Articulated truck
A truck - officially in Germany articulated vehicle and Switzerland articulated motor vehicle - is a trailer from a tractor (also semitrailer called) and a semi-trailer (including semi-trailers , bridge , trailers or trailer called). Technically, the tractor unit is usually based on a short truck chassis with driver's cab, steering and drive axle (s), engine and gearbox , on the frame of which a fifth wheel coupling (also called fifth wheel plate) is screwed to attach the semi-trailer.
In Germany, the term articulated vehicle for such vehicles is only colloquial, but in Austria it is the legal term for the combination of a tractor unit and a semi-trailer.
history
The development of the semi-trailer is basically a further development of the horse-drawn farm and baggage car, as it has been built in many variants in Europe and North America over many centuries.
The basic principle of this car was mostly a drawbar or a box structure that was firmly connected to the rear axle, placed movably on the front axle and connected with a so-called king pin . Over time, this connection was reinforced by additional supports or slip rings, so that the front axle to the car body became more torsion-resistant. This resulted in the slewing ring or turntable. In English it is also called "Fifth wheel" because of its round shape.
The transfer of this principle to the newly invented motor vehicle must, according to recent research, be attributed to Emil Jagenberg, who is therefore considered to be the inventor of the modern articulated truck with a motorized semi-trailer. Jagenberg needed this special type of motorized truck in order to be able to use it according to the principles of modern logistics on the site of the Jagenberg factory in Düsseldorf, which was being planned and built from 1904 onwards . After longer experiments u. a. With a towing vehicle built by De Dion-Bouton in 1903 , Emil Jagenberg received an imperial patent in 1904, which already contains the design features on which the modern articulated lorry is based to this day. His patent specification no. 168659 of August 21, 1904 bears the pioneering title "Connection of a motor vehicle with a truck supported by a slewing ring".
With the introduction of the Ford Model TT - the truck version of the T-Model - in the USA in 1908 a small, cheaper and quite robust truck became available that could still be used on poor roads and paths. However, it quickly became clear that the payload of 1 short ton (907 kg) was often too heavy for the chassis. Using a trailer increased the transport capacity, but had the disadvantage that if the TT was unloaded, the tractive effort required for the trailer could no longer be brought to the ground.
The first trucks from other manufacturers of this time were also usually based on the chassis of passenger cars and thus had the same problems as the TT. At that time, the vehicle manufacturers had little interest in the development of commercial vehicles and the development of the tractor was not yet ready to provide sufficiently powerful and inexpensive tractors for the road transport of goods.
In the US, the familiar turntable to the fifth wheel was developed ( Fifth wheel coupling ) on and developed this system of interchangeable semi-trailer ( semi-trailer - Semi-trailer). With these, it was now possible to transport two to three times the load and, thanks to the load distribution on the drive and trailer axles, always have sufficient traction to drive the vehicle. The possibility of being able to use a truck (tractor unit) for various transport tasks just by replacing a trailer that can be manufactured cheaply made this system on the American continent the most widespread transport system on the road.
The invention of the fifth wheel is often attributed to US inventor Charles H. Martin and the Martin Rocking Fifth Wheel Co., who invented the device in 1911. The earliest documented patent a fifth wheel is issued in the patent number 2053812 [1], to Charles E. Bradshaw made of corrugated, Virginia, filed March 18, 1936 and granted on September 8, 1936. One third of the patent was Charles Martin, also from Wellville, assigned.
The fifth wheel was further developed over time. While the first couplings still had to be coupled by threading the king pin from above into the fifth wheel plate, today the king pin can slide into the coupling from behind and then locks it automatically.
In Europe, on the other hand, a very dense rail network and various locks and canals for inland navigation were built up until the First World War . Road transport was largely limited to distribution traffic around train stations and ports, which meant that larger trucks were only required later.
