile Panzer II was arguably the fundamental raison d’être for the VK 9 series. Indeed, similar issues with fickle three-stage steering units would also cripple the VK 9.01 project.
The impact of these difficulties in perfecting a working steering system were exposed in a meeting held on 27 December 1941 between M.A.N. staff and General Radlmeier. Herr Garnjost of M.A.N. informed Radlmeier that it was simply impossible to finish the three Versuchs-Fahrgestell in time for the February demonstration. In order to allow for some testing to be carried out as quickly as possible, an expedient solution involving the installation of a Kolben-Danek steering unit from the Panzer 38 (t) was proposed for the second Versuchs-Fahrgestell. All going well, this would allow for its completion by the end of January.
Meanwhile, the third Versuchs-Fahrgestell would await the arrival of a Maybach steering unit, which was expected to delay its completion until the end of February. It is not specified precisely which kind of Maybach steering unit was earmarked for this third trial chassis, but it is possible it could have been the LGL 15319 that was also fitted to the majority of the VK 9.01 and contracted for installation in the first VK 9.03 Versuchs-Fahrgestell ordered in 1940.
Put simply, this meeting revealed that VK 9.03 production was dependent upon the resolution of the difficulties producing and using the steering units. This impression is reinforced by a M.A.N. meeting held on 10 January 1942, where officials openly questioned the possibility of mass producing the VK 9.03 with a three-stage steering unit and broached alternative solutions. The solution they proposed was replacing the steering unit with a M.A.N. design, presumably of more conventional operation. It was hoped that this would allow for the assembly of the first VK 9.03 hull in June 1942 and the production of the first complete series production tank at the beginning of August that same year.
In addition to the steering unit fiasco, this meeting also provides a glimpse into a less well-covered aspect of the VK 9 family’s history. Due to the loss of Daimler-Benz records after the war, almost nothing remains concerning the design, development, and production of the VK 9.01 and VK 9.03 superstructures and turrets. Nevertheless, it appears from M.A.N. reports that the company struggled to produce a workable design in time, as there are allusions to delayed delivery of blueprints and drawings in surviving M.A.N. records. According to this report, missing turret floor and turret equipment schematics had pushed production back by four months and meant that M.A.N. would be unable to complete the first Aufbau until July 1942. Of course, without Daimler-Benz reports, it is not possible to evaluate the reasons behind these delays.
Nevertheless, the results of a trial carried out with one of the VK 9.03 Versuchs-Fahrgestell in January 1942 suggested that there were more pressing issues with the automotive components. In a frustratingly enigmatic report of a meeting held between all the major M.A.N. and Wa Prüf 6 figures involved with the VK 9.03 (including Kniepkamp), the results of a 530 km test drive of a VK 9.03 Versuchs-Fahrgestell were discussed. It is not entirely clear what the exact automotive configuration of this VK 9.03 trial chassis was, but the minutes indicate that it was not considered sufficient evidence to make a judgment on the three-stage steering units before comparative trials were carried out in February. Even so, the curious note that ‘in no case should the remarks from Blank [a mechanic involved with the trial] be allowed to fall into outside hands’ seems to imply that the results were less than stellar. Certainly, much to Kniepkamp’s dismay, M.A.N. representatives brought up the idea of replacing the steering units with a conventional clutch-brake system as installed on other Panzers.
Unable to stave off the inevitable any longer, M.A.N. and Wa Prüf 6 agreed on 3 February 1942 that the first 15 VK 9.03 series production hulls would use a simple clutch-brake steering system and a conventional Z.F. manual transmission. This was a far cry from Kniepkamp’s vision of a revolutionary mobility upgrade for the Panzer II and a stark indication that the VK 9.03 had reached a technological cul-de-sac.
The next mention of the VK 9.03 comes from a conference between Albert Speer and Hitler on 22 March 1942. During this meeting, Hitler agreed that the VK 9.03 could be fitted with an HL 66 engine, SSG 48 transmission and a multiple-stage steering unit derived from B.M.M.’s design for the Panzerkampfwagen 38(t) n.A. light tank. It was estimated that this combination of automotive components could result in speeds of up to 60 km/h being obtained.
Amazingly, just five days later on 27 March 1942, the entire VK 9.03 project was canceled in a sudden and abrupt volte-face. In the new production programme issued by the Heeres Waffenamt, M.A.N. was to dispense with the production of 250 VK 9.03 and 250 VK 13.03 in favor of producing 500 VK 13.03 instead. In a context of greater economic rationalization presided over by Speer, who had been appointed Minister of Armaments following the death of Fritz Todt in a plane crash on 8 February 1942, there was simply no room for the experimental and wasteful VK 9.03.

