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Apr 23, 2008
- Actros SLT 4160 8x6/4 heavy-duty transport vehicle for 500-tonne gross combination weight
- Rare Mercedes-Benz heavy tractor unit in operation
- Russian spaceship BURAN fascinates thousands of onlookers
- Kübler heavy-load transport operator: specialised in transport operations
of the highest level of complexity
- It was also an Actros SLT that took the Concorde to the Technik-Museum Sinsheim
In the first days of April, in the port of Rotterdam a crane hoisted the BURAN onto a sixteen-axle low-bed trailer with a Mercedes-Benz Actros SLT 4160 8x6/4 heavy-duty tractor unit, which had previously been placed on a pontoon barge. The first thing onlookers saw when the barge carrying the BURAN came around a bend in the Rhine, was the leaf-green Actros heavy tractor unit of the Kübler haulage company. The Russian space shuttle BURAN (= snowstorm) fascinated spectators all along the Rhine valley, past Cologne, past the famed Loreley rocks and all the way to Speyer, the home of the Technik-Museum.
In the natural harbour at Speyer it was not just the BURAN that riveted the attention of visitors. Numerous heavy transport vehicle fans had also come to see the Actros SLT 4160 8x6/4 and its exotic cargo. Its drive configuration, approved for a maximum gross combination weight of 500 t, makes it a very rare sight indeed in the field of heavy-duty haulage. The Actros SLT 4160 8x6/4 is one of very few four-axle tractor unit with three driven and two steered axles. The all-wheel drive with the three driven axles and differential locks improves traction considerably compared with the 8x4 variant. And that this increased level of traction pays, can easily be seen, whether it is on the muddy ground of the natural harbour at Speyer, or simply on any large building site.
The two steered axles improve the tractor vehicle’s manoeuvrability immensely - and that is what the heavy haulage business is all about, whether it means centimetre-precise manoeuvring when driving off the pontoon barge, or just negotiating a roundabout.
Everything about the drive train of the Actros SLT tractor unit speaks of competence in heavy-duty haulage. The Mercedes-Benz OM 502 LA V8 16-litre turbocharged BlueTec 5 engine with charge-air cooling, delivers 447 kW/ 609 hp and a maximum torque of 2400 Nm at engine speeds between 1080 and 1800 rpm. The Actros SLT is equipped ex works with the largest radiator available. The Actros SLT heavy truck uses a Mercedes-Benz 16-speed G 240 range-change transmission with a WSK 400 torque converter clutch and retarder. The two-gear Mercedes-Benz VG 2400-3W transfer case with reduced-torque off-road ratio makes it possible to avoid gearshifts which entail an interruption of tractive force on slippery ground.
One look at the Actros SLT is enough to feel how it radiates power and self-assurance. Above the sun visor there is a chromed bar upon which four powerful searchlights are mounted, flanked by a compressed-air horn on one side, and a yellow rotating flashing beacon on the other. On the cab rear wall there are three searchlights for working at night. The red-and-white painted bumper and the Titan logo next to the Mercedes-Benz star all add to the powerful impression the Actros SLT makes; and it can afford to look powerful, simply because it is powerful. While the L comfort cab is air sprung, the Actros 4160 SLT 8x6/4 has an additional leaf spring on each of the three axles, giving it a harder suspension than that of the series-production SLT. The cab is tailored to the needs of the heavy-load specialist, because they frequently have to wait out the day at a services area before being allowed back onto the motorway at night under police escort. The cab therefore has ambient lighting, a CD music centre, air conditionning for hot climate zones and additional thermal insulation as well as the Webasto Air Top 2000 hot-air auxiliary heating system for cold climate zones.
