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Winter-service exhibition: market launch of the Mercedes-Benz Unimog U 20
- U 20 model is all Unimog
- Designed specifically for small to medium-size local authorities as
well as gardening and landscaping contractors
- Light and manoeuvrable tractor unit offering truck-like comfort
- Demonstration of seven implement combinations for winter and summer work
The seasons have come full circle. After initial demonstrations of the Unimog U 20 with summer-service implements at the Demopark show in Eisenach in June 2007, the latest addition to the Unimog family has now completed its ice and snow test following a tour of German ski resorts. The Unimog U 20 will be widely available, with deliveries set to commence before the end of this quarter. Eight U 20 exhibits, equipped with various implement combinations, showed customers from the municipal and service sectors and journalists just what the compact, manoeuvrable implement carrier is capable of. Jobs dealt with in addition to the principal task of snow clearing included work in green spaces and wooded areas as well as landscape preservation.
What can the U 20 do? Especially when compared with its elder brothers – the U 300, U 400 and U 500 implement carriers – or the Unimog U 3000, U 4000 and U 5000 models designed for extreme off-road conditions? The answer can be summed up in one succinct phrase that requires a little further explanation. The U 20 is all Unimog – in other words the quintessence of the concept, development and testing of the "mini" Unimog first unveiled at the International Commercial Vehicle Show (IAA) in 2006. All-wheel drive, single tyres at the rear as well as at the front, engageable differential locks, portal axles, coil springs, ample power reserves, power take-offs and a powerful hydraulic system, not to mention state-of-the-art truck technology in terms of safety, operation and environmental compatibility, make the U 20 a highly versatile implement carrier fully in keeping with the style of the two larger model series.
The four-cylinder 904 LA engine (110 kW/150 hp), like its counterparts across the entire Mercedes-Benz commercial vehicle range, incorporates highly sophisticated emission-control technology. The Unimog units feature Bluetec technology (nitrogen oxides are eliminated by the addition of urea), comply with the Euro 4 emission standard and also ensure extremely low emissions of particulate matter.
The strong sides of the "mini" Unimog
The U 20 differs from the U 300, U 400 and U 500 professional implement carriers by virtue of its outstanding manoeuvrability (the turning circle of 12.80 metres is on a par with that of a passenger car), reduced weight, lower price and, additionally, its suitability for specific operating conditions. U 20 units are ideal for occasional mowing work in municipalities; however, if such jobs are more of a regular fixture on the work calendar – as at road maintenance depots, for instance – users may miss the power and mowing width of the U 400, not to mention the option of a mowing door offering an excellent view of the mowing areas to the side of the vehicle.
The U 20 is extremely well-suited for snow clearing and gritting in winter; if a grit container holding more than around 2 cubic metres of dry material is required or heavy-duty cutting work needs to be carried out, however, it is usually better to opt for a larger Unimog unit. The U 20 is designed for changing municipal requirements rather than regular jobs that require maximum output and performance. The U 300, U 400 and U 500 implement carriers are far more suitable in the case of the latter.
The U 20 has a permitted gross vehicle weight of between 7.5 and 8.5 tonnes, while the permitted axle load is 4.8 tonnes at the front and rear, meaning that there is plenty of scope for mounting implements. Its high level of manoeuvrability is down to the wheelbase length, which has been shortened by 380 mm to 2700 mm. In contrast to the U 300/U 400/U 500 series, the U 20 features an all-steel cab that is volume-produced at Mercedes-Benz. The spatial concept of the U 20 includes an elegantly adapted stowage box behind the cab. Dual-circuit common hydraulics, power-take-off transmission at the front, power take-off from the transmission and the front mounting plate complete the range of equipment options and allow numerous implements to be used. The engine, transmission, axles and single tyres are all part of the Unimog modular system. The eight-speed transmission allows speeds of between 1.1 and 90 km/h at the rated engine speed. Incidentally, the U 20 is the first Unimog to feature a cab-over-engine design as all other previous Unimog incarnations of this size have been semi-forward-control units or cabs offering an unhindered view.