A Failed Resurrection: The VK 9.03 after March 1942 and the VK 9.03 Panzerbeobachtungswagen

At the time of the cancellation of the VK 9.03 in March 1942, it is unclear how many of the Versuchs-Fahrgestell had been completed. It is known that at one point as many as six were under contract, although later reports from 1942 only mention three under construction. Moreover, at least one of these hulls was used in trials and test drives, including the one discussed in January 1942 and the aforementioned trials with a M.A.N. diesel engine mentioned in February 1942.
The history of German trials vehicles is understandably shadowy and obscure. Spared from fighting on the front, these vehicles were rarely photographed and only occasionally mentioned in reports. Even so, they were often retained by the factories or by the Heereswaffenamt as testbeds for trialing new equipment. Such was the case with the VK 9.03, one of which was reportedly being used by Maybach as late as 1945 for testing a new HL 90 engine (14 of these were produced between 1941 and 1944), a preselective Olvar transmission and a Bauart Renk hydraulic steering unit; a fitting end for a design defined by its relationship to experimental automotive components. Unfortunately, no photographs of these trial chassis are known to have survived and details remain scarce.
More puzzlingly, work on an artillery observation variant of the VK 9.03 appears to have continued after March 1942. According to a Wa Prüf 6 report released on 1 July 1942, work was ongoing on designing a VK 9.03 Panzerbeobachtungswagen (armored artillery observation vehicle) for motorized artillery and Panzer Regiments, with the production of 30 contracted vehicles expected to start in 1943. Like the VK 9.03 Ausf. M, the impetus for this design probably dated back to the 1941 Panzerprogramm, which stipulated the provision of VK 9.03 for artillery observation purposes. However, this does not explain why the Waffenamt had elected to continue work on this specific variant, as it makes little sense to continue working on a design for such a specialized version, given that such vehicles were usually converted from standard mass-produced vehicles. This is a prime example of how the many gaps in the documentary record render it difficult for modern researchers to piece together the logic (or lack thereof) behind armored vehicle development.
Whatever the story behind the VK 9.03 Panzerbeobachtungswagen, a single Versuchsgerät VK 9.03 mit Kuppel 1303 B (trial equipment with the cupola 1303 B) was reported as having been completed by September 1941. Usually translated as ‘device’ or ‘equipment’, it is unclear precisely what ‘gerät’ refers to. Possible answers include a piece of specialized equipment or, noting the reference to a cupola, a turret design, but this is just speculation.
In order to fulfill its purpose, the VK 9.03 Panzerbeobachtungswagen was to be fitted with a rangefinder, Orterkompaß (a kind of orientation compass that could be installed on top of the turret of the Luchs, Panzer IV, Panther and Tiger), observation equipment and appropriate radio sets.
Whilst it may have succeeded in temporarily outlasting its parent tank design, the VK 9.03 Panzerbeobachtungswagen almost certainly suffered the same fate as its relations. Asides from this brief reference, there are no further known references to this vehicle available.

The Orterkompaß 38 (OKo.38) showing the compass itself, its special 300 mm long support, and its base. This device, or one similar to it, was earmarked for the VK 9.03 Panzerbeobachtungswagen. Derived from a type of compass developed for the Luftwaffe in the 1930s, the Oko.38 was intended to assist with driving at night or in bad weather. These would have been mounted on small rectangular plates welded to the top of tank turrets. The cylindrical support was designed to increase the distance between the compass and the tank, thereby reducing magnetic interference from the steel. Although a few examples survive until this day, there is little evidence that these were ever mass produced or widely used. Source: panther-ausfuehrung-g.blogspot.com

