Categories
WW2 Czechoslovak Prototypes WW2 German Prototypes

Škoda SK 13

German Reich/Protectorate of Bohemia and Moravia (1944-1945)
Light Tractor – 1-2 Prototypes Built

At the beginning of the Second World War, Germany faced a total resource crisis, especially in terms of fuel. In a panic, the country’s leadership sought for a cheap and plentiful equivalent. Along with synthetic fuel, steam engines were one of many potential substitutes considered. The Škoda SK 13 was amongst the late-war survivors of this technology, combining both archaic and modern elements.

Not From a Good Life

Many European politicians’ hopes for victory at the early stage of World War Two were based on the fact that a lion’s share of global resources was controlled by the Allies or, at least, were beyond Hitler’s reach. The Allies outnumbered the Axis ~3 times in population and ~8 times in territory. Moreover, the British Navy managed to practically cut off the aggressor from the rest of the world.

The only strategic resource that the Germans had in abundance was coal. On the other hand, oil production covered less than 9% of the state’s demand. Only 11% of imported oil came to the Third Reich from Romania, which was accessible by land, another 1.7% from the USSR, and the rest came from overseas. In its article of September 7th, 1939, the American magazine ‘The Oil and Gas journal’ emphasized:

“At this time, the South American countries are the principal suppliers of nations now at war, as well as many of the neutral countries of Europe, with the exception of the U.S.S.R. and Romania, which have crude oil in excess of their requirements. It is apparent that it is to these South American countries and the United States that these European countries must look for any large increase in their requirements as a result of war activities.”

World map showing crude-oil production by countries based on daily average output in barrels during the first six months of 1938. Map includes representative tanker routes. Source: The Oil and Gas journal, Vol. 38, Iss. 17, ‘Few Nations Supply War Oil Needs’ article

A week later, an article by H. Stanley Norman titled ‘The Nazi War Machine in the Face of Oil Shortages’ appeared in the same magazine, predicting that the German shortage of liquid fuels would begin by the middle of 1940. Alongside that, the presence of large reserves of oil and oil products in the German Reich, a significant production of synthetic gasoline and diesel fuel from coal, as well as ethyl alcohol from potatoes, were mentioned.

Actually, this is what made Blitzkrieg essential for the Wehrmacht: Germany simply could not afford a long-lasting war. In September 1939, the resources of the western half of Poland went under German control. In April 1940, the resources of Norway (with the path to the Swedish Kiruna ore) went the same way. In June, 1940, the French State signed the ‘reconciliation’, so the Lorraine iron ore, along with many resources from the French colonies, became accessible to the Reich.

By the beginning of 1941, oil and petroleum products came to Germany, in certain volumes, from Stalin’s Soviet Union, as well as from Romania and Hungary, which had completely fallen under German influence. Of course, it was no longer possible to legally bring anything from across the oceans, but some bits were still smuggled – even from Britain (via Spain).

In addition, allied Italy turned out to be resource dependent on Berlin. The Germans lacked oil and some metals, while the Italians lacked almost everything. Even though military production (both aviation and military shipbuilding) was well developed, the basic industries – metallurgy, chemistry, machine tool construction – lagged far behind or depended on the import of raw materials. With the entry of Italy into World War II, Hitler had to practically take Italy on the balance sheet and to supply petroleum products, as well as iron ore with coal for metallurgical plants.

Expenses on Italy were comparable to the Reich’s own consumption. In 1942, the last year before Italy surrendered, the consumption of motor fuel in Germany (without the Wehrmacht) was equal to 357,000 tons, and exports to Italy – 285,000 tons. Fuel supplies for the Italian Navy were 280,000 tons, while the German Kriegsmarine got only 140,000 tons.

According to the experience of the previous world war, everyone knew in advance that the need for oil products in wartime increases by about 3 times compared to peacetime. Already in 1937, the famous German economist F. Freudenberg calculated the German need for oil imports in the event of war at 20 million tons, and it was one of the most optimistic forecasts. This level was not achieved, even though the Reich’s own oil production (including annexed Austria, Czechoslovakia, and French Alsace) increased in the period from 1940 to 1944 (according to the 1st quarter in terms of the year) from about 1.5 million tons to 2 million tons. The country could not fully provide itself with essential resources.

By the end of the war, Germany’s fuel supply had seriously deteriorated. This was due both to the destruction of synthetic fuel production plants and to the crisis of coal mining enterprises that supplied raw materials to these plants. The fuel supply to the army and economy of the German Reich in the first quarter of 1945 was kept at the level of 23,163 barrels per day, i.e. 10 times less than in the first quarter of 1944.

Hence, various “ersatz methods” had become widespread, amongst which were:

Mercedes-Benz 170V (W136) mit Holzvergaser (with wood carburetor). About 500 thousand cars were equipped with gas generators by 1944. In other words, almost all non-military German cars were refueled not with gasoline, but with firewood and brown coal. Moreover, gas generators were also installed on training tanks. Source: drewnozamiastbenzyny.pl

Another ‘living fossil’ resurrected by the fuel crisis was the steam engine. It seemed to be a great substitute for gasoline engines, so in December 1944, works began on creating a steam-powered tractor named SK 13. The vehicle used Czechoslovak groundworks: a Škoda Sentinel steam truck engine and a Jagdpanzer 38(t) tank destroyer, based on the chassis of the Pz.Kpfw.38(t) light tank, developed by Alexei Surin. The mass production of the vehicle was launched in spring of 1944 at BMM (Böhmisch-Mährische Maschinenfabrik AG, the name of the Českomoravská Kolben-Danek (ČKD) company during the German occupation of Czechoslovakia). The excellent characteristics and the cheapness of the chassis made it possible to build various new vehicles on its basis, including tank destroyers, artillery and, of course, tractors.

Design

Hull

Early version of the SK 13. Note the missing roof and water/fuel containers. Source: armedconflicts.com

For the construction of the SK 13, the base of 38(t) was significantly altered. One of the most important changes was the increase in length. The hull was lengthened and two roadwheels were added on each side, resulting in six roadwheels on each side. They were interlocked on three bogies with spring suspension. The location of the sprockets at the rear of the vehicle was not changed. The idlers, in turn, remained in the front. Despite the relatively large diameter of the roadwheels, a set of two return rollers was retained as part of the chassis.

Later version of the SK 13, in its final configuration. Note the roof and large fuel and water containers in the rear part of the hull. Source: armedconflicts.com

To solve the main layout problems, it was proposed to seriously redesign the hull. The existing hull was extended by about a quarter, which allowed it to maintain an acceptable ground pressure and internal volume. The inclined frontal plate of a small height was kept, and boxes were added above the tracks. The design of the rear part was also revised several times due to multiple changes to the technical task.

There is no information about the armor layout of the tractor. It can be assumed that the use of an existing chassis led to the preservation of the armor of the base Jagdpanzer 38(t). In favor of this version, in particular, are the weight indicators of the prototype. The steam tractor could have had armor from 8 to 60 mm thick, capable of protecting the crew and components from small arms and some artillery systems. This made it possible to use the vehicle in some combat formations with other armored vehicles without fear for its safety.

Engine

Škoda Sentinel boiler scheme. Source: topwar.ru

The chassis was not the only part that was proposed to be borrowed from existing vehicles. Steam boilers with reciprocating machines for use as a power plant were supposed to be taken from the Škoda Sentinel steam truck.

These trucks were equipped with 70 hp steam engines and could carry up to 5 tonnes of cargo. The standing, tubular boiler, with a heating surface of 5.06 square meters, was located in the front part of the truck. It could burn coke, coal, charcoal, wood, and briquettes in it, but coke was the most suitable. The boiler was also equipped with a pressure gauge, a water level mark with a safety valve, and the steam output was controlled by a slide valve. Preparation for driving took about 30 minutes.

Škoda Sentinel’s boiler. Source: sentinel.cz

With a bore diameter of 170 mm and a stroke of 230 mm, a steam pressure of 19 atp and at 250 rpm, it delivered 70 hp. The crank mechanism was then equipped with a patented differential acting on the chain pinions. The transmission of power to the fixed rear axle was by massive Gallo chains, which drove the double wheels, freely rotating on the axis. The average speed of the truck was about 25 km/h. Lubrication of the steam engine and chains was by an oilcan, separate for each side.

The furnace of the boiler of the later version: water pipes are located in the spiral recesses. Source: topwar.ru

The Škoda SK 13’s steam engine was developed based on the units of the Škoda Sentinel truck, some of which were used in the basic configuration, without any changes. The basis of such an engine was a cylindrical steam boiler. A cylindrical furnace for burning solid fuel was placed inside the outer casing, through which a large number of tubes passed. Water was poured between the furnace and the outer body of the boiler. During the combustion of fuel, water entered the tubes of the furnace and came into contact with its walls. At the same time, the water boiled, after which steam passed through the superheater and entered the cylinder of the piston machine.

