Mercedes-Benz Unimog. It may have a strange name, but this awesome go-anywhere do-anything workhorse has been getting the job done for upwards of 70 years now. That’s right – the first production Unimog arrived in Germany just after the end of World War II and began life as a humble agricultural vehicle. In the time since, the Unimog has been everything from a military truck to a Dakar support monster, firefighter, and yes, an epic camping vehicle. Did you know it also has a secret life working on the railways of the world? Not in the sense that it performs maintenance to the physical tracks, but rather, it works while riding on the tracks.
Mercedes calls the rail-capable Unimog a road-railer, and the latest model will be on display at the InnoTrans show in Berlin starting today through the end of the week. It carries hydraulically operated train wheels to keep the Unimog on the track, and it rides on special automotive wheels and tyres that can put rubber to the rails for grip and pulling power. And it can definitely pull its own weight, and much more besides. Depending on the configuration, the Unimog can pull 1000 metric tons – or over 2.2 million pounds – worth of train.
And when everything is done, the train wheels come up and the Unimog bounds down the road to the next job, no fuss no muss. No wonder rail companies have used Unimogs as shunters (the rail term for equipment used to move and position rail cars) for years.
For 2018, Mercedes-Benz offers a new drivetrain option on the Unimog road-railer that features a combination of a torque-converter clutch and hydrostatic traction drive. The added capability means the new Unimog can wield various PTO-style attachments in addition to simply pulling massive loads. Some examples on display at InnoTrans include a Unimog set up for clear-cutting rail right-of-way areas, one equipped with an elevated work platform, and even a radio-controlled model outfitted with a crane.
The next time you’re out for a drive and the gates come down at a rail crossing, don’t be surprised if a Unimog ends up crossing your path.
Gallery: Mercedes-Benz Unimog
Mercedes-Benz presents the Unimog at InnoTrans 2018: The Unimog road-railer: Efficient on road and rail
- New for the exhibition: Drivetrain with combination of torque-converter clutch and hydrostatic traction drive now available ex factory
- Show première: Unimog as support vehicle with crewcab for up to seven people
- Unimog with mowing arm meets EN 50128 safety-related-software requirements for EBA (Federal Railway Authority) approval
Stuttgart/Berlin – The latest Unimog road-railers will be on view at the InnoTrans show in Berlin (18 to 21 September), the world's leading international trade fair for the rail sector. The Unimog road-railer is used as a shunting vehicle, for rail and overhead cable maintenance, and for other jobs on and beside the rails. Customers include railway companies, industrial plants with railway sidings, urban transport operators and tram companies as well as providers of railway line construction and track maintenance services.
At this year's InnoTrans show, Mercedes-Benz Special Trucks is presenting a new drivetrain variant featuring a combination of torque-converter clutch and hydrostatic traction drive. This means that a Unimog shunting vehicle is ideally equipped for pulling high loads of up to 1000 t as well as for additional applications, e.g. operating a snow cutter. A host of newly designed system solutions will also be on display. These exhibits demonstrate the wide range of rail applications the Unimog can cover when fitted with implements and bodies from internationally renowned implement manufacturers and bodybuilders.
On display for the first time is a Unimog road-railer with a body for clear cutting work, including an arm that has a digital height limiting function with software certification to EN 50128. This safety feature is a prerequisite for rail approval in the German rail network.
When equipped as a support vehicle, the Unimog road-railer is suitable for urban transport operators and national railways. It allows broken-down trams to be towed away, even on tight bends. This Unimog variant features a crewcab for up to seven people, a box body and hydraulic rerailers
Innotrans 2018 – the railyard and open-air grounds are the attraction
Innotrans is the world's leading international platform and trade fair for the rail sector. 2900 exhibitors from 60 countries will be expecting around 150,000 expert visitors at a site which has been extended and yet is fully booked. Rail vehicles, their technical equipment and interiors, the rail infrastructure sector and all aspects of public rail transport are the major categories. The biggest attraction is always the vehicle exhibition in the railyard and open-air grounds. Here too, the Unimog road-railers are regular visitors. This year the Mercedes-Benz stand is number 0/412 or 0/320 in the open-air area.
