by Albert Kühnstetter
The jeep in agricultural engineering after World War 2 – developments derived from it.
On D-Day, June 6, 1944, and in the weeks and months that followed, many Jeeps landed on the European continent. The Jeep was the prototype of the off-road vehicle par excellence – a comparatively high speed on the road, four-wheel drive and an off-road capability that was virtually necessary for a military vehicle distinguished it. These characteristics made it an important vehicle in the liberation of Western Europe. And so it soon became a familiar sight in the ruins of post-war Europe.
But what does this little army vehicle have to do with agricultural engineering?
Although the classic Jeep was not a tractor, this vehicle had a considerable influence on the development of four-wheel drive. On the one hand, it made the advantages of four-wheel drive known to a broad group of the population, and on the other hand, it led to the first four-wheel drive boom in tractor construction in the post-war period. The Jeep was serving as the basis, parts supplier and model for many small and makeshift tractors.
But first I would like to take a look at the history of the Jeep
A Short Jeep History
The development of the jeep was initiated on June 27, 1940, with a call for tenders from the U.S. Department of Defense. This invitation to tender was triggered by the high mobility with which the German Army proceeded in its occupation of neighboring countries at the beginning of World War II. The aim of the vehicle was a light-duty, all-terrain vehicle, that could carry a payload of a ¼ ton.
The company Bantam presented a vehicle as early as 1938 that came close to meeting the requirements of this tender. As a result, Bantam was the only supplier able to submit the required documents and prototypes to the Ministry of Defense in time.
Willys-Overland, which also took part in the tender, was unable to complete its prototype in time. The construction from Bantam was awarded the contract. However, the Ministry of Defense did not want to rely on the relatively small Bantam company and – against Bantam’s protests – gave the plans for Bantam’s construction to Willys-Overland and Ford.
All three suppliers were commissioned to rework the design and build 1,500 vehicles. In the end, the Ministry of Defense opted for the Willys-Overland model, which was to go down in military and automotive history as the Jeep. Willys-Overland built 360,000 Jeeps by the end of the war. Ford built another 270,000 Jeeps to order for the U.S. military.
The British Land Rover, which was manufactured on the island from 1948 onwards, followed the same concept as the Jeep. However, it was not designed for the military, but was intended primarily for farmers to carry out light transport work in rough terrain.
Many of the Jeeps stranded in Europe with the invasion, remained on the continent after the war ended and they were released from their military service.
These Jeeps, which remained in Europe, aroused the interest of many technically gifted farmers, craftsmen and engineers interested in the mechanization of agriculture. In the post-war years, this group of people suffered from an acute shortage of raw materials and supplies on the one hand, and were forced by necessity to improvise on the other. These people found the ideal object of activity in the decommissioned Jeeps of the US Army. In the years immediately after World War II, this led to special developments in tractor construction. These were tractors based on the Jeep or for which the Jeep served as a source of inspiration and ideas and also as a parts supplier, such as the Gerwi and Nordtrak Stier, the Pionier or the BTC/BTG tractors.
In addition to these better-known company names, whose tractor development began with the Jeep, there were certainly still many unknown farmers, blacksmiths and mechanics who built a makeshift tractor from a Jeep. This was not limited to the German-speaking countries. In France, too, there were some small companies that used parts or the engine of the Jeep for their tractors. Chosalland or Meublat were mentioned here. As in Europe, there were also entrepreneurs in the USA who built tractors based on the Jeep. One of these was the Empire Tractor, which used the Jeep engine and drivetrain. However, the production period was limited to 1947 and 1948. Little known in Europe, but an important aspect of the Jeep in agricultural engineering were the Jeeps built by Willys-Overland in the post-war period especially for the agricultural sector.
Now to the history of BTC and BTG.
Bayerische Transportfahrzeuge Company GmbH (BTC) and Bayerische Traktoren- und Fahrzeugbau GmbH (BTG)
In some sources, the company name BTC is also written as Bavarian Trucking Company, which would not have been unusual in the early post-war period in the American occupation zone. In any case, BTC used the Jeep as the basis for the tractors the company built until the first half of the 1950s under the name BTC Bavaria.
These designs from Munich were advertised as JEEPDIESEL tractors or BTC JEEP-DIESEL all-purpose tractors. The chassis, axles and drive train of the Jeep were used in these tractors. BTC also took the transmission of the Jeep with 3 forward and one reverse gear. The intermediate gearbox, however, was made smaller with a new pair of wheels. With a top speed of 40 km/h, the Bavaria JEEPDIESEL was a fast tractor by the standards of the time.