Thanks to its strong backbone the Actros 4160 SLT is the ideal tractor vehicle for towing weights of up to 500 tonnes. The dumper truck frame of 9 mmthickness was reinforced; in particular the rear section and the transverse members, in order to mount the trailer hitch for a towing load of up to 500 tonnes. The Rockinger E 56 trailer hitch is attached by means of ten bolts. At the front of the SLT 8x6/4 a heavy-duty coupling is mounted with a maximum shunting capacity of 250 t. The front axle has an axle-load capacity of 9 t. The lifting/ steered stub front axle retrofitted by Titan has an axle load rating of 8 t and is air-sprung. This second front axle enhances the vehicle’s manoeuvrability, in particular when carrying or towing a heavy load. The pneumatic suspension makes variable loading of the axle possible. For this reason, when manoeuvring while carrying a heavy load, the vehicle’s steerability can be increased even more. The leading axle is always mounted 1350 mm in front of the first rear axle. The planetary-gear HD 7 rear axle has a crown wheel diameter of 300 mm, and a load rating of 13 t. The HD 7 axle can thus transfer a very high torque. The small size of the crown wheel of the HD 7 makes a high ground clearance possible. The tyre sizes are: at the front 385/ 65 R 22.5, and at the rear: 315/ 80 R 22.5.
A new feature of this 8x6/4 chassis is its wheelbase of 4200 mm, increased to accommodate the BlueTec 5 system and the radiator adapted to heavy-duty transport operations. Behind the cab, the 900-litre tank, the battery and the compressed-air tank are located. On the right-hand-side of the cab rear wall is the large-capacity oil cooler: the oil from the transmission and the torque converter clutch, subjected to extremely high thermal loads, is cooled by means of this air-oil radiator and a hydraulically-driven fan at the rear. This ensures the best cooling at all times, in spite of the high output demands, the low vehicle speeds and travel over topographically challenging terrain. A hydraulic system for the semi-trailer steering is installed as optional equipment.
This massive concentration of engineering was now waiting to be awakened to life. Before dawn the heavy load transport specialist crews from Kübler, from Scholpp heavy-load crane & transport operator and from the Technik-Museum Speyer, began the preparations for the last phase of the BURAN’s journey, this time overland, to cover the three kilometres separating the Rhine from the Technik-Museum. Unloading the spacecraft in Speyer was impressive: a huge 300-tonne crane hoisted the wings and tail unit of the space shuttle from the barge onto three low-loaders drawn by Actros tractor vehicles in an hour-long high-precision operation. Then at noon the engine of the Mercedes-Benz Actros SLT 8x6/4 was started and the mighty truck, pulling the 16-axle Scheuerle low-loader, dwarfed by the gigantic proportions of the space shuttle, began to inch its way across the specially-built ramp onto firm ground.
Here the driver was able to apply his year-long experience, because, as it was being progressively relieved of the weight of the 195-tonne Actros combination the pontoon began to rise constantly; at the same time, the driver had to negotiate a slight curve in a space of reduced dimensions. This was not as easy as driver Frieder Saam and his Actros 4160 SLT team made it appear to the onlookers. The fuselage of the BURAN with its dead weight of over 70 t, its length of 36 m and its height and width of 9 m, had a very high centre of gravity, meaning an extremely high risk of tipping over in a curve with simultaneous lateral inclination. For this reason the sideways tilt of the low loader was permanently monitored with an electronic level. With the 18 steered axles of the tractor vehicle and its trailer, the driver skilfully manoeuvred the 48-metre-long BURAN transport in an extremely tight space, to place it in the correct starting position for its overland drive.
The convoy, consisting of the Actros SLT 4160 8x6/4 with the fuselage of the BURAN, an Actros SLT 4160 8x4, an Actros 3353 AS with both the shuttle’s wings and a light Actros 2658 LS with the tail, was now ready for the 3-kilometre drive to the Speyer Technik-Museum. These were accompanied by the Scholpp crane trucks and articulated vehicles and the museum workshop vehicles. The convoy was led by police vehicles and motorcycles and enough reporters to make up around fifteen football teams.
The convoy with the BURAN now rolled at walking pace towards Speyer, having to repeatedly open its way through the crowd of around 15,000 onlookers. Punctually, as required by the specially-issued police permit, the BURAN motorcade arrived at the premises of the Speyer Technik Museum. The last official act of the day was the handing over of the shipping documents by Kübler proprietors Hanne and Heinz Rössler to Hermann Layher, head of the Technik-Museum Speyer. They had already worked together transporting the Concorde, and the near future will surely hold further surprises in store for them.