Doomed to Die?: The VK 9.03 in Retrospect

The VK 9.03 was a flawed design that would have been unsuitable for mass production and out of its depth on the battlefields from 1942 onwards. Although the new automotive components envisaged for this tank could have resulted in a more mobile Panzer II, the complexity and unreliability of these various transmissions and steering units ultimately proved to be a critical issue.
Worse still, the VK 9.03 did not offer any other sufficient improvements over the VK 9.01 and the Panzer II Ausf. F then in production, namely in the realms of firepower and protection. Consequently, the failure of the transmissions and steering units undercut the entire purpose of the VK 9.03 since, without those features, there was nothing left to justify its existence. This unfortunate fact was made all the more apparent by the emergence of the VK 13.03, which provided all of the benefits of the VK 9.03 in a tank able to accommodate a four-man crew.
Yet, in the chaotic and irrational German tank procurement system of the mid-war period, the existence of deep flaws did not always automatically result in cancellation of the entire project. Instead, designs often gained a momentum of their own and were able to devour funds, resources, and time, even if the Heer had no specific need or desire for them. Such was the case with the VK 9.01, which outlasted its successor and continued in limited production until 1943 despite suffering from the same problems as the VK 9.03. Evaluated with this in mind, the VK 9.03 was also the victim of circumstance.
At the time when the crucial decisions were being made about the VK 9.03 production schedule, Albert Speer, the new Minister for Armaments Production, was attempting to rationalize the Nazi economy and push it towards a total war footing. Ironically, the idea expressed in the Panzerprogramm 41 to mass produce an entire family of armored vehicles on the VK 9.03 hull represented a rare instance of sensible joined-up thinking in the procurement process, but given the doubts among M.A.N. officials that mass production of the VK 9.03 could ever be achieved in the near future, this was little more than a pipe dream. Whilst the cancellation of the VK 9.03 was not a foregone conclusion, these production obstacles and its growing redundancy in the face of superior alternatives and changing economic circumstances conspired to kill the project in 1942.
Nevertheless, whilst this represented the end of the VK 9 series of armored vehicles, efforts to improve the Panzer II persisted. These would culminate in the VK 13.03 or Panzer II Ausf. L, better known as the ‘Luchs’ (Lynx), which built upon some elements of the VK 9.01 and VK 9.03 whilst dispensing with some of the more problematic aspects of these designs.

Specifications (Ausf. H & M)*

Dimensions (L-W-H) M: 4.63 x 2.48 x 2.05 metres
Total Weight 10.5 tonnes
Crew H:3 Men (Commander/Gunner, Radio Operator, and Driver)
M:4 (Driver, Radio Operator, Commander, Gunner)
Propulsion Maybach HL 66P producing 200 hp at 3,200 rpm
Transmission H: Maybach 8-speed preselective VG20417 transmission LG 45L (LGL 15319) steering unit (these components for the first Versuchs-Fahrgestell)
Maximum speed H: 65 km/h on roads
M: 60 km/h (road), 30 km/h (off-road)
Range M: 290 km (road), 175 km (off-road)
Suspensions Torsion bar, 30 cm ground clearance
Armament H: 1x 2 cm Kw.K.38 cannon, 1 x M.G.34 (P)
M: 1x 2 cm Kw.K.38 cannon (400 rounds), 1 x M.G.34 (P) (400 rounds), 1 x M.P.38 (192 rounds)
Armor (hull/turret front) 30 mm frontal hull and turret
20 mm sides and rear
10 mm deck
5.5 mm belly
Production At least 1 hull

*Note that these are projected specifications as no series production VK 9.03 are known to have been completed.

