A
semi-trailer truck, also known as a
semi,
tractor-trailer, or (in the
United KingdomThe United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
and
IrelandIreland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
)
articulated truckA truck or lorry is a motor vehicle designed to transport cargo. Trucks vary greatly in size, power, and configuration, with the smallest being mechanically similar to an automobile...
or
articulated lorry-Transport:* Lorry or truck, a large motor vehicle* Lorry, or a Mine car in USA: an open gondola with a tipping trough* Lorry , a horse-drawn low-loading trolley-In fiction:...
, is an
articulated vehicleAn articulated vehicle is a vehicle which has a permanent or semi-permanent pivoting joint in its construction, allowing the vehicle to turn more sharply. There are many kinds of articulated vehicles, from heavy equipment to buses, trams and trains...
consisting of a towing engine (
tractor in the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
,
prime mover in
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
or
truck in
IrelandIreland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
, the
United KingdomThe United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
,
CanadaCanada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
and
New ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
), and a
semi-trailerA semi-trailer is a trailer without a front axle. A large proportion of its weight is supported by a road tractor, a detachable front axle assembly known as a dolly, or the tail of another trailer...
(plus possible additional trailers) that carries the freight. A
semi-trailer does not trail
completely behind the towing vehicle, but is attached at a point that is just forward of the rear-most axle of the towing unit, so that some fraction of the weight of the trailer is carried by the prime mover, with most of that at the rear axle (s) of the prime mover, but a small amount at the front axle (s). This arrangement requires both tractor and semi-trailer to be distinct in design from a rigid truck and trailer.
Colloquial terms for semi-trailer truck include
truck and trailer,
transfer truck,
18-wheeler,
semi,
Mack truck (named for a prominent brand),
big rig (US),
transport (Canada),
artic (UK and Ireland),
lorry (UK).
North America
In North America, semi tractors usually have 3
axleAn axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to its surroundings, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle...
s, the front, or "
steerSteering is the term applied to the collection of components, linkages, etc. which will allow a vessel or vehicle to follow the desired course...
", axle having two wheels, and each of the two rear, "drive", axles having a pair of "dualies"
(double wheels) on each side. Thus, the most common configuration of tractor has 10 wheels; however, in some cases dual wheels are replaced by tires known as "super singles" (see below), or wide-base singles, to reduce the weight of the tractor. (The weight reduction is about 180 pounds (81.6 kg) per axle when using super singles). In this case the tractor will only have six wheels. A smaller tractor, having a single drive axle (six wheeler) is often used to pull shorter trailers in tight urban environments, such as downtown areas where a 60 feet (18.3 m) rig would be too difficult to maneuver. Sleeper cabs (trucks with sleeper units) usually don't have single axles, but both day cabs and trucks with sleepers are produced with them.
The
cargo trailerA semi-trailer is a trailer without a front axle. A large proportion of its weight is supported by a road tractor, a detachable front axle assembly known as a dolly, or the tail of another trailer...
usually has two "
tandemTandem is an arrangement where a team of machines, animals or people are lined up one behind another, all facing in the same direction....
" axles at the rear, each of which has dual wheels, or eight wheels on the trailer. Many trailers are equipped with movable tandems and fifth wheels that can be set to adjust the weight on each axle to stay within legal limits.
Although the sum of the weights of the tractor and the trailer (the
gross weight) is normally limited to a certain amount, some roads are marked with a different gross restriction to prevent road damage. Cargoes that exceed allowed weights are usually marked with
overweight loadIn road transport, an oversize load is a load that exceeds the standard or ordinary legal size and/or weight limits for a specified portion of road, highway or other transport infrastructure, such as air freight or water freight. There are also load per axle limits...
and must obtain a permit to use certain roads.
Rules governing the maximum size and weight of vehicles differ from one U.S. state to another. However, since the majority of hauling is done on the interstate system, the vast majority of trucks and trailers made in the U.S. are built to the specifications of the Department of Transportation (DOT), which governs the use of the interstate system. The DOT has established these vehicle limits: 102 inches (2.6 m) wide, 13.5 feet (4.1 m) feet in height, and 80000 pounds (36,287.4 kg) gross weight.
http://ntl.bts.gov/DOCS/cts.html These limits can be exceeded as individual states have the right to issue temporary oversize and/or overweight permits.
Trailer dimensions vary greatly, depending on the amount and type of cargo it was designed to haul. (See types of trailers under Construction, below.)
