Das universelle Motor Gerät

A simple idea, a brilliant execution.

Image: mercedes-benz-trucks.com

During the Second World War, Albert Friedrich was head of aero engine design at Daimler-Benz, but also found time to research another project, unbeknown to his bosses.  Friedrich was interested in developing a versatile agricultural vehicle that combined the best features of a tractor and a truck. He described his then nameless concept as an “engine-powered, universally applicable machine for agriculture.” The vehicle would in due course become a valuable tool for many occupations far beyond its originally intended application.

Late 1945 saw Friedrich seeking permission from the occupying US Army to obtain a production licence. This was duly granted, so Friedrich and fellow engineer, Heinrich Rößler, a former colleague at Daimler-Benz, commissioned Eberhard & Söhne in Schwäbisch Gmünd, a city in the eastern part of the German state of Baden-Württemberg, to help them develop and productionise their concept. Eberhard & Söhne was a manufacturer of items in silver and gold, so seemed an unlikely choice for this work, but the project progressed rapidly, thanks to the clarity of the specification.

The vehicle Friedrich and Rößler had designed had switchable rear or four-wheel drive, with differential locks on both axles and equally large tractor-style wheels and tyres all round. A flexible ladder chassis mounted above the axle line and long-travel coil springs gave it exceptional ground clearance and manoeuvrability off-road. Unlike a conventional tractor, it had a forward-mounted cab with a canvas top, behind which was a short integral load deck. There was a built-in tow-hitch at the rear and power take-off points at the front, centre and rear to drive farm machinery. A six-speed gearbox gave it a top speed of 50km/h (31mph), making it more suitable for on-road use than a traditional tractor.

The summer of 1946 saw the first prototypes begin exhaustive trials under the supervision of Christian Dietrich, the engineer appointed to lead the test programme. Dietrich clocked up many miles on public roads and also used a prototype to showcase the vehicle’s abilities to farmers, its initial target market. Another engineer, Hans Zabel, is credited with christening the new vehicle Unimog. This was simply a contraction of Universelle Motor Gerät (Universal Motor Device), which was the name used to label the engineering drawings. In November 1946, Unimog was confirmed as the name the vehicle would carry in production.

Image: Mercedes-Benz AG

Two significant issues now needed to be addressed: sourcing an engine supplier and finding a company to mass-produce the Unimog. Eberhard & Söhne did not have the capacity to undertake series production and built just six pre-production test vehicles, so Goppingen-based machine tool manufacturer, Gebrüder Boehringer, was engaged. The early Unimog vehicles manufactured by Boehringer carried a distinctive painted badge featuring an Ox’s head with U-shaped horns.

Regarding the engine, prototype Unimogs used the Mercedes-Benz M136 petrol engine, but the company’s OM636 diesel unit, at that time under development, would be much more suitable and was used from 1948 onwards in the production vehicles, which carried the model suffix 70200.

As Boehringer was not perceived to be an automobile manufacturer, Friedrich and his team had not only to continue development, but advertise and sell the Unimog themselves. After approximately 600 had been made (150 orders alone arising from the Unimog’s appearance at the 1948 Frankfurt agricultural show), Friedrich realised that demand was such that production needed to be scaled up considerably. Seeking further capital to fund this expansion, Friedrich made contact with his former colleagues at Daimler-Benz, who were very receptive. In early 1951, production of the Unimog was transferred to the Daimler-Benz truck factory at Gaggenau, Baden-Württemberg, where it would remain for the next fifty-one years.

Changes from the Boehringer Unimog were minimal and included a name change to Unimog 2010(1). The Ox head motif remained the sole branding until 1953 when Daimler’s three-pointed star was placed on the grille below it. Three years later, the Ox head badge was deleted. Outputs increased; 1,005 for 1951 rising to 3,799 a year later. In addition to its agricultural target market, the Unimog was increasingly finding public service and military customers.

Image: mecum.com

Under Daimler control, development work hastened changes, which included wider tracks, longer wheelbases, synchromesh transmissions and higher payloads. In 1953 the 2010 was succeeded by the 401 and 402 models. The 401 shared the original’s wheelbase of 1,720mm (67¾”) while the 402 had a 400mm (15¾”) stretch to 2,120mm (83½”). For the first time, an enclosed cab with more rounded bodywork became available. This was outsourced to a company called Westfalia(2) and was nicknamed ‘Froschauge’ (frog eye). A total of 16,250 401/402 models were produced over three years.

1955 saw the launch of what would become a ubiquitous and long-lived version, the 404/404S. This had a more conventional truck profile with a large open or enclosed load bay behind the cab and a carrying capacity of 1.5 tonnes (3,307 lbs). This version found favour with a wide variety of users, including the military, fire service, forestry and utility companies. It would remain in production in a number of different versions for a quarter of a century.