Sources and Further Reading

Doyle, H.L., and Jentz, T.L., Panzer Tracts No.2-2 Panzerkampfwagen II Ausf. G, H, J, L, and M: Development and Production from 1938 to 1943 (Maryland: Panzer Tracts, 2007).
Doyle, H.L., and Jentz, T.L., Panzer Tracts No.20-2 Paper Panzers: Aufklaerungs-, Beobachtungs-, and Flak Panzer (Reconnaissance, Observation, and Anti-Aircraft) (Maryland, Panzer Tracts, 2002).
Doyle, H.L., and Jentz, H.L., Panzer Tracts No.23 Panzer Production from 1933 to 1945 (Maryland: Panzer Tracts, 2011).
Spielberger, W.J., Der Panzer-Kampfwagen I und II und ihre Abarten: Einschließlich der Panzerentwicklungen der Reichswehr (Stuttgart: Motorbuch Verlag, 1974). Translated into English as Panzer I and II and their Variants: From Reichswehr to Wehrmacht (Pennsylvania: Schiffer Publishing US, 2007).
Antonov, V., ‘Schwere Panzerbüchse 41’ (Russian). English version HERE.
Jairo, ‘Orterkompass en el Panther Ausf. G’
Pasholok, Y., ‘Pz.Kpfw.II Ausf. G: The Fruit of Unending Labour’ (Russian). English version HERE.

Bibliographical Comment

Unsurprisingly for such an obscure and poorly documented tank, little has been written on the VK 9.03. Although the VK 9 series was mentioned in the older, classic reference books concerning Second World War German armored fighting vehicles, most of the information presented in these works is based on faulty post-war Allied intelligence reports or assumptions, contributing to many errors and misleading statements. This has contributed to the proliferation of misunderstanding and confusion concerning this series of tanks in print and online media, with one salient example being the mislabelling of the Pz.Sfl.Ic tank destroyer (based on the VK 9.01 chassis) as the Panzer II Ausf. H (VK 9.03) in the popular online game War Thunder.
The most important and reliable work of reference on the VK 9.03 is Panzer Tracts 2-2 written by the doyens of German Second World War AFV history, Jentz and Doyle. This book provides a wealth of information derived from primary source material, helping to set the record straight without indulging in extensive speculation. An earlier work by the same authors, Panzer Tracts 20-2, offers a less comprehensive summary of the VK 9.03, though readers should note that there is some minor contradictions between the two, possibly the result of typos in the text.
A detailed account of the VK 9 series based on the work of Jentz and Doyle is also offered in an article by Russian historian Yuri Pasholok that has been translated into English. This article, as well as the others in the Panzer II series, are particularly useful for contextualising the VK 9.03 and investigating its links to contemporary designs.
Asides from the works mentioned above, all other sources of information concerning the VK 9.03 should be treated with caution given their tendency to rely on outdated reference material or other confused commentators. Until any new information surfaces concerning these machines, Panzer Tracts 2-2 will remain the definitive source of information on the VK 9.03.

Categories
WW2 Czechoslovak Prototypes WW2 German prototypes

Panzerspähwagen II Ausführung Škoda

Germany/Protectorate of Bohemia and Moravia (1940)
Light Tank – 4 Prototypes Built

On 15 September 1939, the German Heereswaffenamt (Army Weapons Office – HwaA) issued new specifications for a fast, more heavily armored scout reconnaissance tank with 30 mm front armor, a 2 cm or 3.7 cm main gun and a top speed of 50 km/h. These were originally sent to the German firm MAN but, on 31 July 1940, they were also sent to two other companies, Škoda and BMM (the former Czechoslovak CKD).
The prototype Panzer T-15 light tank looks like an improved Panzer II tank but there were many differences. Its factory designation was the Škoda T-15. The first two prototypes were only built in mild structural steel.

The Panzer Späh Wagen II Ausführung Škoda, previously designated the Škoda T-15. Photo: Bundesarchiv

Name

A German Wa Prüf 6 (the German design office for armored vehicles and motorized equipment under the Heereswaffenamt – Army Ordnance Department) document dated 5 March 1942 shows the factory name Škoda T-15 being scratched through and the name Panzerspähwagen II Ausführung Skoda (Armored Scout Car II version Škoda – Pz.Sp.Wg II Ausf.Skoda) written in its place.

German Wa.Prüf. 6 original document notes that show the change of name. Photo: Herbert Ackermann

Design

The company Škoda-Werke’s T 15 design had welded armor, an improvement over the Czechoslovak built Panzer 38(t) tank’s bolted and riveted armor. The armor on the front of the turret and hull was 30 mm thick and the sides were 25 mm thick. The turret had a new curved shape with a commander’s cupola. The main gun fitted on the prototypes was the 3.7 cm Škoda A11 anti-tank gun (German designation 3.7 cm KwK 38(t) L/47). It could fire armor-piercing (AP) shells and high explosive (HE) fragmentation shells.