In Europe, a network of narrow streets with tight curves and small intersections determined the traffic situation for many years. These were barely passable for the longer articulated lorries, so that here, with the beginning of commercial vehicle construction, the lorry, initially in the form of a tractor and two trailers, and later also the classic truck machine wagon with a load superstructure and trailer.
After the Second World War , large parts of the rail network were destroyed and goods had to be transported by road. The new highways built in the meantime created the necessary infrastructure to make articulated trucks interesting in Europe. The American troops used articulated lorries to supply their units in Europe, and so the articulated lorry began to spread here too.
technology
1. tractor unit
2. semi-trailer
3. Engine compartment
4. Driver's cab or driver's cab
5. Sleeping cabin
6. Roof spoiler
7. Fuel tank
8. Fifth wheel
9. Cargo area
10. Support legs
Tractor unit
The tractor unit is a vehicle derived from a truck that has a fifth wheel instead of a loading area. This fifth wheel consists of a plate with a built-in locking mechanism on which the semi-trailer rests and into which the kingpin of the semi-trailer is coupled. This means that the semi-trailer is movably but securely connected to the tractor unit. A semitrailer tractor usually has a shorter chassis than a comparable truck. Semitrailer tractors have no loading area and are therefore a special type of truck that is considered a tractor according to the road traffic regulations and EU law. All well-known truck manufacturers have tractor units on offer.
A tractor unit and semi-trailer are always required for the purpose of transporting goods. The semitrailer, similar to the trailer , is supplied by the tractor unit with the compressed air required for the braking system and the electrical power for the vehicle lighting , the ABS and other electrical consumers.
To drive with articulated vehicles (solo) is a driver's license of the class B (the tractor vehicle 3.5T GVW), C1 (with a towing vehicle to 7.5 tonnes gross weight) or C (for towing vehicles with more than 7.5 t permissible Total weight) necessary. To drive with a semi-trailer over 750 kg, the towing vehicle also requires the respective trailer driver's license class BE / C1E / CE.
Semi-trailers
The semi-trailer is a kind of long “ trailer ” that has no front axle, but one to four rear axles, as well as additional crank-down supports at the front for hitching and unhitching. The rear axle of the tractor unit virtually replaces the front axle of the semi-trailer. The tractor unit is built very short, so the semi-trailer can be longer.
A special semi-trailer that has to transport a greater weight can also have more axles. In the case of a three-axle semi-trailer, individual axles can be designed as lifting axles that can be raised when driving empty in order to minimize the twisting of the wheels and the wear on the tires ("erasing") when cornering, as well as the rolling resistance and thus fuel consumption (e.g. when driving Empty trips or light loads). Similar to a truck trailer, the compressed air brake lines are connected to the towing vehicle using two hose lines, a third line connects the lighting system of the trailer with the tractor unit. The load of the semi-trailer lies partly on the rear part of the mostly three axles, a considerable part is carried by the tractor unit via the fifth wheel. This has a beneficial effect on the traction of the tractor.
When unsaddling the trailer, it is placed on two seat posts , which are cranked down for this purpose. These supports can be adjusted in height with a crank via a gear unit and a spindle. A power-saving option consists in lowering the tractor-trailer vehicle with an air suspension after cranking down the supports and then driving it away from under the semi-trailer. The design of the bed depends on the intended use, there are countless variations, from the trailer with tipping over curtainsider trailer until the container chassis .
commitment
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Since articulated trucks are not as manoeuvrable as articulated trucks or individual trucks, they are mainly used in long-distance freight transport. They may have a total weight of 40 t; a maximum total weight of 44 t is only permitted in combined transport with ISO containers. In European long -haul transport , two-axle tractors with three-axle trailers (called “Euro” or “standard semitrailer”) are usually used. Articulated vehicles are also widespread as construction site vehicles with tipping bodies.