Four exhibits (long version)
The Unimog on the rails – behind this lies a meticulously developed operating concept for the Mercedes-Benz implement carrier customised for markets all over the world. At the InnoTrans show in Berlin (from 18 to 21 September 2018), the manufacturer has four exhibits on display to highlight the versatility of the Unimog in this sector, too.
Unimog U 430 with arm for clear cutting work (exhibit)
The Unimog implement carrier with Zagro rail technology and Mulag ME 700 DB rear arm is used by rail infrastructure operators or service providers for clear cutting work along the tracks. One new feature on display at the show is the digital height limiting function with software certification to EN 50128. This safety feature is a prerequisite for rail approval in the German rail network.In addition to this, the implement carrier features standardised mechanical, hydraulic and electrical interfaces for flexible use with different implements and attachments. Depending on the season, infrastructure operators use the Unimog for tasks such as vegetation control or winter maintenance.
Unimog U 423 shunting vehicle with radio remote control and crane (exhibit)
In addition to its ability as a shunting vehicle with a towing capacity of up to 1000 t, the Unimog implement carrier displays its qualities with its wide range of implement and attachment options, too. In addition to being employed as an economical shunting vehicle, it can be used with front attachments such as a snow cutter or with a mounted crane. The U 423 model on display at the show is equipped with rail gear and rail technology from Zwiehoff. This equipment includes radio remote control, a wagon braking system and a pick-up drawbar with damping
In addition to this, a Hiab loading crane with a maximum lifting capacity of 97 kNm and a working reach of 12.4 m is mounted. The Unimog's transmission power take-off drives the crane hydraulics.
The Unimog for shunting is a cost-effective alternative to a shunting locomotive that is advanced in years. Its major advantages include low fuel consumption, environmental compatibility thanks to compliance with the Euro VI emissions standard for commercial vehicles and low running costs – thanks to service and maintenance in the network of Unimog specialist workshops.
Unimog U 423 with elevated work platform (exhibit)
The Unimog U 423 with rail gear and rail technology from French bodybuilder CMAR is customised for the maintenance of overhead lines at urban transport operators. The type 112 TM elevated work platform for two people/320 kg allows a working height of around eleven metres and a side reach of up to 5.8 metres.
This vehicle concept plays to the strengths of the EasyDrive continuously variable hydrostatic traction drive. With remote control of the hydrostatic traction drive, the Unimog can be moved inch-perfectly from the elevated work platform, which is an ideal set-up for performing inspection work on overhead lines. Thanks to its high level of traction, the Unimog is capable of towing a broken-down tram or performing shunting work at the depot.
Unimog U 423 support vehicle with crewcab for urban transport operators (exhibit)
An ideal vehicle for urban transport operators: the Unimog U 423 with Zagro guidance bogie system for very tight bends, a Kronenburg crewcab with space for up to seven people and a Zagro box body for carrying hydraulic rerailers. The Unimog also features a front PTO shaft for operating the hydraulic rerailers and LED floodlights with a separate battery pack. Another advantage of the Unimog: thanks to the installed torque-converter clutch and the resulting increase in starting torque, the Unimog road-railer is capable of towing a rerailed rail vehicle, even on tight bends and on the frequent inclines encountered at urban transport operators. The wheelbase length has been increased due to the space required for the double cab and box body.
On this vehicle, the longest standard wheelbase length of 3900 mm was extended to 4500 mm at Daimler's Customer Tailored Trucks (CTT) plant, which is responsible for customised conversions.