On 4 January 1943, the Panzerspähwagen II Ausführung Skoda prototype was shown to Hitler and senior German officers. Photo: Bundesarchiv
There was no hull machine gun. A 7.92 mm MG34 machine-gun was mounted in the turret. The driver and radio/operator were positioned at the front of the tank. Both had armored vision ports like the later Panzer II tanks.
The tank was powered by a Škoda water-cooled V8 10.8 liter 245 hp gasoline/petrol engine. The transmission had 6 forward gears and one reverse.
The suspension was different from other tanks under construction at that time. It had four pairs of large road wheels on semi-elliptic leaf springs. There were three pairs of smaller track return rollers. The drive wheel was at the rear while the idler was at the front.

Rear view of the Škoda, looking at the engine bay. The Panzerspähwagen II Ausführung Skoda prototype had four pairs of large road wheels on semi-elliptic leaf springs and three pairs of track return rollers. Photo: SOURCE
The first prototype T-15 was built in October 1941, and the second in December 1941. Tests were conducted during March and June of 1942. Further tests were completed between July and October at Kummersdorf, 25 km south of Berlin.

German Wa.Prüf. 6 original document that shows some of the vehicle’s specifications. Photo: Herbert Ackermann


Illustration of the Panzerspähwagen II Ausführung Škoda, also known as the Škoda T-15. Produced by Mr. Adrielcz, funded by our Patreon Campaign


Panzerspähwagen II T15 by adrielcz

Alterations

Alterations were made to the original design on the later prototypes. The turret shape was changed. The side armor was curved differently. An armoured driver’s vision port was fitted to the side of the chassis. The commander’s cupola was also completely redesigned. Instead of the Czech ZB.37 machine gun a German 7.92 mm MG.34 was installed. The 37mm A11 gun remained in place, but Škoda’s engineers also provided for the possibility of arming the tank with a 47 mm gun. The same Wa Prüf 6 document dated 5 March 1942 mentioned earlier showed that it was intended to mount a 5 cm PaK 39 L/60 on the production tank in a Daimler-Benz built turret.

Škoda-Werke’s redesign of the T 15 prototype wooden mockup, with improved sloping frontal hull armor, smaller turret and relocated exhaust. Photo: Yuri Pasholok

Fate

Škoda had signed a contract to build five prototypes but only built four. Construction of the fifth was stopped in early 1944 as the Panzer II Ausf.L Luchs (Lynx) was already in mass production.
Škoda completed the construction of the fifth prototype in May 1945, having restarted work in January. After the war finished, it was shown to the new Czechoslovak Army in July 1946 but no orders were placed. The Škoda tank design department used the chassis to develop different light tank projects which they called the T 15A, T 15S and T 16. They stayed as drawings. No prototypes were built.

The Pz.Sp.Wg II Ausf.Skoda prototype tank undergoing trials. There appears to be a build up of mud between the road wheels. A platform has been constructed on the right side of the turret for testing staff to have somewhere to sit as they observe what is happening. Photo: Bundesarchiv

Specifications

Dimensions (L-W-H) 4.58 x 2.17 x 2.16 meters
Total weight, battle ready 10.8 tons
Crew 4 (commander, gunner, radio operator, driver)
Propulsion Skoda T-15 8-cylinder, petrol 220 hp
Suspension semi-elliptic leaf springs
Speed (road) 50 km/h
Range 200 km
Armament 3.7 cm Skoda A11 (3.7 cm KwK 38(t) L/47), 7.92 mm MG34
Armor 8 mm – 30 mm
Total production 4 (+1 post war)

Sources

warspot.ru (Russian)
Pavel Pilar “Pruzkumne tanky Skoda T-15 a Praga TNH nA”, HPM c.3 / 2000
I.Pejcoch, O.Pejs “Obrnena technika” №6
“Hobby Historie” 2011 №10
Hilary Doyle and Thomas L. Jentz, Panzer Tracts No. 11-2: Aufklaerungspanzerwagen (Full and Half-Track Armored Reconnaissance Vehicles) H8H to Vollkettenaufklaerer 38.