To supply air to the fuel, the lower lid of the furnace was made in the form of a movable plate with water, which performed the functions of an ash pan (a container for solid fuel combustion products). Air access was carried out through a gap between the furnace body and the lower lid, the dimensions of which could be changed using a special lever mechanism.

The SK 13 in its final configuration on trials. Source: armedconflicts.com

The SK 13 tractor received two steam boilers, both of which were mounted in the center of the hull, one next to another. The piston engines of the two engines were mechanically connected to the rear part of the hull, into the existing transmission. Containers for water and fuel were placed in the free space of the hull. In the later version of the SK 13, fuel and water were placed in two large rectangular containers installed in the rear part of the hull. It is noteworthy that, due to the larger hull and hence larger volumes for fuel, it was possible to achieve a significant increase in the range compared to the Sentinel truck. On the other hand, the increase in the amount of fuel and water led to an additional mass of the tractor.

Boiler Donor: Škoda Sentinel

In the beginning of the 1920s, a new automobile department in the Škoda factories in Pilsen was established. In 1923, the management of the company purchased licenses for the production of the French Hispano-Suiza passenger car and steam trucks from The Sentinel Waggon Works Ltd., Shrewsbury, England (United Kingdom). Part of the British license was also the technology of the steam-powered cars. This was not a new thing in Czechoslovakia, as they were preceded by several vehicles ordered by the Ministry of National Defense in Prague. For example, Kopřivnická vozovka (later known as Tatra) was engaged in the production of steam cars and buses many years earlier. The machine shop in Adamov also tried to produce a model of steam truck under the license of a British company, Richard Garrett & Sons Ltd., Leiston, Suffolk.

Plans of the Škoda Sentinel truck, model 1925. Source: sentinel.cz

At that time, the steam engine had a number of indisputable advantages over the gasoline one, such as its flexibility and that it accelerated quickly. Steam-powered vehicles comfortably climbed steep hills and were easily controlled by a single shut-off valve. It was also possible to stop the trucks immediately by simply closing the valve, as the engine worked as a compressor and braked. Another advantage was lower oil consumption, as, at the time, it was topped up daily in cars. Its low rotations per minute (~300) played another important economic role, by reducing the wear-out of particular parts of the vehicle. However, the far slower start of the steam car proved to be disadvantageous, as the boiler had to be heated first.

The Škoda Sentinel truck. Source: sentinel.cz

The Škoda-Sentinel was, according to the standards of the time, a truck of classic design. It was capable of operating in the most difficult conditions. More than that, thanks to the possibility of flexible operation of the steam engine, the truck also proved itself well in steep terrain. This was demonstrated during Czechoslovak Army tests in 1923 of several imported vehicles, in which the Ministry of Railways also participated. The tests then took place on the Prague – Brandýs nad Labem-Stará Boleslav – Mochov – Prague line. The results were satisfactory and Škoda’s factories, which were looking for production possibilities for their new vehicle department in Pilsen, saw new profitable opportunities and therefore bought a license from the United Kingdom. The vehicle was introduced in many versions: as a flatbed, one-sided or three-sided dump truck, sprinkler or garbage truck, and also as a city omnibus or rail vehicle. Some continued to serve long after the Second World War and were gradually taken out of service only due to the lack of spare parts.

Crew

The crew of the experimental armored vehicle consisted of three: driver, commander, and engineer, who operated the steam boilers and reciprocating machines. In addition to controlling the parameters, the engineer had to throw coal into the furnaces, as well as regulate the water supply to the boilers. Direct control of the car, such as the choice of speed and direction of movement, was carried out by the driver using a set of levers and pedals.

Trials

In 1944, Škoda completed the development of the SK 13 project and built the first prototype. During the assembly and preliminary tests, it underwent some changes, primarily related to the exterior design. In particular, a light roof and containers for coal and water were added, as well as steps being installed on the upper frontal part of the hull to make the process of getting inside easier.

The SK 13 in its final configuration on trials. Source: armedconflicts.com

During the tests, it was found that the steam engine was able to accelerate the SK 13 tractor only up to 12-15 km/h. The transported fuel and water supply was only enough for a range of 150 km. Apparently, these figures only concerned driving on roads, whereas, when driving over rough terrain, performance dropped significantly. It is not difficult to notice that in terms of its mobility performance, the steam tractor was significantly inferior to the existing gasoline technology and could not compete with it in any way. Even efficiency in terms of fuel cost was not enough for the SK 13.

Tests of the SK 13 prototype led to two main conclusions about the future of steam technology. The first concerned the fundamental possibility of creating tractors or other military vehicles, including armored ones, with steam engines. The second conclusion imposed new requirements on steam engines for such equipment. The tests clearly showed that two boilers from the outdated Škoda Sentinel truck, with a capacity of 70 hp each, could not provide the required mobility for a relatively heavy and large tracked vehicle.

Due to a number of factors, the steam tracked vehicles of Czechoslovak design were not adopted by the German Army. For this reason, until the end of the war, the problem of fuel shortage was solved by other methods, including the widespread use of gas generators using firewood or coal chips. In addition, the operation of a certain number of steam engines continued. However, this did not last, as in spring 1945, Germany capitulated, eliminating the need of creating military vehicles with alternative power plants.

Škoda SK 23 and BMM SK 33 Projects

Soon after the construction of the updated SK 13, a second participant joined the work. Škoda continued to develop the existing project of a steam tractor for troops, resulting in a vehicle under the designation SK 23. As in the case of the SK 13, a ready-made chassis was proposed in a modified form. At the same time, it was planned to use steam engines of a new type supplied by Krupp. Due to the use of modern steam engines, it was supposed to provide a significant increase in performance compared to the previous SK 13. There were supposed to be certain advantages in speed and power reserve. The efficiency of operating the new steam engine, in turn, had to be ensured through the use of cheap fuel. Due to various production and administrative reasons, Škoda was unable to build a SK 23 prototype for testing. This project never left the drawing board. Various factors contributed to this, mainly problems at the front and the need to focus on the construction of other equipment.

Model of the SK 23 tractor. Source: valka.cz

Based on the test results of the SK 13 machine, the company BMM proposed its own concept, which resulted in the appearance of the SK 33 ‘Dampfschlepper’ project, created in two versions (differing only by the steam engine used). In order to increase the mobility of the tractor, it was proposed to reduce the weight of the structure and increase the power of the steam engine. Due to the removal and lightening of certain components, the curb weight of the tractor was reduced to 18 tonnes. The power of each of the two engines was to be increased to 80 hp. Thus, the specific power could grow to 8.7-9 hp per tonne with some positive implications on mobility.

The BMM SK 33 project suffered the same fate as the rival company’s SK 23. By the end of 1944, the situation on the Eastern Front had seriously deteriorated. In addition, Allied troops were developing an offensive in Western Europe. In such conditions, the industry of Germany and the occupied states no longer had the opportunity to engage in prospective projects, as they could threaten the fulfillment of other more pressing orders. As a result, the Czechoslovak industry focused on the production of other vehicles and a lot of new developments were canceled, including the BMM SK 33 steam tractor.

SK 33 ‘Dampfschlepper I’ tractor. Source: valka.cz
SK 33 ‘Dampfschlepper II’ tractor. Source: valka.cz

Side Note – Possible Inspiration Source for Wargaming

In 2022, Wargaming introduced a branch of Czechoslovak heavy tanks in their World of Tanks (WoT) game. All of the vehicles presented might be, at best, undiscovered and poorly-developed concepts. It is more likely that in reality they are just fakes without any documentary evidence, created by the developers of the game inspired by some real prototypes (like they earlier did with the Polish medium tank line or Czechoslovak premium medium tank Škoda T 27, which is just an elongated and heavily armed version of real Škoda T 17 light tank).

Czechoslovak ‘tech tree’ as presented in WoT. Source: Wargaming Wiki

The tier VIII of the branch is named TNH-105/1000. This designation resembles real ones. Some Czechoslovak vehicle blueprints of that time have the name of the developing company, gun caliber, and muzzle velocity (e.g. TNH-57/900 light tank) on them.

TNH-105/1000 as presented in WoT. Source: World of Tanks Official Youtube Channel

Description from World of Tanks:

In the latter half of the 1940s, ČKD and Škoda engineers developed a joint project for a heavy tank for the Czechoslovakian Army and for possible export purposes. The TNH 105/1000 design was based on available concepts of German and Soviet tank-building and original ideas from Czechoslovakian engineers. In November 1949, the Communist Party of Czechoslovakia decided to discontinue the development of its own vehicles and switched to producing a licensed copy of the Soviet T-34-85 tank. All activity on the TNH 105/1000 was canceled and no prototypes were ever built.