Local authorities and gardening/landscaping contractors in Germany currently have around 12,000 Unimog vehicles from the 424 and 427 series (U 1200 and U 1400 models) in service, produced in the period between 1982 and 2000. Although they still perform admirably – Unimog vehicles have always been virtually indestructible – many of them are gradually becoming ripe for replacement in order to avoid rising repair costs. Plus they no longer fulfil the latest requirements in terms of ergonomic design, environmental compatibility and ease of operation. This is the segment for which the U 20 has been designed.
In addition to its ability to operate implements, the U 20 has another ace up its sleeve: as a high-horsepower and relatively lightweight tractor vehicle, it can easily achieve a high average speed, even when fully laden with a trailer load of up to 18 tonnes, making it highly suitable for motorway use.
Seven U 20 vehicles with 10 implements in service
Eight Unimog U 20 units, seven of them equipped with various equipment and implement combinations, appeared at the trial driving presentation held at the Schluchsee lake in the Black Forest:
- Winter-service combination featuring CMP3 snowplough and Stratos FST 14 automatic gritter from Schmidt Winterdienst- und Kommunaltechnik GmbH, St. Blasien.
The single-steel-blade snowplough has a clearing width of 2540 mm and is suitable for clearing average to larger quantities of snow. The automatic gritter holds 1.4 cubic metres of salt plus 700 litres of brine.
- Winter-service combination featuring HS5 side-delivery snow blower from Schmidt.
The side-delivery snow blower is ideal for dealing with the snow walls that are formed when snowploughs make several passes through towns or along country roads. This unit can clear large quantities of snow – up to 500 t/h, with a clearing width of 1.8m and height of 1.2m – either loading the snow onto a truck or throwing it up to 35 metres.
- Winter-service combination featuring HES 250 snowplough and STA 1400 TC automatic gritter on a platform made by Gmeiner (Kümmersbrück).
Thanks to its 3 blades in combination with elastomer suspension, the snowplough operates smoothly, which is of particular benefit when working in towns. A clearing width of 2.5 metres is possible in the 30° position.
The abbreviation TC stands for the "Twin Concept" in which two parallel worm conveyors are used to create an extremely flat design. The low design has a low centre of gravity and enables excellent handling and good rear visibility. The automatic gritter can hold 1.4 cubic metres of dry material and, therefore, allows the U 20 unit's payload capabilities to be used to the full when combined with a platform.
- Gmeiner GFS 750 blower-cutter, with elevated side panels at the front (Söder).
With a cutting drum diameter of 750 mm and an operating width of 2.5 m, this heavy-duty implement covers the entire width of the Unimog vehicle. This is why it is also referred to as a "full cutter" in German. Ideal for occasional use in the event of fresh snow drifts or large quantities of fresh snow, it has a throw distance of up to 30 metres. An optional loading chute rotatable through 210° can also be used to take away the snow by truck.
The diagonal elevation of the front platform side panel is a useful aid if bulk materials such as sand, grit or gravel need to be transported on a regular basis. On the one hand the elevated side panel protects the chassis and stowage box during loading by a wheel loader or excavator, on the other hand it prevents the bulk material from "sloshing" or slipping over the side panel when the brakes are applied.
- MFK 400 front boom mower by Mulag (Oppenau) with MK 1100 mower head and torsion frame.
This mower was developed specifically for the Unimog U 20 and municipal mowing work. The front boom mower offers a cross displacement of 1500 mm and is driven by the front PTO shaft. It has a range of 5.1 metres from the vehicle centre, plus it can be used for either left- or right-hand-side operation. The boom can be swivelled diagonally forwards to improve visibility, while a torsion frame that can be locked hydraulically from the driver's area prevents sideways tilt when working with the boom at the side.
- Combination for landscape preservation with HF 200 wood shredder by Dücker (Stadtlohn), low platform (Söder) and ballast weight (Dücker) at the rear.
The shredder, designed for a wood thickness of 200 mm, is driven by the Unimog's front PTO shaft. Three blades shred up to eight cubic metres of wood per hour. The platform supplied by Söder is an all-steel construction and features an extremely low design. If the new, small 315/60 R22.5 tyres are fitted, a loading height of around 1.15 metres can be achieved, which is of particular benefit if the work involves frequent loading by hand/shovel. As an option, Söder also offers high side panels to create a wood chip body. The wood chips produced can then be transported using the same combination.