Although never originally intended for military(3) use, the Unimog attracted attention from a number of nations’ armies. The Swiss took over 500, the French took 1,100 while the Bundeswehr took a barely believable 36,638 from a total of 62,242 404/404S versions produced. To improve its on-road performance, the French demanded petrol rather than diesel power and the M180 petrol engine would prove twice as fast as the lethargic diesel. Powered thus and carrying a dozen troops, the Unimog could barrel along at 90km/h on decent surfaces, could pull over four tons of equipment, yet was still able to crawl around on terrain a seasoned fell runner may baulk at. 

Image: bringatrailer.com

Adaptations were mainly performed by the end user to make the Unimog suitable for their specific requirements, from ambulance to agriculture, municipal work to mobile workshop. From 1957, wider cabs were offered. Single cabs were made at Gaggenau while double cabs were contracted out to Wackenhut in Nagold.

Diverse demands and requirements became the norm regarding the Unimog, leading to a veritable labyrinth of three-digit model numbers beginning with a ‘4’. By 1966, 100,000 Unimogs had been produced, that figure having doubled in eleven years. 1968 saw production of the Unimog commence in Gonzalez Catán, Argentina, which continued until 1983.

1974 heralded the arrival of a new design of Heavy (SBU) Unimog models with an entirely new, squarer style.  The existing rounded-cab versions were given the moniker Light (LBU). In 1977, Unimog production passed the 200,000 mark. A period of stability lasted until the mid-1980s when a full series renewal occurred, introducing new Light and Medium series models to the range. These offered more efficient engines and a variety of heavier payloads. 

Image: bringatrailer.com

1992 saw lighter, narrower versions launched with very angular bodywork and an asymmetric bonnet, lower on the driver’s side to enhance visibility. New features included anti-skid electronics, driver operated tyre pressure adjustment and a ‘Servolock’ system for hydraulic attachments front and rear. 

Realising Unimog had become quite the cult vehicle outside its natural environments, Mercedes opted for a little humour, exhibiting the Funmog at the 1994 Off-Road Exhibition in Cologne. Based on a 408 and available in pitch black or metallic red, for your DM150,000, the Funmog came with chrome trim, leather seats and…carpets! Most headed to Japan, where the Funmog was advertised as the perfect vehicle in which to pull up outside your favourite nightclub. 

With ageing equipment and ongoing vehicle development, time was eventually called on the Gaggenau plant in 2002 after the production of over 320,000 Unimogs. A huge send-off party ensued. The excellent Unimog museum remained close by, but production headed to newer and larger facilities at Wörth am Rhein, where figures are now closing in on half a million. 

Image:

One final and unique Unimog advantage has been available for twenty years: Variopilot gives the driver the ability to swap the steering wheel and pedals from left to right at the push of a lever; handy for close-quarters manoeuvring in confined spaces or near cliff-edges, I imagine.  As to the Unimog’s abilities, the Bundeswehr has a saying, “If a Unimog can’t go there, neither can a Panther Tank.”

Over its lifetime, the Unimog has evolved immeasurably but, in terms of its fundamental fitness for purpose, it hasn’t changed at all. You’ll still find it in a field of potatoes, a forest, quarry or mine, equipped as an ambulance or fire truck, or shifting snow and maintaining the verge, and a thousand more roles. Now in its seventy-fifth year of faithful service, it is showing no signs of slowing down. Happy birthday, Unimog!

 

(1) This was, apparently, the serial number carried by the Unimog’s technical drawings.

(2) Westfalia would later achieve fame for its camper van conversions of the VW Type 2 Transporter.

(3) Requesting a production licence for a new German military vehicle in 1945 would probably not have been the brightest idea!

Data sources: aoonauto.com, Daimler archives, Unimog-magazine.de

Author: Andrew Miles

Beyond hope there lie dreams; after those, custard creams?

33 thoughts on “Das universelle Motor Gerät”

  1. The headline should be “Das universelle Motor Gerät” because you would say “das Gerät”.
    In German language abbreviations can become nouns in their own right and so it is with “Unimog”, which to make things more irritating is “der Unimog”.

