Porsche Volksschlepper

by Phil Carney, Don Chew, Roland Lohnert

Funding the Volksschlepper

Professor Porsche had a longtime interest in farming equipment. One of his early passions, at a time when agriculture consumed a large portion of most European lives, was to build a farm tractor to replace horses and oxen. His first tractor endeavor was in 1914 when he used his newly developed “Power House” military tractor to plow the fields at Austro-Daimler. After the formation of the first Porsche company in Stuttgart the earliest opportunity to develop a Porsche tractor project, Type 110, came in 1937. Supposedly it owes its existence to Adolf Hitler who declared, “Why not a cheap, mass-produced tractor? A sort of Volkswagen for the fields of Germany.” In retrospect, the Professor may have sold this idea to Hitler like he sold so many of his other ideas.

In his notebook, Ferdinand recorded the following specifications, “Tractors must have a low purchase price. Secondly, they must have low maintenance cost. Thirdly, they must be of universal application in agriculture. Sturdy, powerful and foolproof…” Design studies and engineering development on a Volkspflug or people’s plow began in November 24, 1937, and continued into the next year. The Type 110 was first documented in operation in January 1939 photographs, and in all, seven variants of the design were produced. Research was done in cooperation with the Agriculture School in Hohenheim, where Porsche engineers conducted many experiments with different engines types and sizes, different gearing and different fittings of farm equipment attachments. Some versions had a V-type engine, others had inline vertical cylinders, some were two cycle and others four stroke. Shortly after it was tested on the farms around Stuttgart, the one-cylinder engine went by the wayside due to a lack of power.

Type 111 expanded on the previous Type 110 design work and used a two-cylinder power plant. The earliest machines had a simple frame with the operator and controls located forward of the engine. The configuration was actually a mid-ship engine design with a transmission differential housing aft and under. The Porsche engineers thought the farmer should have a box or tray to carry tools or implements to the field. This greatly influenced tractor layout and as a result several variants evolved because of this. In all, six configurations of the Type 111 were to be tried. One interesting feature frequently seen on the Type 111 owes its existence to the rainy season which is quite common in Europe and which causes farm fields to become extremely muddy. When Porsche was employed at Austro-Daimler, he was unable to arrive at a solution for dealing with traction in mud. According to von Frankenberg, Porsche offered a 500 kronen reward to any Daimler engineer that could solve this problem. Many tried but it was Karl Rabe that finally arrived at a simple, effective solution: steel swing-out lugs incorporated onto the rear wheels. Porsche’s congratulations to him were typically Porsche. Pay him, he said. Rabe’s swing-out lugs were commonly seen into the late 1940s when more powerful engines and an engine-forward configuration negated their use. The Type 112 was the first example of a stronger engine with the 1940 appearance of the Type 112/5 being heralded as the best of the designs.

As early as 1912, Ferdinand Porsche was evaluating Austro Daimlers military products for possible use in the farm fields of Germany. In left photograph of the M12, Porsche's children, Ferry and Louise, can be seen standing on the fenders of the second tractor from the right. In the right photograph, Ferdinand Porsche is at the steering wheel of a 1916 Austro Daimler tractor known as "the Giant." (All photographs from Porsche archive courtesy of Don Chew unless otherwise credited.)

Hitler intended Volksschlepper development to follow much the same course as the Volkswagen. Hitler had appointed Robert Ley to oversee bringing the VW into production and Ley had succeeded wonderfully in the Führer’s eyes. So, Ley was commanded to provide another manufacturing plan, this time for Hitler’s Schlepper. Again Ley orchestrated a grand production scheme. The Volksschlepper factory was to be built at Waldbröl (Ley’s home town) and tractor production was set initially at 100,000 units per year increasing quickly to 300,000 per year. The German government approved financing in 1938, and architecture design for the plant was well along by 1940. Dr. Porsche and his son in law Anton Piëch worked on factory layout along with other engineers into 1942. Most probably because of higher priority wartime demands, construction lagged far behind the projected schedule and little was accomplished beyond rough site preparation. As 1944 approached, work on the Waldbröl Volksschlepper factory came to a halt, never to be resurrected.

A factor that began to influence development of a German people’s tractor as early as 1941 was the shortage of petroleum products such as gasoline, diesel fuel, and bottled gas. So work was started on a Type 158 Holzvergaser generator. A Holzvergaser is a one or two stage generator that consumes coal (one stage) or wood products (two stage) to produce gases that can be used to power internal combustion engines. Coal/wood-gas generators were applied to a wide variety of test tractors, VW and military products. In all likelihood, if it were not for the work in this area, Porsche tractor design studies would probably have come to a halt during the war due to a lack of fuel. Holzvergaser development would continue from the late Stuttgart war years to Gmünd power plant experiments with wood, peat moss, charcoal, anthracite and soft coal.

An interesting innovation in Porsche tractors dates back prior to 1938 when the Porsche engineers were cautioned “farmers will burn out clutches as they were not mechanical people.” This statement was an over simplification of the situation. In his autobiography, Ferry implies that the problem was more an issue of the intended use of the machine rather than a lack of driver skills. “We had to consider the many uses for which the machine was intended. Plowing meant one speed, harrowing another, mowing yet another and so on. There was no point in racing the engine on jobs where low rpm was sufficient. It can be seen from these requirements that, obviously, a farmer’s tractor has to be both versatile and adaptable.” So Porsche engineers gave the matter serious thought and introduced a fluid coupling between the flywheel and the dry disc clutch. Porsche commissioned Voith to develop this fluid coupler based on Voith's existing design used in marine applications. This coupler proved to be both simple and trouble free. The technology was years ahead of other tractor designs. An interesting extension of the Voith coupling was the Porsche-Diesel tractor HydroStop attachment introduced in 1958. It allowed the tractor to be started, steered and stopped with the driver off the tractor and was an accessory available throughout the tractors remaining life.

In 1937, Hitler provided Porsche with money to begin design of a Volkspflug or people's plow. Known by the Porsche company as the Type 110, seven different variants of the  were prototyped during 1938 and 1939. Research was done in cooperation with the Agriculture School in Hohenheim, where Porsche conducted many experiments with different engines types and sizes, different gearing and different farm attachments. These Type 110 tractors clearly show the mud lugs on the rear wheels. These devices date all the way back to Ferdinand Porsche’s days at Austro-Daimler when he was unable to arrive at a solution for dealing with traction in mud. Engineer Karl Rabe came up with a simple solution that earned him a short term reward of 500 kronen and long term employment as Chief Engineer at the Professor’s engineering company.

An interesting extension of the Voith fluid coupler was the Porsche-Diesel tractor HydroStop attachment introduced in 1958. It allowed the tractor to be started, steered and stopped with the driver off the tractor and was an accessory available throughout the tractors remaining life.

There were a few other interesting spin-offs of Porsche’s tractor work. Always looking for income, Ferdinand Porsche took on two strange projects for the German Army. One was a Type 293 that was adaptable as a wheeled or track-type tractor. It was a stab at making an inexpensive off-road vehicle that could be used on the Russian front. It was supposed to carry a five-man squad and their equipment as well as pull an artillery piece or trailer. The Type 293 likely never got past the planning stage. Another Schlepper-like tractor project was Type 175, the Ostradschlepper. More a truck than a tractor, it was a high-clearance, steel-wheeled vehicle intended to be used on the Eastern front where the mud would mire the typical German vehicle. At least one prototype was built but series production was never initiated.

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