The hull of the vehicle resembles th SK 13 steam tractor in many important aspects:

  • Both hulls have almost identical proportions;
  • Both hulls have a Surin-type suspension with three bogies;
  • The drivers of both vehicles are located in the right part of hull’s front;
  • The chassis of both vehicles have a sprocket in rear and an idler in front;

The main difference, apart from the external appearance and rear shape, is propulsion. Unlike the SK 13, Wargaming’s TNH 105/1000 is not powered by a steam engine. In-game, it has two variable engines: Škoda AHK (in-game designation ‘Škoda V16 AHK-2’) and ČKD AXK (in-game designation ‘ČKD AXK proto’) 1000 hp engines, developed for the Tank všeobecného použití (TVP) project at the beginning of 1950s.

WoT’s ‘historical description’ places the TNH-105/1000 ‘development period’ to the late 1940s (probably 1947/48), when preliminary TVP designs by Škoda and ČKD were not even finished. The possibility of their engines being used for a separate project is quite low. It is the same story in regards to the chassis. A 50-tonne heavy tank with 100 mm frontal armor is unlikely to be based on an unmodified and not reinforced (as presented in-game) SK 13 hull (and, probably, any hull with Surin suspension in general). At 2.5 times heavier than the tractor’s hull, the question of technical reliability emerges.

Conclusion

The Czechoslovak program of developing a steam tractor in the interests of Germany ended in late 1944 or early 1945. By this time, two machine-building enterprises had managed to create three projects (SK 13, SK 23, and SK 33), of which only one had reached the prototype stage. Studying the SK 13 machine provided necessary experience and knowledge for further development of the concept of steam powered tractors. Nevertheless, the drastically deteriorating situation in the war for Germany contributed to the termination of the project.

Left side view 3D model of Skoda SK 13 by Phantom_25_Sniper.
Right side view 3D model of Skoda SK 13 by Phantom_25_Sniper.
Front view 3D model of Skoda SK 13 by Phantom_25_Sniper.
Rear view 3D model of Skoda SK 13 by Phantom_25_Sniper.
Top view 3D model of Skoda SK 13 by Phantom_25_Sniper.
Škoda SK 13 specifications table
Total weight, battle ready 20 tonnes
Crew 3 (commander, driver, motorman)
Propulsion 2x Škoda Sentinel steam engines (70 hp at 250 rpm)
Suspension Surin-type, leaf springs
Performance 12-15 km/h (7-9 mph)
Hull Armor 8 – 60 mm

Sources

https://www.valka.cz/topic/view/79671
https://www.valka.cz/topic/view/253870
https://www.valka.cz/topic/view/253871
Ivo Pejčoch.’Československé Pásové Dělostřelecké Tahače, 1918-1950’;
‘The Oil and Gas Journal’, Vol. 38, Iss. 17 (September 7th, 1939);
‘The Oil and Gas Journal’, Vol. 38, Iss. 18 (September 14th, 1939);
https://shusharmor.livejournal.com/656677.html
https://topwar.ru/92719-proekt-parovogo-gusenichnogo-tyagacha-dampfschlepper-chehoslovakiya.html;
http://www.sentinel.cz/;
http://www.drewnozamiastbenzyny.pl/gaz-drzewny-definicja/
https://tanks-encyclopedia.com/ww2/nazi_germany/gas-powered-fahrschulwanne-tanks.php;
http://samlib.ru/p/polo_m/6letvehrmacht.shtml;
https://history.ric.mil.ru/Stati/item/408834/;
https://wiki.wargaming.net/en/Tank:Czechoslovakia;

Categories
WW2 German Prototypes

3.7 cm Selbstfahrlafette L/70

 German Reich (1935)
Self-Propelled Anti-Tank Gun – 1 Prototype Built

It is well known that prior to WW2, the Germans were heavily involved in tank development. What is less known, is that they also experimented and evaluated anti-tank self-propelled vehicles, based on half-track chassis. These were intended to provide a quick anti-tank response to enemy armor formation attacks. This overall concept, while tested, was never fully developed and only a small number of prototypes were made, including the vehicle known as  3.7  cm Selbstfahrlafette L/70. While a single prototype was built, sadly, the general development of German pre-war self-propelled anti-tank half-track is poorly documented in the sources.

3.7 cm Selbstfahrlafette L/70 Source: T.L. Jentz and H.L. Doyle Panzer Tracts No.7-1 Panzerjager

History

During the early 1930s, in the Germany Military circles, the concept of using fast anti-tank vehicles that could outrun tanks was beginning to take shape. For this reason, on 20th November 1934, a program to develop and build such a vehicle was initiated. The chassis for this new self-propelled anti-tank vehicle project was to be based on a half-track. The choice to use a half-track chassis was probably based on its good overall road and off-road driving performance. While it could not fully match a tank’s off-road performance, especially on poor terrain, it still would perform better than ordinary wheeled trucks.  The overall performance that this vehicle would be able to achieve was best described in the Wa Prw (short for Waffen Prüfungsamt, the automotive design office) report called ‘Offensive Defense Against Tanks’ (Offensive Abwehr von Panzerwagen) published at the end of October 1935.

In its introductory part, it described the earlier thinking that the only weapon that could successfully stop a tank was another tank. It followed on by elaborating that this was not the case anymore, providing examples that bombers were not employed against bombers, but instead this was the job of the smaller fighter aircraft. Another example was that smaller and more maneuverable ships could cause huge damage to much larger and expensive but slow warships. The key element in defeating these threats was superior speed and maneuverability. The armor came in second place, and only to a limited extent, not to hinder the performance of the overall mobility.

If these factors would also prove to be beneficial for an anti-tank vehicle was a good question. In order to test the new concept of an anti-tank vehicle, it should fulfill several criteria including high road speed; good overall cross-country speed, similar, or when possible, superior to that of tanks; small dimensions; accurate fire while stationary; effective firing range up to 700 meters; cheap; and if possible, use components that were already in production. The last request was a bit unusual but optional. The main gun was (if possible) able to be dismounted to be used as a towed gun

The two main problems in this report indicated for this vehicle were the creation of the chassis with enough mobility, and finding a sufficiently strong weapon to fit in it. In the case of the gun, it had to have the best possible armor penetration, but the recoil had to be manageable. Quite interestingly, this report also mentioned the possibility of alternatively using some kind of unspecified rocket launcher. The benefit of this weapon is no recoil and the armor-piercing round could be replaced with large high-explosive rockets.

Ultimately, only two trial vehicles were completed and submitted for testing during the period of 1935 and 1936. One of these was the 3.7 cm Panzerabwehr-Geschütz auf Selbstfahrlafette and the other one was simply described as Tankjager (during the early 1930s, the German Army used the term tank, later being fully replaced with Panzer).

3,7 cm Selbstfahrlafette L/70

For producing one such vehicle prototype, the Wa Prw issued a military contract to two firms, each designated to produce different necessary components. The company Hansa-Lloyd was tasked with building the chassis and the company Rheinmetall-Borsig for designing and building its main weapon and a turret. It was quite common practice in Germany, prior to the war, to include a number of different manufacturer companies in one project. The German industry at that time was still undeveloped and including other companies allowed them to gain valuable experience in armored vehicle design and construction.

When the vehicle was completed, it received an unusual but simple 3,7 cm Selbstfahrlafette (self-propelled) L/70 designation. Unfortunately due to being poorly documented in the sources, not much is generally known about this vehicle. What is known is that it was completed in 1935.

Specifications

The Chassis

The 3,7 cm Selbstfahrlafette L/70 chassis was based on the HL kl3(H) half-track vehicle, developed by Hansa-Lloyd. A pre-war attempt to design a cheap and easy-to-produce half-track. This vehicle chassis could be divided into three major compartments. The front driver compartment was fully protected except for the wheels. The central firing compartment housed the main weapon. And lastly, the rear positioned engine compartment.

The Engine and the Running Gear

The 3,7 cm Selbstfahrlafette L/70 was powered by a Borgward engine, providing 70 hp @ 2,600 rpm. The engine was positioned to the rear of the chassis, somewhat unusual for German half-track vehicles. The installed transmission had 4 speeds, with a 2-speed transfer case. The maximum speed on the road was an excellent 50 km/h. While the cross-country speed is not listed in the sources it was likely slightly slower.

A view of the 3,7 cm Selbstfahrlafette L/70 engine bay. Source: www.armedconflicts.com

The torsion bar suspension consisted of one front drive sprocket, 5 road wheels, and a rear idler, larger than the wheels. Each track was 1.6 meters long. Two steering wheels were located to the front of the vehicle. These, like all German half-track designs, were not powered.