The Jeep engine was replaced by the 11 hp single cylinder F1M414 diesel engine from Deutz. The body was removed and the rear bench seat was replaced by a cargo bed. An engine hood was available at an additional cost. The Bavaria tractor was equipped with a PTO. The side mower was available as optional equipment. In addition to the aforementioned Deutz engine, engines from Hatz, MWM or Perkins were also used. The BTC S14 was equipped with either a 14 hp MWM diesel or a 12 hp Hatz engine. In this model, the frame of the Jeep was shortened from 2040 mm wheelbase to 1700 mm in order to achieve better maneuverability. The transmission had 4 forward gears. The S14 was also equipped with a tractorlike engine hood on the Jeep undercarriage. In the first half of the 1950s, there was a gradual shortage of Jeeps released from military service. Thus, the company, renamed Bayerische Transportfahrzeuge Company in 1955 to Bayerische Traktoren- und Fahrzeugbau (BTG), began designing its own tractors during this period.
The D40 model had this engine with just over 2.5 liters of displacement. The D40 had a reversing gearbox with 6 forward and 6 reverse gears, two differential locks and a four-wheel brake. However, the in-house design of the drivetrain proved to be too weak and had to be improved. In addition to Deutz engines, those from Güldner or Perkins were also installed in BTG’s tractors. An example is the BTG imported from Whitlock to Great Britain with a Perkins P4 32 with an output of 32 hp. A cooperation with Deutz was established in1958, in which the BTG designs were sold as Deutz tractors with the Deutz engine hood and Deutz inscription. However, the hoped-for sales success failed to materialize even within the framework of this cooperation. In mid-1960, therefore, there was a restructuring. The company was renamed TATRAC-Traktoren GmbH & Co. KG Munich. However, TATRAC was only responsible for sales. Tractor production was taken over by the construction machinery manufacturer Eisenwerk Gebr. Fischer KG Augsburg in 1961. The Augsburg-based company built the TD60 with the Deutz F4L712 as the power source. This engine produced a good 50 hp and had a displacement of 3.4 liters. The TD60 was equipped with a reverse gearbox with 8 forward and 8 reverse gears. Production ended in the mid-1960s.
Similar to the products of BTC and BTG, Nordtrak was also influenced by the concept of the Jeep.
At the beginning of the history of Nordtrak was George R. Wille, who began using parts of the Jeep to build a tractor in 1947. Among other things, he used the Jeep’s drivetrain with all-wheel drive and 4 equally sized wheels for his tractor called the Stier. The first Stier had a 12 hp engine. It was called Gerwi Stier after the name of the company owner. Wille left the company he had founded as early as 1950.
Franz Westermann joined the company as an investor, and Gerhard Kullik from Deuliewag joined the company on the design side. The company itself had been renamed to Norddeutsche Traktorenfabrik Franz Westermann. In the meantime, the Stier tractors had achieved a certain degree of popularity and demand was increasing. The tractors were now officially called Nordtrak Stier. The company was based in Hamburg. Nothing was changed in the basic concept with permanent all-wheel drive on 4 equally sized wheels. The Stier 30 with 28 hp engine power was introduced in 1951. The largest model was the Stier 480 with a 48 hp 4- cylinder diesel engine. Nordtrak often used engines from MWM.
Due to the complex construction, however, the Stier tractors were comparatively expensive. Secondly, the Stier could only exploit its traction advantage in difficult terrain. Therefore, demand remained low, which ultimately led Nordtrak to bankruptcy in 1956. The parallel to BTC/BTG in the development of the company and its products is obvious.
It is difficult to say to what extent the Jeep also served as a source of ideas for the Unimog. On the one hand, the Jeep was a common sight in Germany in the second half of the 1940s and was probably also familiar to the designers of the Unimog. On the other hand, the designer of the Unimog, Albert Friedrich, had already been working on the concept of a small four-wheel drive transport vehicle for the military during World War II. However, this vehicle was not actually produced. The Unimog ultimately became an independent construction, which was clearly different from the Jeep. The development of the Unimog then took a completely different direction.
The Jeep on the Farms of North America
A chapter largely unknown to us is the Jeep as a farm tractor in North America.