Although dual wheels are most common, use of two single, wider
tireA tire or tyre is a ring-shaped covering that fits around a wheel rim to protect it and enable better vehicle performance by providing a flexible cushion that absorbs shock while keeping the wheel in close contact with the ground...
s (known as "super singles") on each axle is becoming popular, initially among bulk cargo carriers and other weight-sensitive operators. With a growing desire to reduce greenhouse gas emissions the use of the super single tire is gaining popularity. The three advantages of this configuration are : (1) super singles reduce fuel consumption. Testing on an oval track (Canada 2009) showed 10% fuel savings when using super singles. The savings come from less energy wasted flexing tire side walls. Fewer tire side walls equates to less wasted energy; (2) the lighter tire weight allows a truck to be loaded with more freight; (3) the single wheel covers less of the brake unit, which allows faster cooling and reduces
brake fadeVehicle braking system fade, or brake fade, is the reduction in stopping power that can occur after repeated or sustained application of the brakes, especially in high load or high speed conditions...
.
Perhaps the largest disadvantage is when one tire becomes deflated or destroyed, the remaining tire (in a dual axle configuration) may not prevent the load from causing damage to rim of the deflated tire before the vehicle is stopped. In a dual tire configuration the rim of the deflated tire is prevented from touching the roadway by the fully inflated tire mounted beside it. (Note: it is illegal to drive a commercial vehicle with a deflated or destroyed tire).
Another innovation rapidly growing in popularity is the skirted trailer. The area between the road and the bottom of the trailer frame was previously left open, however the air moving under the trailer is a source of aerodynamic drag. Oval track testing (Canada 2009) proved it is possible to improve fuel economy by 8%, depending on the design and installation configuration of the trailer skirt. The more completely the airflow under the trailer is blocked the better the improvement in fuel economy.
The United States also allows 2-axle tractors to tow two 1-axle 28.5-foot (8.7 m) semi-trailers known officially as
STAA doubles and colloquially as
doubles,
a set, or
a set of joints on all highways that are part of the National Network. The second trailer in a set of doubles uses a
converter gear, also known as a
con-gear or
dolly. This apparatus supports the front half of the second trailer. Individual states may further allow longer vehicles (known as "longer combination vehicles" or
LCVA road train or roadtrain is a trucking concept used in remote areas of Argentina, Australia, Mexico, the United States and Canada to move freight efficiently. The term "road train" is most often used in Australia. In the U.S. and Canada the terms "triples," "turnpike doubles" and "Rocky Mountain...
s), and may allow them to operate on roads other than those part of the National Network.
LCV types include:
- Triples: Three 28.5-foot (8.7 m) trailers; maximum weight up to 129,000 pounds (58.5 t).
- Turnpike Doubles: Two 48-foot (14.6 m) trailers; maximum weight up to 147,000 pounds (66.7 t)
- Rocky Mountain Doubles: One 40 (12.2 m) to 53 (16.2 m) foot trailer (though usually no more than 48 feet) and one 28.5-foot (8.7 m) trailer (known as a "pup"); maximum weight up to 129,000 pounds (58.5 t)
- In Canada, a Turnpike Double is two 53-foot trailers and a Rocky Mountain Double is a 50-foot trailer with 24-foot "pup"
Regulations on LCVs vary widely from state to state. No state allows more than three trailers without a special
permitThe verb license or grant licence means to give permission. The noun license or licence refers to that permission as well as to the document recording that permission.A license may be granted by a party to another party as an element of an agreement...
. Reasons for limiting the legal trailer configurations include both safety concerns and the impracticality of designing and constructing roads that can accommodate the larger
wheelbaseIn both road and rail vehicles, the wheelbase is the distance between the centers of the front and rear wheels.- Road :In automobiles, the wheelbase is the horizontal distance between the center of the front wheel and the center of the rear wheel...
of these vehicles and the larger minimum turning radii associated with them.
Most states restrict operation of larger tandem trailer setups such as triple units, the "Turnpike Double" (twin 48–53 ft units) or the "Rocky Mountain Double." (A full 48–53 ft unit and a shorter 28 ft unit) In general, these types of setups are restricted to tolled turnpikes, such as I-80 through Ohio and Indiana and specific Western states. Tandem setups are not restricted to certain roads any more than a single setup. The exception are the units listed above. They are also not restricted because of weather or "difficulty" of operation.
The long-haul tractors used in interstate travel are often equipped with a "sleeper" behind the driver's
cabThe cab of a truck is an enclosed space in a truck where the driver is seated. The word originated as a short form of cabriolet, not cabin. Some may refer to the tractor unit of a semi-trailer truck as a cab, but this is not the subject of this article...
, which can be anything from a small
bunkBunk may refer to:* bunk , absurd, ridiculous, nonsense, wikt:Bunkum * Bunk , truancy, to "play hookey", to "cut" or "skip" class* Bunk bed, a type of bed in which one bed is stacked over another...
to a rather elaborate miniature
apartmentAn apartment or flat is a self-contained housing unit that occupies only part of a building...
.