    1. Aren’t most specific trademarked vehicle names “der”? Der Golf, Der Trabi, Der Dreier…

  2. In 2002 Unimog production very nearly would have come to an end.
    Oft he 6,500 employees in the Gaggenau factory only 700 were making Unimogs and ist enormous number of variants and the high degree of manual work combined with shrinking sales numbers made the Unimog unprofitable. They also found they had lost their customers from the communal/agriculatural sector because Unimogs were getting ever more expensive and were focussed too much on requirements from customers looking for a cross-country vehicle.
    Production was then transferred to Mercedes‘ heavy truck factory in Wörth where all vehicles above 7.5 tons gross weight are made under the provision that the Unimog would become profitable tot he expected level by rationalisation and clearer focussing on its market.
    This led to the split in the product line up between the large, angular military-oriented Unimogs and the smaller, more rounded ones for communal/agricultural customers that can carry equipment from lawnmowers to potato harvesters and from snow plows to corn choppers and are the true universal motor devices of today.
    The communal Unimog also is available as a two-system version with railway wheels with a special transfer box offering gearing of 4 kph maximum speed but a pulling power of more 160 tons making it popular for industrial shunting work

    A fully equipped Unimog has a centre console offering plenty of stuff to play with

    You get up to 32 forward gears and because you have eight gears in a double-H pattern you get lamps indicating the gear you’re in

    When Unimog production was transferred to Wörth Mercedes introduced a scaled-up Unimog called Zetros which is conceptually very similar.

  3. Ah the Unimog. It brings back memories of being a young man.

    In 1977, during my time in the Bundeswehr (german military force), I drove a Unimog (among other things).
    Unfortunately, I can’t say anything about the off-road capabilities.
    I was with a (very) small air force unit. We transported and operated small mobile radar units. On manoeuvres we were placed somewhere in the countryside, near the iron curtain, areas where a dirt road or forest road was the most extreme driving experience. I never experienced the usual army playgrounds.

    What I remember of our army camping trips: the thing was very very narrow inside and very very very noisy.
    The last normal conversation you had with the co-driver was before you put the car in first gear, after which you had to shout at each other.
    But I was young and anything that was uncomfortable and made noise was a hell of a lot of fun.
    In the summer months we sometimes dismantled the tent roof and drove in the convertible, which was not appreciated by our boss, I don’t know why. (For fun I painted our cars with racing stripes and numbers, our boss didn’t like that either, I don’t know why).

    Even though I couldn’t really try it out personally, I’m convinced that where the Unimog can’t go, no other vehicle can go, it will probably be difficult even on foot.

  4. Good afternoon y’all. I love the Unimog and now I feel the portal axle fever is kicking in.

    1. Loving this school day, but who’s going to explain what a portal axle is?

    2. A portal axle has a reduction gear in its hubs so the axle tuve sits higher in relation to the wheel centre for increased ground clearance

    3. The Unimog’s party trick is its incredible axle articulation, made possible by the torque tube axle design and its deliberately wobbly frame.

      Part of this happened by mere incidence because Dutch army insisted that their Unimogs whould have their spare tyre below the load bed instead of between cabin and load bed. As a consequence the frame was modified and its longitudinal beams were no longer going straight below the cabin but became bent inwards, making the frame X shaped instead of a straight H. This further reduced torsional stability and allowed cabin and the rear part of the Unimog to move relative to another by an enormous degree.
      https://www.benzworld.org/attachments/eweb_fwa_uoff_12-jpg.304408/

  5. It’s at times like this I’m actually rather glad I didn’t inherit millions. I have no, repeat no, earthly use for a Unimog, but right now I feel a craving for one…

    1. Imagine dving a large series Unimog in RAL 2011 communal orange with 435-size tyres and not even the most hard-nosed taxi driver would try to push you off the road. That fun alone would be worth driving a Unimog from time to time.

  6. There’s something adorable about a Unimog. It’s difficult to pinpoint but having been subjected to a demonstration at the Gaggenau museum, there’s very little to compare it to anything. Heading vertically up or down, the thing just feels so reassuring, so planted and ultimately capable. And they possess character by the portal axle load

    Here’s a few stationary pictures of them :

    Here’s a Unimog from the Dakar days

    The railway dash

    Answers on a postcard to what this chap is vacuuming

    The Funmog

    Typical conditions to be found at the Hambach mine

    Local tree feller. No dogs were harmed in the taking of this picture but the wood never stood a chance

    1. Hi Andrew. I sorted out the images in your comment above. 🙂

  7. Another brilliant article Andrew. Love Unimogs. They are as iconic as the original Land Rover, but even more versatile. They are fantastic and unique machines. I’ve visited the museum twice now, it’s a must if you are ever visiting that area of Germany.

  8. That picture of the Unimog vacuum truck and W201 caused me actual distress.

    Such honest, functional vehicles. Where did it all go wrong?

  9. If a truck can be cute, then the old Unimog is the cutest. The simple shape and the big tractor wheels are very toy-like.