The manufacturer of the Jeep – Willys-Overland was already active as a producer of agricultural machinery after the First World War. With several partners, John N. Willys, the owner of Willys-Overland at the time – bought the Moline Plow Co. which would later be called Minneapolis-Moline. The production program of the Moline Plow Co. included the Universal Tractor. But that is only an aside.
During the Second World War, Willys-Overland produced the Jeep for the US Army. Because of the four-wheel drive and the cross-country mobility, the idea of using the Jeep for farm work was obvious. As early as 1942, the U.S. Department of Agriculture conducted tests with two Jeeps in military version to determine their suitability for farm work. The results were quite promising, but with the clear restriction that the Jeep was not suitable for work in row crops; the track width did not fit the standardized row spacing and the ground clearance was too low for work in taller crops.
In the following years, further tests of the Jeep were carried out to determine its suitability for agricultural work.
Already during the Second World War, Willys-Overland began to think about the business after the war. One of the most important goals was to make the Jeep palatable to American farmers. However, these were not to be decommissioned army Jeeps, as in Europe, but civilian Jeeps that were specially equipped for use in agriculture. The idea was to prevent Jeeps taken out of service by the army from being used on farms, which would have led to a drop in Jeep sales in the post-war period. In 1944, Willys-Overland introduced the CJ-1 model, the first civilian Jeep. It had a larger clutch and a lower transmission ratio.
The new model had a lower gearbox and a lower hitch. This meant that it already had some prerequisites for use in agriculture, e.g. it could be used to pull plows. The CJ-2 was a further development and was then sold as the CJ2A from 1945 onwards. The CJ models were general civilian versions of the Jeep. The agricultural Jeeps were sub-versions of these civilian Jeeps.
The farmers’ acceptance of the Jeep was initially high, but the sales figures fell again in the first half of 1946. Willys-Overland was primarily concerned that inappropriate work and attachment equipment could damage the Jeep’s reputation. Therefore, the company wanted to control sales so that only authorized attachments were used for the Jeep. These implements were also advertised accordingly in the Jeep’s brochures.
In 1949, the next version of the civilian Jeep was introduced. This was the CJ-3A. This model had more space for the driver than its predecessor. Willys-Overland also entered the 1949 Nebraska Tractor Test with the farm version of the CJ-3A. The table at the end of this article shows the comparison of the data of the CJ-3A with tractors of a comparable power category, the Ford 8N and the IH Farmall C. The CJ-3A could keep up quite well with the competitors in this comparison.
With a price of US$ 1,700, the Farm Jeep was more expensive than, for example, a Ford 8N, which was in a comparable performance category and costs US$ 1,500. But in return, the farmer got a tractor with which he could also go shopping or drive to church with his family on Sundays.
Farm Jeep and Jeep Tractor
Willys-Overland reorganized its agricultural engineering activities in 1951. One of the goals, as indicated above, was to ensure that only Willys-Overland approved implements were used for the Jeep and sold through the company’s sales department. This was to safeguard the Jeep’s reputation as a tractor, which had suffered through the use of unsuitable implements.
During this period, two further developments of the CJ-3A were introduced:
• The first was the Farm Jeep, which was equipped with a hydraulic power lift and tractor linkage, as well as reinforced suspension.
• The other was the Jeep Tractor, which was also equipped with a power take-off shaft. On the other hand some equipment needed for road traffic was dropped for the Jeep Tractor, e.g. the spare wheel, the lighting system and the windshield.
The CJ-3B Farm Jeep was the last Jeep designed for farm use, it was sold from 1953. New on the CJ-3B was the engine, the Hurricane engine with 4 cylinders and 2.2 liters of displacement with an output of 72 hp.
The production of special jeeps for the agricultural sector was probably discontinued by Willys-Overland in the second half of the 1950s. In total, about 480,000 units of the 3 civilian model series CJ-2A, CJ-3A and CJ-3B were produced. The number of units of the special Farm Jeeps and Jeep Tractors is unfortunately not known from the sources.
The end of the Jeep in agriculture did not mean the end of this chapter in the history of automobiles. In the meantime, this brand has had a wide variety of owners, but the Jeep as an SUV is still being built today.
My thanks to Hans Ziegler for the opportunity to photograph Jeep and tractors from his collection for this article.
- http://www.cj3a.info/cj3a/farmjeep/ntt.html (Nebraska Test Report)
All photos by the Author.