- Combination featuring F64.1 front cable winch and Palfinger PK 6001 loading crane on Twistlock system by Werner (Trier).
The crane, mounted aft of the cab, rests on a separate frame with special supports and is designed primarily for frequent loading work carried out by local authorities or gardening and landscaping contractors. A patented telescopic system allows the hydraulic supports to disappear completely into the vehicle so they do not protrude at the sides. The maximum capacity is 700 kg with a range of 7.2 metres. The floor control on both sides can be supplemented by an optional radio remote control system. Hose equipment for grabber work is also available.
The entire crane body can be changed quickly as it is connected to the chassis by means of container twist-locks. This means that, for snow-clearing operations, it can be replaced with an automatic gritter from Gmeiner (STA 1500 TCFS), for example, within just a few minutes. In this case, the full payload of the Unimog is then available for grit or salt: 1.5 cubic metres of dry material plus 650 litres of brine.
Most of the U 20 units on display are fitted with the stowage box, available ex factory, which makes it much easier to carry tools, snow chains or protective clothing, for example.
Further vehicles taking part in the exhibition:
- U 290 with winter-service combination from Schmidt (Cirron SL 32, Mitos FST 17 automatic gritter);
- U 300 with SFK 2200 front sweeper from Dücker and Stratos FST 17
gritter by Schmidt;
- U 400 with embankment mower and lopper on DUA 700 boom from Dücker plus branch deflector and glass roof – for protection and optimal visibility when cutting branches and washing tunnels – as well as Hiab 035-2 loading crane;
- U 400 with Schmidt winter-service equipment (KL-V 32 Vario snowplough, Mitos FST 25 automatic gritter);
- U 400 with GVS 250 snowplough and STA 3000 automatic gritter
- U 400 with MFK 500 embankment mower and 2000 clearance cutter from Mulag as well as Mitos FST 30 automatic gritter from Schmidt for working in the interim period, with ISOBUS control system;
- U 500 with GLC 270 snowplough and STA 4400 automatic gritter from Gmeiner;
- U 500 with FS 105 blower-cutter, Stratos Integral S 44 automatic gritter, ISOBUS control terminal; Mercedes-Benz Axor 1833 4x4 (GLS 270 snowplough and STA 6000 automatic gritter from Gmeiner) and Mercedes-Benz Axor 1833 4x4 (MS 34 snowplough and Stratos 50 automatic gritter by Schmidt).
A single control console for multiple implements: ISOBUS for the U 300, U 400 and U 500 series
One notable feature of the U 300, U 400 and U 500 professional implement carriers is the ISOBUS. Following extensive trial runs, this universal implement control system has now entered series production. It allows standardised operation of completely different attachment and mounting implements by means of rotary buttons and pushbuttons. A standardised (ISO) interface is used to transfer the data between the ISOBUS terminal in the cab and the implement controller on the implement. The data are stored and ready to be called up at any time. In this way, various implements can be controlled using one control terminal, without the need for pre-programming and without having to change the software. In spring 2008, this high degree of compatibility will be further enhanced by GPS-supported application data acquisition, as a basis for performance records. Such records are useful for winter-service operations, for example, or for private service providers, who use the data for billing.
A club of specialists
The Unimog comes from a "plant within a plant". The Product Division Special-Purpose Vehicles has its own production line at the Mercedes-Benz plant in Wörth, the site of the Europe's largest truck production facility. Some 750 people work here, building around 2000 Mercedes-Benz Unimog vehicles and 1000 Mercedes-Benz Econic units per year (the latter being truck chassis designed predominantly for waste disposal). A broad selection of specialities is covered as the Mercedes-Benz Unimog is used to meet a wide range of often extreme requirements in a wide range of fields, whether it be the new U 20, the U 300/ U 400/U 500 implement carriers or the U 3000/U 4000/U 5000 off-roaders. As well as performing snow-clearing duties, looking after green spaces and carrying out other forms of gardening and landscaping work, the Unimog units from Wörth also fight forest fires, plant trees, clear ditches, drill holes in the ground, shunt rail vehicles and perform rescue operations on practically impassable terrain. The Universal Motor-Gerät (Universally Applicable Motorised Implement), from which the acronym "Unimog" is derived, has been around for nigh on 60 years, during which time some 325,000 units have been produced.