  10. Very late to the party and playing catch-up, having just spent several days at the Classic Car & Restoration Show at the NEC – you always produce the very best odd-ball articles while I’m elsewhere…. Anyway, thank you Andrew for the Unimog – always on my list of vehicles with which to put the Chelsea tractor brigade in their place. I hadn’t previously noticed that it had Yorkshire wheels – held on not by 4, or 5, but 6 wheel nuts, just like the 1938 Jowett 10hp on which we were working……

    1. Good morning John. How did Andrew, a dyed-in-the-wool Yorkshireman, miss that reference? I’ll be having words…😁

  11. Apologies for the delay in responding to another excellent article Andrew. No excuse apart form grandchildren duties over the weekend!
    They are absolutely superb machines and, having visited the Gaggenau Museum twice, and completed the test circuit, I can confirm their ability to deal with pretty much any gradient and obstacle without any issues.
    Hopefully Andrew can post the images I have sent him as Imgur and I don’t seem compatible sadly.

  12. Having lived at the feet of the Alps for some time Unimogs in winter service were a common sight.
    Either this way

    or with a blower

    Particularly funny when your car was parked where the snow was blown.
    When there was too much snow they blew it on a truck and drove it away

    I remember an opportunity when a Unimog tried to pull a BMW 2002 ouf of a snow covered field (where it had landed thanks to its over enthusiastic driver. The snow was about a metre deep and thankfully did no harm to the BMW or its passengers) and the Unimog got stuck because it was fitted with tyres for universal use. Rescue came in form of another Unimog on tyres with tractor profile which pulled the first Unimog and the BMW out of the snow and onto the road in one go. The biggest problem was to replace the tow rope between ‘Mog #1 and BMW with a rigid tow bar but then the Unimog in front seemed pretty unimpressed by the weight it had to pull.

  13. Thanks for sharing these pictures and experiences, Dave.

    In our part of the world, the council ploughs the snow and salts whatever’s left; even the air (not really) often with trucks that have been temporarily “winterised” into a salt spreader. We have no Unimog’s undertaking such work. In fact apart from the local tree fellers (or is it just the one…?) Unimog’s are in short supply around here. Goodness, I’d leave my role today to drive a modern ‘Mog with this kind of apparatus!

    1. A Unimog with snow chains and a blower is an impressive sight (I always admired the drivers from winter service. Being the first one out on the road driving a Unimog under conditions that force the use of snow chains is pretty scary. They do it for us only to get insulted by idiots who blame them for being too slow or too late).

      The largest blowers are made by a company called Schmidt and can cope with up to two metres of snow in one go with the snow being blown eight or sixteen metres depending on the Unimog driver’s choice.
      What you get is a road looking like this.

      I once followed an intercity coach that wasn’t much taller than the wall of snow on either side of the road that a Unimog we were following had cleared. Every time the coach’s body moved sideways in corners or over bumps it touched the wall of snow on one side (shrieking passengers included) and several bucket loads of snow fell back onto the road or created a cloud of snow in front of our car. You couldn’t see anything laterally because the snow walls were so high but with lights on the snow was reflecting glaringly white and the whole scenery was pretty surreal.

  14. Here’s something interesting for you – there was a very similar machine built in Sydney from 1910 (or so) by Caldwell Vale. It had an 80hp 4-cylinder engine, 4-wheel drive and 4-wheel steer (not sure about brakes!), and was designed to replace bullock teams.

    One of the last things I’ve read about Unimogs in Australia was a few years ago former F1 and touring car racer Larry Perkins developed an overdrive unit for the current generation trucks, with approval by M-B and was having it manufactured by Claas. They’d sold quite a few because it raised the gearing by over 20% and reduced highway cruising fuel consumption at 100km/h by a similar amount.

    1. Looks like an early predecessor of the MB Trac, a specialised farming tractor based on Unimog underpinnings

      The Unimog always used a heavily detuned version of the MB engine. In the state of tune it had in lorries it was able to propel the Unimog up to a bit over 160 kph. One magazine tried it in the Seventies and it was not a recommendable experience. The Unimog’s handling is surely at its limit around the 97 kph top speed because with 435 R 20 all terrain tyres you get the steering precision of a chewing gum.

    2. Ah, takes me back to visiting agricultural shows when I was a lad. And also playing with toy tractors and frontlifts.

      Seeing a Unimog on the M27 fitted up for a tree surgeon yesterday made me wonder how having a chipper fitted to the front can be road legal when there is so much justified attention to making a vehicle deformable and less lethal to other road users.

    3. Are you sure the chipper was for wood and not for cars in front of the Unimog? ‘Mogs have Smarts and Aygos for breakfast…

    4. Haha, I didn’t hang around long enough to find out! My Skoda Superb’s quite substantial, but if a ‘Mog’s hungry enough…

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