A drawing of the HL kl3(H) half-track chassis. Somewhat unusual for German half-tracks, the engine was placed to the rear. In front of it were the fuel tanks and the main gun mount base is visible. Lastly, the driver’s seat and steering wheel are in the front. Source: www.armedconflicts.com

Armored Body

On top of the chassis, a larger armored superstructure was placed. The overall armor thickness is unknown, but given the fact that it was intended to be a lightweight vehicle and easy to build, it would most likely provide protection against small-caliber bullets. The high angled armored superstructure slides also served to provide additional protection.

The front part of this armored superstructure where the driver was positioned, was provided with at least one hatch, which was placed on the right side. Sadly there is no photograph of the vehicle’s left side, but it’s highly possible that another door was also added to this side. For observing his surroundings, the driver was provided with three visor slits. The two front steering wheels were completely exposed and could be easily damaged by enemy fire. Whether this was intentional or hoped to be later covered in armored plates, given that this was only a prototype vehicle, is sadly unknown.

The driver’s interior was very cramped. The driver could see where he was going to two sides and one front visor slits. Source: www.armedconflicts.com

The center of the vehicle was provided with highly angled armor plates. These spread from the bottom towards the top. While this arrangement provided additional protection, it also provided the crew with somewhat more working space inside the vehicle. On the right side, possibly also on the left, a rectangular hatch was added, possibly to serve as an entering point for the crew but also for maintenance.

The angled armor is evident here. This helped to reduce the need for thicker armor, but complicated the overall production of this vehicle. The side rectangular hatch is noticeable here. No mudguard was provided for the tracks. Source: www.armedconflicts.com

The engine compartment had three ventilation grill hatches. One to the rear that could be opened and two on each side. Interestingly, in one photograph, these side hatches were covered by an armored plate. These probably offered a large target for the enemy and were thus replaced with simple armored cover. In addition, there was another two-part hatch placed on the top of the engine compartment.

Rear view of the 3,7 cm Selbstfahrlafette L/70 Source: www.armedconflicts.com

Turret

On top of the armored superstructure, an open-top turret was placed. Unlike a tank turret, the 3,7 cm Selbstfahrlafette L/70 turret was more like an extended armored shield of its main gun mount, somewhat similar to the later Sd. Kfz. 222 armored cars series. The front of the turret was occupied by the main gun positioned in the center. To the left of the gun was a hatch for the gun sight. A machine gun ball mount was placed on the opposite side. There were no side visor slits or hatches but given that the turret top was open, this was not needed. To the rear, a small hatch was added. It probably served to remove spent cartridges or was used for gun barrel removal. On top of the open turret, a round-shaped anti-aircraft machine gun mount was placed. The whole turret could rotate 360°.

The 3,7 cm Selbstfahrlafette L/70 armament consisted of one gun and two machine guns. The machine gun ball mount is located right of the main gun. Source: T.L. Jentz and H.L. Doyle Panzer Tracts No.7-1 Panzerjager
The turret top was completely open and exposed to elements of enemy fire from above. Source:www.armedconflicts.com

Armament

The main armament consisted of one 3.7 cm PaK L/70 anti-tank gun especially developed by Rheinmetall. It had a horizontal slide breach and was probably semi-automatic. This weapon is somewhat an enigma as very little is known about it.  What is known is that when firing an armor-piercing round, which weighed some 0.710 kg, the muzzle velocity was 900 m/s.  To the rear of the breach, a canvas bag was located to serve to catch any spent cartridges. The elevation of this weapon was -7° to +20°. The main ammunition storage bin was located behind the gun. The unusual feature of this gun was the cone-shaped muzzle brake. To improve the stability of the gun, a larger metal bar with two round cutouts was added to the rear of the gun.

A rear view of the 3,7 cm gun. Source: www.armedconflicts.com
The ammunition storage bin was placed behind the main gun. Source: www.armedconflicts.com
Side view of the 3.7 cm gun mount, with the canvas bag placed to the rear. In addition, the larger bar (with two round openings) stabilizer is also visible here. This mount also illustrates the vehicle’s overall small size, having barely enough room for it. Source: www.armedconflicts.com

The secondary armament consisted of two MG 34 7.92 mm machine guns. One was placed in the turret machine gun ball mount. The second one was placed on top of the turret in a specially designed anti-aircraft mount. No information is provided in the sources about the precise amount of ammunition for the main and secondary weapons.

The second Mg 34 was placed in a round anti-aircraft mount. Source: www.armedconflicts.com

The Crew

The number of crewmen is not mentioned in the sources. Given the vehicle’s overall small size, we can give an educated guess that it would likely consist of at least three crew members. The driver was positioned in the front driver compartment. Behind the driver’s compartment, the fighting compartment with the main gun was placed. On a few surviving photographs of this vehicle’s interior, it can be seen that two crew members were needed to operate the gun. The gunner, who was likely also the commander of the vehicle, and the loader. The gunner was positioned to the left of the gun while the loader was on the opposite side. It also appears given that both machine guns were placed on the right vehicle side and would be operated by the loader. This was far from perfect, as these two would be overburdened with more tasks than they would be able to handle. A third crew member would have greatly improved the performance of the gun operating crew, but there appears no available space for one inside the cramped fighting compartment.

Positions of the crew operating the gun, with the gunner to the left and the loader just behind him. Source: www.armedconflicts.com

Fate

According to Rheinmetall-Borsig documentation, salvaged after the war and dated from 1940, only one 3,7 cm Selbstfahrlafette L/70 vehicle was ever built. It was supposedly tested extensively prior to the war. As mentioned earlier, due to the lack of sources, the precise fate or use of this vehicle is not well documented. But the fact that only one vehicle was built gives us an indication that the design was not good enough to warrant serial production. The fate of the prototype is unknown, but it was probably scrapped during the war.

While not adopted for service, the single prototype was noted for being used for testing and evaluation. But ultimately it did not enter production. Source: www.armedconflicts.com

Conclusion

The 3,7 cm Selbstfahrlafette L/70 was a quite unusual concept developed by the Germans during the mid-1930s. It generally fulfilled a few aims of the German Army mostly regarding speed and firepower. The half-track chassis could achieve speed up to 50 km/h on roads, while the longer 3.7 cm gun likely had much better armor-piercing performance than the 3.7 cm Pak 36 that was in service at that time. The negative sides were the generally small and cramped interior, low armor thickness, use of a gun that was not in service, and that the half-track was generally not cheap for production. But the reasons why this project was rejected are sadly not available. Due to almost nonexistent sources on this unusual vehicle, we will never know its overall performance nor its reason for rejection.

3,7 cm Selbstfahrlafette L/70. Illustrations by the Octo10 funded by our Patreon Campaign.
Dimensions (l-w-h) 5.1 x 2 x 1.65 m
Total weight 6 tonnes
Crew 3 (Commander/Gunner, Driver and Loader)
Propulsion Borgward  70 hp @ 2,600 rpm
Speed 50 km/h,
Armor  Unknown but probably light
Armament 3,7 cm PaK L/70

 

Sources

 

Categories
WW2 German Prototypes

Schwerer-Flammpanzer auf Tiger I (Flammanlage auf Tiger I – ‘Flammpanzer VI’)

German Reich (1944-1945)
Flamethrower Tank – 1 Incomplete Prototype

There is something about a flamethrower that induces the primordial fear amongst those on the receiving end. The awe of seeing a sheet of flame projected towards you with little or no chance of stopping it was recognized as a very effective psychological weapon during World War I, when these devices first started to be fielded. Even as far back as then, there were ideas and plans to mount these flamethrowers into tanks. An armored all-terrain platform makes a lot of sense for a flamethrower-carrier, as it is protected by its armor from the small arms of the enemy but also able to traverse the rough or broken ground in front of the position. Further, whilst a man-portable system was limited by the ability and stamina of the man hauling it, a vehicle was not. A vehicle-mounted flamethrower system could carry far more fuel for a bigger flame thrower with a longer range than was possible with a man-portable system.

The Germans, right from World War I, were fans of flamethrowers and understood the potential of them both in their direct military application for clearing an enemy position as well as for their psychological effect. Various German tanks in World War II were trialed with flamethrowers, although some are better known than others. One of these projects that is mostly forgotten and was never realized in a vehicle was the fitting of a heavy flamethrower into the hull of a Tiger I, the Schwerer-Flammpanzer auf Tiger I.

Flamethrowers mounted on the Panzer I (Pz.Kpfw. I Ausf.A), also known as ‘Flammpanzer I’, were used in North Africa against the British and a version known as the ‘Flamingo’, based on the Panzer II (Pz.Kpfw.II(F) Sd.Kfz.122), also known as ’Flammpanzer II’, was used on the Russian Front. Both of these vehicles saw relatively limited service. They were simply too vulnerable to enemy fire with thin armor which even an anti-tank rifle could penetrate from the front. As such, the poor range of the flame projectors they mounted left them very vulnerable to being penetrated as they had to get too close. This, and carrying hundreds of liters of fuel inside the tank was thus a recipe for disaster for the crews. The Flammpanzer I had mounted its projector in the turret alongside a single machine gun but the Flammpanzer II went for two nozzles, one on each front mudguard over the tracks (Spritzkopfe – Spray Heads). Each was independently operable, able to be rotated through 180 degrees. The turret was changed to include new vision ports permitting a better view of each nozzle as it worked and just a single machine gun. Flame time for the Flammpanzer II was limited. Just 160 litres of fuel were carried, enough for up to 80 ‘shots’ lasting up to 2-3 seconds each with the usual method being to douse the target with fuel before igniting it.