Combination of torque-converter clutch and hydrostatic drive ex factory
The tried-and-tested Unimog road-railer concept includes standard all-wheel drive with inter-axle differential lock and separate differential locks for the front and rear axle, single tyres, and also the torque-converter clutch for towing large loads. The transmission with eight forward and eight reverse gears enables track speeds of up to 50 km/h in both directions. With EasyDrive on board, work speeds are continuously variable between 0.1 and 50 km/h. Furthermore, it is easy to switch between hydrostatic traction drive and manual transmission when on the move.
Innovation prize from 'Privatbahn Magazin'
The Unimog road-railer achieved first place in the Energy & Environment category of the innovation prize after the last Innotrans show. Every two years 'Privatbahn Magazin', a leading business paper in the rail industry, rewards ground-breaking new products and features in the rail sector with a prize for innovation.
The expert jury, comprised of specialists from rail companies, scientist and advisory board members of 'Privatbahn Magazin', were impressed by the Unimog and its environmental compatibility and economy. The focus was on the drive system with the 5.1-litre four-cylinder OM 934 LA Euro VI diesel engine rated at 170 kW (231 hp). This low-maintenance, high-torque Mercedes-Benz engine generation harbours high savings potential when it comes to fuel consumption, especially compared with conventional diesel shunting locomotives. The Unimog also scored points for the fact that its road-railer version is fitted as standard with special tyres and rims for operation on standard gauge and broad gauge (1435–1676 mm). Further advantages of this Unimog variant: fast rerailing and rail/road changeover possible with a hydraulic lifting and pivoting system, speeds on the rails of up to 50 km/h – forwards and backwards - and on the road of up to 90 km/h.
System advantages of the Unimog road-railer at a glance
- Environmental compatibility
The Unimog complies with the stringent Euro VI European emissions standard for commercial vehicles and is therefore an ecofriendly alternative to shunting locomotives and rail vehicles that are advanced in years. The latest Unimog generation features a diesel particulate filter as standard.
The Unimog offers impressive shunting performance thanks to its sophisticated engine technology from large-scale truck production with low fuel consumption. This makes it an economical alternative to shunting locomotives. The Unimog trumps rail-bound vehicles when it comes to service and maintenance costs, too.
- Coordinated system between vehicle and body
Very close cooperation between the leading road-rail manufacturers from the first phase of development right through to marketing. The result is an optimally matched combination of vehicle and body/equipment, including all implements and attachments as well as the necessary rail equipment and approvals.
- Integrated implement drives, and attachment and mounting areas
Mechanical power take-offs such as a front PTO shaft (160 kW), up to four separate hydraulic circuits, electrical interfaces, and four attachment and mounting areas ex factory make the Unimog a professional implement carrier on road and rail, and ensure high flexibility.
- Rapid transfer from rail to road
The Unimog road-railer allows quick and easy rerailing and rail/road changeover at a level area approximately five metres long, for example at level crossings. Thanks to road speeds of up to 89 km/h, the Unimog can move between work sites quickly and also cover road transfers to a filling station or service workshop.
- First-class after-sales service
Unimog service available at more than 650 service centres worldwide. First-class spare parts service using the Mercedes-Benz dealer network.
- Outstanding working and driving comfort
An ergonomically designed workplace, air conditioning, air-sprung seats and excellent visibility to the front and to all the working areas make the Unimog a comfortable and safe workplace. The camera monitor system with up to five separate cameras can be used for rear area monitoring and as a rerailing aid.
- High tractive force thanks to friction between rubber and steel
The high friction value between the rubber tyres and the steel rails ensures excellent traction and enables economical shunting of loads up to 1000 t with a relatively light vehicle weight. The torque-converter clutch available ex factory increases the engine starting torque, thus enabling smooth towing of heavy loads without wear and tear to the clutch.
- Traction on rails provided directly by the Unimog wheels
Using special rims and tyres available ex factory, the Unimog can drive both on standard gauge rails (1435 mm) as well as various international broad gauges with its own wheels. Hydraulically lowerable rail gear ensures reliable guidance on the track. The advantage: no separate rail drive system required.