Special semitrailers are built for large-volume goods transports with a lower payload. These so-called megaliners or jumbo trailers have wheels with a smaller diameter. With a constant overall height, this increases the inner loading height. Alternatively, a second loading level can be drawn in (so-called double decker with 25% more capacity for pallets ). The smaller wheels are, however, a disadvantage in terms of handling and the tires wear off faster. In this case, both the towing vehicle and the semi-trailer have smaller wheels. But there is also an interim solution in which the towing vehicle has normal-sized tires and the trailer has a step in the loading area. Because of its shape, it is colloquially referred to as a gooseneck trailer (gooseneck chassis ). Some trailers also have an integrated tail lift so that the trailer can also be loaded or unloaded in locations without a loading ramp or industrial truck .
Articulated lorries that are designed for the transport of people (for example in local public transport ) are called articulated buses . Furthermore, especially in the USA there is a special caravan construction (a so-called trailer ), which can be placed in the form of a semi-trailer on an adapted pick -up, in which the pick-up acts as a tractor.
Special forms
Germany
In six federal states, so-called EuroCombis (often incorrectly referred to as gigaliners, which is actually the name for a specific vehicle configuration from the Krone vehicle plant ) are currently being used on a trial basis . These are of two different types:
- Type A: a three-axle truck (with a fixed body or swap body) with an attached dolly on which a semi-trailer is guided.
- Type B: a tractor unit with a three-axle semi-trailer and a tandem trailer with a tandem axle.
The other combination types listed under EuroCombi are currently not in use in Germany. These oversized or oversized EuroCombis could only be operated in Germany until the end of 2007 with a special permit. The total length may be a maximum of 25.25 m instead of the usual 16.50 m for a semitrailer or 18.75 m for a truck. The exemption did not extend to the permissible total weight, which remains at 40 t, but may be increased to up to 60 t. An expert opinion from the Federal Highway Research Institute is currently awaited.
Sweden
In Sweden the total weight can be up to 60 t.
United States
In the United States, the Department of Transportation (DOT) has determined the dimensions of semi-trailer trucks to be supported for nationwide traffic on the interstate highway network. 8 feet 6 inches wide (2.59 m), 13 feet 6 inches high (4.12 m), 53 feet trailer length (16.15 m) and a maximum of 80,000 pounds total weight (36.3 t) apply, but no limit the total length of articulated lorries; therefore, long-nosed vehicles with large sleeping cabins continue to dominate the tractor market. These dimensions are being extended by some states, in particular road trains with several trailers are permitted in many places - a "turnpike double" connects two 48-foot trailers (14.6 m) to form a train with a permitted total weight of 147,000 pounds (66, 7 t), the “Rocky Mountain Double” connects a 40-foot trailer (12.2 m) with a 28-foot-6-inch trailer (8.7 m) (the “Pup”) to form a combination up to 129,000 pounds (58.5 t) total weight.
Canada
In Canada the weight limits are higher than in the USA, and the dimensions of long combinations are regulated differently; however, Canada also has regulations regarding the total length of the train and the wheelbase of the tractor. Depending on the configuration, a maximum of 137,500 pounds (62.3 t) gross weight, a maximum of 53 foot trailers (16.2 m) and a total length (of the road train) of up to 75 feet 6 inches (23.0 m) are allowed.
Mexico
In Mexico, some configurations are up to 136,000 pounds (61.7 t) total weight, up to 68.2 feet (20.8 m) total length for single-trailer trucks, and up to 102.7 feet (31.3 m) total length allowed for articulated lorries with two trailers. The high total weights over 60 t have resulted in strict regulations on axle loads, the number and minimum spacing of the axles in order to limit the load on bridges (so-called bridge formula / bridge formulas of the axle configuration).
Advantages and disadvantages of articulated vehicles
advantages
- Flexible exchange of trailers in a company in order to meet travel times
- The semi-trailer can have a very long, continuous loading space that is largely level right up to the bend in the frame and which can be built comparatively inexpensively.
- Unproblematic loading and transport of long goods (such as steel girders )
- It is possible to transport goods that take up relatively little space but are heavy.