Flammpanzers I and II (Flamingo) showing the turret-mounted flame-projector on the Panzer I and the front-wing mounted projectors on the Panzer II. Source: Jentz et al. (left)

A solution to the lack of armor on the Flammpanzer I and II was to use the hull of a more heavily armored tank. Whilst it was on a much slower platform, a successful flamethrower was retrofitted to captured French Renault Char B tanks (Pz.Kpfw.B2 (F1)). Powered by a J-10 Motor driving a pump rather than being reliant upon cylinders of compressed nitrogen gas as the propellant like on the Flammpanzer II, this system had a range of 40 to 45 metres with enough fuel for about 200 separate bursts. This was a new type of fitting designed by Wegmann, although the actual flamethrower was designed by Koebe. This partnership paired the heavily protected Char B hull with the flamethrower, allowing, at least in theory, for the vehicle to get close enough to the enemy to make use of it.

Two views of the front-mounted flame-projector fitted to the front of the captured French Char B2 (Pz.Kpfw.B2 (F)). Source: Jentz et al. via The Tank Museum, England

The Panzer III (Pz.Kpfw.III (F) Sd.Kfz.141/3) flamethrower version, also known as the Flammpanzer III, was different to the Pz.Kpfw.B2 (F) using a Koebe* HL II 40/40 1000/20 pump which, in turn, was driven by a two-stroke 28 hp Auto Union ZW 1101 (DKW) (1,100 cc) engine. It could achieve a jet of burning flame oil out to just 60 metres at a pressure of 1.52 to 1.72 MPa (15 to 17 atmospheres) and a rate of 7.8 litres per second. The fuel mix itself was a mixture of oil and petrol to create a thickened burning fluid which was easily ignited by means of Smits glow plugs (Smitskerzen). This system had far better mobility than the Pz.Kpfw.B2 (F) retrofitted system, but still required improvement and found limited use.

*(Koebe was the firm of Hermann Koebe Feuerwehr-Geraete-Fabrik of Berlin, a manufacturer of fire-fighting equipment)

Panzer III (Pz.Kpfw.III (F) Sd.Kfz.141/3) ‘Flammpanzer III’ in action. Source: Jentz and Doyle
Koebe HL II 40/40 1000/200 auxilliary pump and fuel tank (on top) as used in the Pz.Kpfw.III (F) to deliver the flame-fuel. source: Jentz et al.

Enter the Tiger

Despite the successful use of various flamethrower-armed vehicles, including tanks and half tracks, during the war, it was clear to the Germans that the short range of the flame systems used meant that the vehicles carrying them had to get too close to the enemy and this rendered them vulnerable to fire. The solution was twofold: first, put the flamethrower on a heavily armored platform (like had been tried on the Pz.Kpfw.B2 (F)), and secondly, partner this with a new, longer-range flamethrower system.

At the end of 1944, a solution was proffered by Hitler. On 5th December 1944, during a conference, he requested that a long-range flamethrower should be mounted behind as heavy an armored chassis as possible. Various heavy tank projects had been suggested up to and including the Maus (which had been through its own flamethrower development by this time). The Tiger II chassis was the most well armored vehicle in service which was in production at the time, but chassis for that vehicle were at a premium. The next best thing of course was the Tiger I (Sd.Kfz.181 – Tiger Ausf.E), a vehicle which had finished production and for which there were hulls available as vehicles were brought back from the front for repair.

Repurposing these hulls for this use was not dissimilar from the idea to reuse hulls for the Sturmtiger programme, as it meant that a tank which might have had severe and irreparable turret damage could be reused for the war effort. Unlike the Sturmtiger though, this flamethrower idea would not require extensive rebuilding with a new superstructure and weapon system. Instead, the plan was much simpler. Hitler’s goal was a Flammpanzer with frontal armor which was impenetrable to enemy fire with a target of 250 mm, but the Tiger I, with armor up to 120 mm thick on the front, would have to do in the short-term. This demand was repeated by Hitler on 29th December 1944 and the task passed over to Obert Crohn of the Entwicklungskommission Panzer (Tank Development Committee).

Preserved Tiger 131 at The Tank Museum Bovington. Currently the only running Tiger tank in the world. Source: Mark Nash

Development

Reusing Tiger I hulls would mean there would be no need to design a chassis on which to mount this flamethrower but there were still technical hurdles to overcome. First was the flame-part of the problem and, on 23rd January, Obert Crohn reported a solution. It was a reversion to the older high-pressure gas-based delivery system but it would provide a significantly longer range flamethrower, at 120-140 metres. The mounting for the weapon was selected as being the machine gun port on the front of the Tiger, meaning it could be directed by the man in the front right who had previously had the role of radio operator/hull machine gunner, but there was still the issue of the fuel tanks. The interior of the Tiger was crammed full already with the equipment it needed to function as a tank as well as the turret basket, ammunition etc., so there were only two easy options for the fuel. Either it would have to be hauled in a trailer behind (a solution adopted famously by the Churchill Crocodile) or else the turret would have to be removed to create the space. The advantage of a trailer idea is that the main gun could be retained, but this would come at a cost. The trailer would be vulnerable and, since the surplus Tiger Is were those with damaged turrets anyway, the turretless internal-fuel-stowage option was chosen instead. This would be lighter and avoid the vulnerable trailer but had its own flaws. First was the lack of armament as the hull weapon had been replaced, and the turret weapons had been lost. This would receive separate consideration for a solution. The second problem was the profile. A turretless Tiger would draw significant attention and be an obvious target on which an enemy could focus fire.

Certainly, production would not have been a significant issue as the modifications were modest but the whole concept had to be called into question. Major General Thomale was a fan of the flamethrower but only in limited circumstances. Specifically, he liked them on small, light, and maneuverable vehicles which could target the odd stubborn strongpoint and the Tiger I was neither small, light, nor particularly fast even with a turret removed. His second point was also valid. With its main gun, the tank could pick off the enemy at combat ranges up to 2,500 metres meaning a significant safety distance from their fire and, with 80 rounds, could do so many times. A flamethrower meant getting very, very close and offered relatively few attempts to destroy the enemy. Despite the limited advantages of the system, he was therefore against it.

The flame thrower system designed could still be used, but would have to be mounted on something smaller and lighter instead, and the Jagdpanzer 38 was selected as the replacement. Nonetheless, the idea of a flamethrower on the Tiger I was not over.

On 19th March 1945, despite the extremely dire war situation, the project, named ‘Flammenlage auf Tiger I’ (Flame mounting on Tiger I) or ‘Schwerer-Flammpanzer auf Tiger I’ (Heavy flamethrower on Tiger I) was still being listed as a project under development and Hitler ordered Maj.Gen. Thomale to fit the flamethrower system to a turretless Tiger I with the second idea of increasing the thickness of the armor on the front. Quite how much additional armor was meant to be added is not clear nor how it was to be done, but perhaps something akin to the method used on the Ferdinand/Elephant is the best approximation as to which would have been adopted. The Sturmtiger was similarly up-armored with an extra 50 mm plate, which suggests the frontal armour of the Schwerer-Flammpanzer auf Tiger I could have been increased to around 150 mm across the front, a lot less than Hitler might have wanted but certainly a significant improvement.

The original Tiger (P) armor was significantly improved with heavy armor plating bolted to the original front to improve protection. Source: Jentz and McKaughan
Prototype Sturmtiger with 50 mm thick additional front armor plate bolted on the lower front section.

Further progress was still reported into the final days of Nazi Germany, with an update from Wa Pruef 6 on the project as late as 3rd April 1945. In this report, Obert Holzhauer (head of Wa Pruef 6) reported that, following Hitler’s orders, the first steps in putting together this experimental heavy flamethrower on a Tiger I had taken place at Wegmann, Kassel on 21st and 22nd March with completion of the project estimated by 15th April. The Tiger I to be used had been dispatched by train from Kummersdorf on 17th March but, due to enemy bombing, had been delayed until 3rd April 1945. From Kassel, the vehicle was then sent to the firm of MIAG at Braunschweig for assembly there under supervision of men from Wegmann.

This additional movement and Allied bombing meant that the target completion date of 15th April was missed and the vehicle was never completed. Likely, work on actually fitting the system was never even started before Allied forces overran the facility. This is confirmed by a British intelligence report of the time which stated:

…It is believed that this equipment never progressed beyond the experimental stage and no specimen has yet been recovered….

– War Office. (26th July 1945). Technical Intelligence Summary Report 182 Appendix F ‘Flame thrower mounted on Pz.Kpfw. TIGER MODEL E (Sd.Kfz.181)’

System

The new flame-system that was to be fitted to the Flammenlage auf Tiger I reverted back to using compressed nitrogen and special reduction valves (obtained from the Kriegsmarine) which raised the pressure output from the tanks. This meant that this new system had abandoned the motor-driven-pump system. In this way, the pressure of the system could be raised from 1.52 to 1.72 MPa (15 to 17 atmospheres) to 2.03 to 2.53 MPa (20 to 25 atmospheres). With this increased pressure, the system could deliver a jet of burning fuel out to a range of 120 to 140 metres. A pair of 400-litre fuel tanks* would be fitted on the inside (there was more room because no turret was required), providing enough fuel for 16 to 20 bursts, meaning each burst would use about 40 to 50 litres of fuel. At 2-3 seconds per burst, this means the system delivered about 20 litres per second.

The fuel was different to what had been used before. Koebe, when asked at the end of 1942 to design a long-range flamethrower for use on the Porsche-Maus, proved unable to develop a system with a range of more than 100 m. Even then it would have required a flame-nozzle (Spritzkopf) 22 mm wide and would have used 33 litres 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 the jet would disperse with range. To go further, therefore, the fuel needed to be thicker and it was this factor which meant a pump could not be used. Even with a range of 140 metres, this was still not ideal and Hiter, in March 1945, still wanted a thicker fuel to match the type used by the British on their flamethrowers, but there would be no time to develop an even thicker fuel. The projector itself, when fitted into the front of the Tiger, would have had only limited traverse. A range of motion of just 10 degrees in all directions was possible.

*(A British report from July 1945 on the project reported a single 300 litre tank, suggesting just a single fuel tank was found with the remains of the system when it was recovered and mis-estimated in volume)

Given that this project was relatively crude, it is hard to know exactly how many men would have been required to crew it, but some things are known. For example, the tank would have had to have kept its driver, located in the front left. Without any kind of remote-control over the direction of the flame-projector, the flame-projector located in the front right would need manual operation too and this would have meant the retention of the man who would usually operate both the hull machine gun and the radio. He would have been the flame-operator and likely still the radio operator too, although it was also identified that flamethrower tanks should have a second radio set in order to coordinate with supporting vehicles. This would suggest the use of a Panzerbefehlswagen Tiger hull which was fitted with both a Fu 5 and Fu 8 (Sd.Kfz.267) or Fu 7 (Sd.Kfz.268) radio sets, although on the Panzerbefehlswagen Tiger the additional set was fitted into the turret and would have to be relocated within the hull. No loader was required nor was a gunner, but a commander would certainly have had to be retained in order to coordinate the operation of the vehicle, which would therefore indicate a crew of 3 men. Even with the removal of the turret and ammunition, the two 400-litre tanks required would have taken up a lot of the internal space and it is doubtful there would be room for a fourth man and, in any case, there was no clear role for him anyway.

Automotive

As the vehicle was based upon an existing Tiger I hull, there were likely no changes made to whichever hull was to be used. As the Tiger I had gone through production, various minor changes were made to some internal and external fittings. Some were fitted with special air filters at the back, and others not. Early production Tiger I vehicles received the 650 hp Maybach HL 210 650 hp petrol engine whilst later vehicles received the 700 hp Maybach HL 230 petrol engine. Early production Tigers used rubber-tyred road wheels but these were later replaced with a more resilient steel-tyred type. Without knowing which hull was to be used, it is impossible to know exactly what the Schwerer-Flammpanzer auf Tiger I would have looked like, but the essentials of the automotive system would be identical.

Layout

Changes to the Tiger I hull were relatively modest. Removal of the turret meant leaving a large hole in the roof of the tank which was obviously a serious hazard in combat so this would have been covered with a large armor-plate. Already discussed is the additional armor on the front, although how this might have looked around the machine gun mounting is unclear. Other than these changes and the interior changes, like the removal of the ammunition racks etc., there would have been few changes inside and most of the work would have been done on the roof. For the prototype, it is possible that just a single plain disc of metal welded or bolted over the hole where the turret would have sat would have been employed. This would have retained the front crew hatches but meant that a commander in the back would have been unable to get out except by these front hatches. Given the hundreds of litres of fuel he would be sat next to, this seems highly improbable for any design which would ever have been authorised for production and the description in the British 1945 report provides an additional clue.

Other Armament

Whilst with no turret and hull machine gun the vehicle might seem otherwise unarmed, it was to get a new machine gun, most likely either an M.G.34 (Maschinengewehr 34) or M.G. 42. This would not have been mounted within the vehicle, but this time mounted externally. This would have been controlled from inside, again supporting the proposition of a third crew member, and would have been mounted on the outside of the cover plate over the turret-hole.

The mounting of such a weapon was certainly not a new idea and was mounted on various Sturmgeschütz in the form of a 7.92 mm M.G. 34, fitted with a 50-round drum mounted behind a short and sharply curved gun shield. Under the gun was a small optical sight which permitted the man below the armor to see where he was firing. Reloading however, had to take place externally.

Roof-mounted remote-controlled weapon station as featured on a Jg.Pz.38t (left) and from an Allied Intelligence Bulletin (right). Source: pzfahrer.net/hetzermgs.html and Intelligence Bulletin May 1945

In order to provide any value to the commander, he would have needed to be provided with some optics as the small optic on even the roof-mounted machine gun would be wholly inadequate for the purposes of command. A hatch would also have been required for observations, access or egress to the vehicle, changing barrels, or reloading/clearing stoppage on the machine gun. Despite the description of the “single continuous roof plate”, it would appear that any development of this vehicle would have needed to include at least a moveable optic and hatch for him, or even just a repurposed tank cupola.

One extra piece to consider is that the Tiger was fitted with a self-protection system launching S-mines to protect against enemy infantry. As this Schwerer-Flammpanzer auf Tiger I was, by definition, having to get very close to the enemy in order to use its primary weapon, it would be logical to assume that this type of system would have been adopted for any production of the Schwerer-Flammpanzer auf Tiger I even if the prototype being assembled did not have them. Further, a lot of flame throwing vehicles used by the Germans carried smoke-candle launchers in order to create a smoke screen to protect them from enemy observation. Here again, the addition of smoke grenade launchers on the Schwerer-Flammenpanzer auf Tiger I is a very reasonable assumption as once it had ‘flamed’ its target it would need to withdraw and a smoke screen provides ideal screening during such a manoeuvre.

Conclusion

The overall idea was not a bad one. A flamethrower certainly had some practical military value and served as a potentially very effective psychological weapon against the enemy too. This fact was reinforced in February 1944 by considerations from Panzer Grenadier Division ‘Grossdeutschland’, which recommended the use of a motor-driven ‘howling siren’ to accompany the use of the flamethrower to maximise the demoralisation effect.

Early flame-throwing attempts had been too small (Panzer I), too lightly armored (Panzer II) and too short in range (Panzer III et al.). A heavy flamethrower paired with a heavily armored hull from the Tiger I seems like a system which could have fulfilled the requirements but it was simply flawed in premise.

With very little development time on hand and with the progress of the war going so badly, this was a weapon system which was not going to enter production. The days of assaults against fixed enemy positions like bunkers and trenches, for which a flamethrower is best suited, were over by 1945, as most of the fighting was defensive in nature. The Schwerer-Flammpanzer auf Tiger I was never finished so no photos of it exist and whatever plans may have existed for it are believed to have been lost. Outside of reports, both German and British, the project remains unknown, and the reader is therefore reminded that the discussion over the vehicle is speculative, as is the artist’s rendering.



Illustration of the Schwerer-Flammpanzer auf Tiger I (Flammanlage auf Tiger I – ‘Flammpanzer VI’’) based on existing descriptions. Modified by Pavel Alexe, based on wok by David Bocquelet.