- flexible system of many inexpensive semi-trailers with few (expensive) tractor units possible
- Easier (reverse) maneuvering with less complex movement mechanics than with a truck
- lower curb weight compared to road trains with the same permissible total weight
- The tractor unit without a trailer is considered a tractor unit . Tractors are exempt from the Sunday and public holiday driving bans that apply to trucks in some European countries, which enables the driver to remain mobile on Sundays and public holidays and the freight forwarder to plan his vehicle fleet on days when driving is prohibited.
- It is only necessary to touch the ramp for complete loading and unloading (time saving).
- There is no need to frequently disconnect or connect the trailer and towing vehicle, especially when loading and unloading.
- Better driving characteristics because the trailer sways less or hardly at all.
- Lower fuel consumption, as the distance between the tractor and trailer is very small and therefore less turbulence than with a truck. The better driving characteristics also lead to lower consumption, which is 3–5% in total.
disadvantage
- A tractor unit on its own is useless without a semi-trailer, but a truck alone can transport goods without a trailer.
- partly problematic driving behavior of semitrailer tractors when driving without a semitrailer
- Endangered by side winds of empty, large-area semi-trailers
- higher tire wear, especially on semi-trailers without steered axles
- Dangerous winter driving behavior , as in the usual two-axle semitrailer tractor the drive axle of the truck is behind the fifth wheel and the king pin (the traction point of the semitrailer). On slippery and wet roads, the rear axle of the tractor unit therefore tends to break out to the side and want to overtake its own fifth wheel.
- The axle load (especially the drive axle of the tractor) is three tonnes higher on the Euro semitrailer than on the Euro truck, which leads to increased wear and tear on the roads ( ruts ), which is why the utilization of such a vehicle is defined by the EEA member states , nationally specified maximum axle loads is not always possible and can cost up to three tons of payload.
- Problems in switchbacks and narrow driveways
- Swinging out when cornering in the front and rear of the semi-trailer can endanger other road users
- Different tire wear on each axle (only for semi-trailers with more than two axles)
Manufacturer
Manufacturers currently producing for the pan-European market and their brands of large tractor units are:
- DAF , Netherlands
- Mercedes-Benz , Germany
- Iveco , Italy
- MAN , Germany
- Renault , France
- Scania , Sweden
- Volvo , Sweden
Manufacturers of large tractor units currently producing for individual European markets or areas of application are:
- Fuso , Japan
- Hino , Japan
- Isuzu , Japan
- Jelcz , Poland
- KAMAZ , Russia
- MAZ , Belarus
- Otosan , Turkey
- Sisu , Finland
- Titan , Germany
- Urals , Russia
Manufacturers of large tractor units currently producing for the North American market are:
- Freightliner , USA
- Kenworth , USA
- Mack , USA
- Navistar , USA
- Peterbilt , USA
- Volvo, USA
- Western Star , USA
See also list of commercial vehicle manufacturers .
Curiosity
From 1953 to 1970, light railcars built on the basis of semi-trailers for 1000 mm track ran on the Sylt Inselbahn .
Web links
Individual evidence
- ↑ Systematic collection of laws : Art. 11 Para. 2i VTS .
- ↑ PDF of the Austrian Motor Vehicle Act
- ^ Fersen, Olaf von: A century of automotive technology: Commercial vehicles. Düsseldorf: VDI-Verlag 1987, pp. 263, 267.
- ^ Fuhrmeister, Jürgen: Bilker addresses: Himmelgeister Strasse 107. When machines still had speaking names. In: The Bilker observatory. Journal of the Bilker Heimatfreunde, vol. 60, edition 4, July / August 2014.
- ↑ Comprehensive Truck Size and Weight Study: Summary Report. Federal Highway Administration, Research and Innovative Technology Administration (RITA), March 1995, accessed February 19, 2015 .
- ↑ Test DVZ, empirical values forwarding agency
- ↑ See https://www.syltiges.de/modell-sylter-inselbahn-massstab-1-87