Sources

Doyle, H., Jentz, T., Sarson, P. (1995). Flammpanzer German Flamethrowers 1941-45, Osprey Publishing, UK
Doyle, H., Jentz, T. (2011). Panzerkampfwagen III Umbau. Panzer Tracts, Maryland, USA
Jentz, T., McKaughan, J. (1995). Elefant Panzerjager Tiger (P). Darlington Productions, Maryland, USA
Jentz, T., Doyle, H. (2008). Panzer Tracts No.6-3 Schwere Panzerkampfwagen Maus and E 100.
US War Department. (May 1945). Intelligence Bulletin Vol. III No.9. War Department, Washington, USA
War Office. (26th July 1945). Technical Intelligence Summary Report 182 Appendix F


Categories
WW2 German Prototypes

Schwerer-Flammpanzer auf Jagdtiger (Flammanlage auf Jagdtiger)

German Reich (1944-1945)
Flamethrower Tank – Design Only

The Germans were quick to exploit the devastating psychological effects of the flamethrower in the First World War with man-portable examples. Those were short-range devices that excelled at demoralizing the enemy and at clearing enemy positions. However, they were seriously limited by their weight, range and operational endurance for ‘flaming’ – a function of how much fuel it could carry. There is only so much a man can carry and, even in WW1, there were ideas for mounting flamethrowers onto armored vehicles. Armor would allow for close contact with the enemy to obviate the problem of range, the engine and platform would counter the flaw of a man not being to carry enough fuel, and the armor would ensure it was protected, unlike a man-portable version. In WW2, the Germans tried various vehicles as the mounts for flamethrowers, from the Panzer I and II up to and including the Tiger I. One of the lesser-known concepts though was the consideration of the Jagdtiger as the platform on which to mount a flamethrower.

Why the Jagdtiger?

It is hard to understand quite why the Jagdtiger was considered as a possible platform for a heavy flamethrower without a short review of the previous flamethrowing equipment operated by the German Army. Some Panzer I’s were modified to mount flamethrowers during the Spanish Civil War, and very early in World War II the Germans had mounted a man-portable flamethrower into the turret of a Panzer I (Pz.Kpfw. I Ausf.A), known as ‘Flammpanzer I’. These had been used in North Africa against the British but the very thin armor of the Panzer I left it vulnerable close-up to anti-tank rifle fire and even concentrated machine-gun fire. The short-range of the man-portable flamethrower and small fuel tank meant that not only did it have to get very close to be effective, but also had a very short flame time on target due to the small fuel capacity.

Flammpanzers I and II (Flamingo) showing the turret-mounted flame-projector on the Pz.1 and the front-wing mounted projectors on the Pz.2 Source: Jentz et al. (left)

An improvement in this regard was the Pz.Kpfw.II(f) also known as ’Flammpanzer II’, which found use on the Russian Front. Slightly improved in all regards, the Flammpanzer II was still vulnerable to enemy fire and had an inadequate flame duration and range. It would not be until the retrofitting of a motor-driven flame-throwing system on captured French Renault Char B1 heavy tanks that at least one of these concerns (the armor issue) was resolved. That vehicle, known as the Pz.Kpfw.B2 (fl), had abandoned the compressed gas cylinders used on the Pz.Kpfw.II(f) and adopted a motor-driven pump to provide the pressure required, using the same principle as a fire-fighting pump for projecting water. Although this did require a relatively low-viscosity flame fuel made from oil mixed with petrol, the pump was able to cope and propel burning fuel out to 40 to 45 metres. The drawback with mounting this system on the Char B though was obvious. It was a captured vehicle in limited supply, was also rather slow and, more importantly, did not provide a significant increase in range.

Two views of the front-mounted flame-projector fitted to the front of the captured French Char B1 (Pz.Kpfw.B2 (f)). Source: Jentz et al. via The Tank Museum, England

It was not until the Pz.Kpfw.III (fl), a flamethrowing tank based on the Panzer III, that an effective German flame tank was provided. Powered by a Koebe* HL II 40/40 1000/20 pump which, in turn, was driven by a two-stroke 28 hp Auto Union ZW 1101 (DKW) (1,100 cc) engine, the Pz.Kpfw.III(fl) could propel a jet of burning flame oil out to just 60 metres at a pressure of 1.52 to 1.72 MPa (15 to 17 atmospheres) and a rate of 7.8 litres per second. The fuel mix itself easily ignited by means of Smits’ glow plugs (Smitskerzen). Mounting this weapon on the Panzer III provided adequate armor and mobility. It was still not ideal however, and would only find limited use.

* Koebe was the firm of Hermann Koebe Feuerwehr-Geraete-Fabrik of Berlin, a manufacturer of fire-fighting equipment

Pz.Kpfw.III (F) Sd.Kfz.141/3 ‘Flammpanzer III’ in action. Source: Jentz and Doyle

Flammtiger

The obvious successor to the Panzer III as a carrier for flamethrowing equipment was not, as might have been expected, the Panzer IV, because the same faults found with the Panzer III were still there on the Panzer IV, most importantly a lack of sufficient armor. The range of the weapon guaranteed that any vehicle had to come to very close range with the enemy which left it vulnerable, especially on the flanks, to enemy fire. This was why heavy/assault tanks carried heavy armor and it is no surprise therefore that, for an assault flamethrower, protection could be provided in two ways. Firstly, by increasing the distance from tank to target – which meant a longer range flamethrower, and secondly, by increasing the armor on the tank itself. By the time this was being considered though, the Allies were already operating heavily-armored flamethrowing vehicles with a long range, such as the Churchill Crocodile. With up to 152 mm of frontal armor, a range of 140 m and carrying nearly 2,000 litres of flame fuel, the Churchill Crocodile was strides ahead of anything in the German inventory and should have come as absolutely no surprise to the Germans. They had, after all, captured some Churchill Oke flamethrower tanks after the raid on Dieppe in 1942, yet had done little work on the subject.

It was not until 5th December 1944 that proper consideration was given to a long-range, good-duration, heavy flamethrower on a well-armored chassis, when the topic came up in a conference with Hitler. Hitler was no stranger to the idea. He had, after all, pressed for the addition of not one, but two flame nozzles to be added to the Porsche Maus over a year earlier, pushing for a system with a range of 200 m. By the end of 1944, though, the Maus project was effectively over despite having a functional vehicle, there was no prospect of production restarting for it. The most heavily armored chassis in use and available at that time was that of the Tiger II. Tiger II hulls were at a premium at the time and production was focussed on both the tank version of the hull as well as the tank-destroyer version, known as the Jagdtiger, with the huge 12.8 cm gun.

Hitler’s goal was to put a heavy flamethrower onto a vehicle with enough frontal armor to be effectively immune to enemy fire and this meant very thick armor. This was the focus of the following meeting on 29th December 1944 and the heaviest armored vehicle available was the Jadgtiger, but only if a range of 200 m could be achieved, something which at the time could not be done.

Despite a following meeting on 3rd January 1945, where the extremely heavy armor was emphasized and that a figure of 250 mm was needed (the same as the front of the Jagdtiger’s casemate), more discussion was had but no designs or plans were forthcoming. The Jagdtiger, as it met the armor requirement, was the leading prospect for this new vehicle, even if those vehicles were at a premium and needed for their original role.

At a further meeting held on 23rd January 1945 by the Entwicklungskommission (tank development committee), Obert Crohn of Wa Pruf 6 presented a design for a new flamethrower. This design, like the Churchill Crocodile, used compressed nitrogen gas (going back to the original gas-propelled rather than motor-driven system) and could achieve the same range as that of the Crocodile, about 140 metres. How much the Crocodile system influenced that design is debatable although the similarities are interesting.

With this new system designed, a longer range was achievable, albeit not the 200 m demanded and with Jagdtigers in short supply, it was instead to create a prototype based upon the hull of a Tiger I Ausf E. Whether that Tiger I-based heavy flamethrower would ever have been developed further into an actual production vehicle on the chassis is unknown, just as is whether or not the Jagdtiger-based idea would be revised if the flamethrower had proven successful. As it was, neither project was ever built. The Tiger I-based system was ordered and parts sent for assembly, but the war ended before this had been assembled. Nonetheless, a concept of what a production version of that Tiger I-based vehicle could look like is possible.

The Tiger I-based option was worked on under the name Schwerer-Flammpanzer auf Tiger I’ (Heavy flamethrower on Tiger I), so the Jagdtiger-based option could be speculatively referred to as Schwerer-Flammpanzer auf Jagdtiger’ (heavy flamethrower on Jagdtiger).

Schwerer-Flammpanzer auf Jagdtiger: What Would it Look Like?

Knowing only that the Jagdtiger platform was considered for mounting this heavy flamethrower system, and there being no plans or drawings known to exist for it, it is not possible to know exactly what such a vehicle could have looked like had it ever been built.

An examination of the considerations at play during this period provides some important clues though. First is the gun, not the flamethrower nozzle but the actual gun on the Jagdtiger. This gun was a 12.8 cm Pak.44 L/55. A very potent gun capable of firing a 28.3 kg armor-piercing shell and penetrating around 200 mm of armor at a range of 2,000 m. The obvious desire for the Jagdtiger would be to retain this gun as it allowed for the destruction of the enemy at a very long-range rather than closing to close range for a flame-attack. Major-General Thomale, for example, understood the value of flamethrowers, especially those on small, light and maneuverable vehicles and bemoaned the idea of a flame system on a Tiger I as it was wasteful of the main gun.

That obvious advantage of keeping the main gun was fulfilled by the British on the Churchill Crocodile and exactly this consideration was given the Tiger I project – retain the gun and add a flamethrower.

Taking the Jagdtiger therefore, exactly the same consideration can be given to it. Retain the gun and add the flamethrower in place of the hull machine gun. This, on the face of it, gained the advantages of both ideas but had a couple of flaws. Firstly, the loss of the machine gun would leave the Jadgtiger with no secondary armament, as it did not have a coaxial machine gun like the Tiger I. Of course, for the Tiger I option, it was eventually selected to go without a turret anyway, so it was left in the same boat and to get around this problem a remote-controlled machine gun was fitted to the roof of the Tiger I hull. Conceivably, a machine gun could easily be added to the roof of the Jagdtiger too as it retained all of the usual features there.

The second problem of putting the flamethrower in the hull machine gun position and retaining the gun was space. There was simply no space inside the Jagdtiger in which to put the large-volume fuel tanks required of a flamethrower. The same problem had been considered on the Tiger I (with turret) and the same solution was apparent for both. The obvious route was the same one taken by the British, the towing of a fuel-carrying trailer. For the Crocodile, the nitrogen cylinders were fitted into the trailer along with the fuel and then it was piped through the tank to the nozzle at the front for projection. The trailer-option, however, was not adopted, perhaps because it was too vulnerable to fire or for want of developing a whole new trailer for it.

With no trailer option possible, this would leave a question as to where the flamethrower would be mounted. It could, of course, go in the hull replacing the machine gun, perhaps retaining a dummy barrel, but it could likewise have simply, and more effectively, been mounted inside the huge casemate. The massive mounting at the front which allowed the 12.8 cm gun to move could be repurposed for holding the flame nozzle, as this would be easy for the gunner (to the left) to operate and direct whilst at the same time retaining the existing machine gun for close defence. In the absence of any plans or any development of the Jagdtiger-based idea, it is not possible to know which of these might have been selected.

Jagdtiger damaged during a bombing raid on the Nibelungen works on 16th October 1944 affording a unique look inside showing the enormous interior of the casemete to be occupied by the 12.8 cm gun. Source: Frohlich and Schneider respectively

The one thing the Jagdtiger really offered, making it a good choice for this heavy flamethrower idea, was volume, it was simply huge inside. With the breech, mounting, and ammunition for the 12.8 cm removed, there would easily have been enough room for fuel tanks. For the Tiger I, for comparative purposes, it was to have its turret removed and still had space for a pair of 400 litre fuel tanks. Retaining its full interior volume, a Jagdtiger-based vehicle would have had even more space inside so more than 800 litres could easily have been carried. Any further speculation as to what a potential Schwerst-Flammpanzer auf Jagdtiger is perhaps best left to model makers.

System

The new flame-system which had been chosen is worthy of attention in any discussion over this potential vehicle. As previously stated, the system had gone back to using compressed nitrogen gas, and was to use special high-pressure fittings to raise the pressure available from them. The reason for going back to gas-propellant was a change in fuel. In order to reduce dispersion and in an attempt to get closer to the thickened mix used by the British, the old oil/petrol mix had to be thickened up and this meant that a pump could no longer be used. The system pressure on the Pz.Kpfw.III (f) operated at 1.52 to 1.72 MPa (15 to 17 atmospheres), and by changing to this high-pressure gas system, that was increased to 2.03 to 2.53 MPa (20 to 25 atmospheres). This, and the thicker fuel, meant the range was increased to about 140 metres with a burst delivering around 20 litres of fuel per second.

Crew

Given that this project received nothing more than some consideration with no plans, it is not possible to know how many of the original complement of 6 men (commander, gunner, loader x 2, driver, and radio operator) would be retained. Certainly, the tank, at a minimum, required the driver, radio operator and commander, and with no gun, did not need the 2 loaders. This means that at least 3 men would be needed, but the gunner is questionable depending on whether or not the flame unit was mounted in the hull or casemate. Assuming it would have been casemate mounted, the retention of the gunner would have allowed the commander to concentrate on commanding the tank whilst the gunner used the flame gun to immolate the target.

Automotive

As the vehicle was based upon an existing Jagdtiger hull, there were likely no changes made to the hull, save for whatever new armored cover arrangement might have been added around the casemate front around the flame nozzle. It would have retained the same running gear and the same 700 hp Maybach HL230 petrol engine with performance probably about the same, as if the large and heavy 12.8 cm gun was removed, it would simply be replaced with a couple of large fuel tanks instead.

Conclusion

The overall idea was not a bad one considering the goal was the production of a very heavily armored heavy flamethrower. Despite General Thomale’s preference for small and light flamethrowing vehicles, the use of them was limited to isolated enemy positions, as they were simply too vulnerable to enemy fire otherwise. A flamethrower on a Jagdtiger might sound incredible on paper, but the slow nature of the vehicle, the sheer size and removing the gun would have made it a very obvious target for enemy fire.

It is undoubtedly true that a flamethrower has some practical military value as well as making a huge psychological impact on an enemy force. This fact is reinforced by consideration in February 1944 from the Panzer Grenadier Division ‘Grossdeutschland’, which recommended the use of a motor-driven ‘howling siren’ to accompany the use of the flamethrower to maximise the demoralisation effect.

Regardless of whatever value such a system might have had for extensive flaming of a heavily defended enemy target, this was simply neither what the German Army needed in 1945, nor a type of combat they were undertaking. By this time in the war, it was a process of defensive combat and withdrawal. The Jagdtiger itself proved to be rather inadequate at its role despite the otherwise impressive armor and armament and reusing this chassis for a flamethrower was a project without a purpose. Such things were only pursued because Hitler had said so.

No Schwerer-Flammpanzer auf Jagdtiger was ever made or likely even drawn, but consideration of the chassis for this type of weapon system provides a special insight into both the functioning and the dysfunction at the top of German military command and vehicle design.



Jagdtiger with the main gun removed and replaced with a fake main gun to disguise the flame projector. No drawings of what a Flammjagdtiger could look like exist. Therefore the art is an impression only of what a casemate-based flamethrower might have looked like if it had ever been pursued.


No drawings of what a Flammjagdtiger could look like exist. Therefore the art is an impression only what a hull-mounted flamethrower might have looked like, in this case having to haul a trailer for additional fuel.

These illustrations were produced by Mr. C. Ryan, funded by our Patreon Campaign.

Specifications

Total weight, battle-ready >70 tonnes
Crew 4 ((Driver, Radio operator/hull machine gunner, Commander, Gunner)
Propulsion Maybach HL230 P30 TRM 700 hp Petrol engine
Speed 38 km/h (road)
Armament Heavy flamethrower – 140 m range
Armor Glacis 150 mm at 50 deg., lower front hull 100 mm at 50 deg., front hull roof 50 mm, casemate roof 40 mm, engine deck 40 mm, hull lower sides 80 mm vertical, hull upper and casemate 80 mm at 25 deg., casemate front 250 mm at 15 deg., casemate rear 80 mm at 5 deg. Hull rear 80 mm at 30 deg., front hull floor 40 mm, rear hull floor 25 mm

Source

British Intelligence Objectives Sub-Committee. (1945). BIOS report 1343: German Steel Armour Piercing Projectiles and Theory of Penetration. Technical Information and Documents Unit, London.
Chamberlain, P., Doyle, H. (1993). Encyclopedia of German Tanks of World War Two. Arms and Armour Press.
Doyle, H., Jentz, T., Sarson, P. (1995). Flammpanzer German Flamethrowers 1941-45, Osprey Publishing, UK
Doyle, H., Jentz, T. (2011). Panzerkampfwagen III Umbau. Panzer Tracts, Maryland, USA
Jentz, T., McKaughan, J. (1995). Elefant Panzerjager Tiger (P). Darlington Productions, Maryland, USA
Frohlich, M. (2015). Schwere Panzer der Wehrmacht. Motorbuch Verlag, Germany
Jentz, T., Doyle, H. (2008). Panzer Tracts No.6-3 Schwere Panzerkampfwagen Maus and E 100.
Schneider, W. (1986). Rarities of the Tiger family: Elephant, Jagdtiger, Sturmtiger. Schiffer Publishing, PA, USA
Spielberger, W., Doyle, H., Jentz, T. (2007). Heavy Jagdpanzer: Development, Production, Operations. Schiffer Military History, PA, USA
US War Department. (May 1945). Intelligence Bulletin Vol. III No.9. War Department, Washington, USA
War Office. (26th July 1945). Technical Intelligence Summary Report 182 Appendix F

Categories
WW2 German Prototypes

Demag D II ‘Liliput’

German Reich (1934-1936)
Half-Track – At Least 3 Built

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

Mahlkuch Armored Cover

German Reich (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