Europe
The noticeable difference between
tractor unitA tractor unit, prime mover , road tractor, or traction unit is a heavy-duty commercial vehicle within the large goods vehicle category, usually with a large displacement diesel engine, and several axles. The tractor unit serves as a method of moving trailers...
s in the U.S. and Europe is that almost all European models are "
cabThe cab of a truck is an enclosed space in a truck where the driver is seated. The word originated as a short form of cabriolet, not cabin. Some may refer to the tractor unit of a semi-trailer truck as a cab, but this is not the subject of this article...
over engine" (
COECab-over, also known as COE , cab forward, or forward control, is a body style of truck or van that has a vertical front or "flat face", with the cab of the truck sitting above the front axle...
or
forward control), while the majority of U.S. trucks are
conventional (or
normal control). For repairs, the entire cab hinges forward to allow maintenance access. European trucks, whether small rigid or fully articulated, have a sheer face on the front. This allows for shorter trucks with longer trailers (with larger freight capacity) within the legal maximum total length. Furthermore, it offers greater manoeuvrability and better overview for the driver. In Europe the entire length of the vehicle is measured as total length, while in U.S. the cabin of the truck is normally not part of the measurement.
In Europe usually only the rear tractor axle has twin wheels, while larger size single wheels are used for the cargo trailer. The most common combination used in Europe is a semi tractor with two axles and a cargo trailer with three axles, giving five axles and 12 wheels in total. Lesser used (common in Scandinavia) are tractors with three axles, which feature twin wheels either on one or both rear axles. In addition to the most common three axles variant, cargo trailers with only two or only one axle are in use, again usually with larger single wheels.
United Kingdom
In the
UKThe United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
, to carry the maximum permitted gross weight of 44,000 kg (97,000 lb), both tractor and semi-trailer must have 3 or more axles each. In practice, there is no legal height limit; however, bridges over 16.5 ft (5.03 m) do not have the height marked on them. No heavier vehicles are permitted on the UK road network, except for indivisible loads, which would be classed as abnormal (or oversize); these vehicles are required to display an STGO (Special Types General Order) plate on the front of the prime mover and, under certain circumstances, are required to travel by an authorised route and have an escort.
In the UK, some articulated trucks have 8 tires on 3 axles on the tractor; these are known as 6-wheelers or "6 leggers", with either the centre or rear axle having single wheels which normally steer as well as the front axle and can be raised when not needed (i.e. when unloaded or only a light load is being carried; an arrangement known as a TAG axle). Some trailers have 2 axles which have twin wheels on each axle; other trailers have 3 axles, of which 1 axle can be a TAG axle which has super-single wheels. In the UK, two wheels bolted to the same hub are classed as a single wheel, therefore a standard six-axle articulated truck is considered to have twelve wheels, even though it has twenty tyres. The UK also allows artic truck tractors which have 6 tyres on 2 axles; these are known as 4-wheelers.
Most UK trailers are 45 feet (13.5 metres) long and, dependent on the position of the fifth wheel and
kingpinKingpin may refer to:* Kingpin , the pivot in the steering mechanism* Kingpin , a Swedish metal band from the mid-1980s* Kingpin , a satirical chess magazine...
, a coupled tractor unit and trailer will have a combined length of between 50 and 55 feet (15.25 and 16.75 metres). Although the Construction and Use Regulations allow a maximum rigid length of 60 feet (18.2 metres), this, combined with a shallow kingpin and fifth wheel set close to the rear of the tractor unit, can give an overall length of around 75 feet (22.75 metres), although combinations of this length are usually used only to carry steel or concrete beams. Providing certain requirements are fulfilled, a Special Types General Order (STGO) allows for vehicles of any size or weight to travel on UK roads. However, in practice any such vehicle has to travel by a route authorised by the Department of Transport and move under escort. The escort of abnormal loads in the UK is now predominantly carried out by private companies, but extremely large or heavy loads that require road closures must still be escorted by the police.
As a result of a desk study into
Longer Heavier VehicleLonger Heavier Vehicles , also called super lorries, is a classification of large goods vehicle in the United Kingdom...
s, as of 2009 the consequences of increasing the length of semi-trailers in the UK are being considered, although the study ruled out the adoption of other more wide reaching changes to weight, axle number and length limits, with options up to 11-axle, 34m long, 82 tonne
road trainA road train or roadtrain is a trucking concept used in remote areas of Argentina, Australia, Mexico, the United States and Canada to move freight efficiently. The term "road train" is most often used in Australia. In the U.S. and Canada the terms "triples," "turnpike doubles" and "Rocky Mountain...
s studied.
Continental Europe
The maximum overall length applying in the EU and
EEAEEA or Eea may refer to:* Eea or Electron affinity, the energy required to detach an electron from a singly charged negative ion* River Eea, in Cumbria, England* EEA Helicopter Operations, a Dutch subsidiary of CHC Helicopter...
member states is 18.75 metres with a maximum weight of 40 tonnes, or 44 tonnes if carrying an ISO container. However, rules limiting the semi-trailers to 16.5 metres and 18.75 are met with trucks carrying a standardized 7.82 metre body with one additional 7.82 metre body on tow as a trailer. Since 1996, when Sweden and Finland formally won a final exemption from the
European Economic AreaThe European Economic Area was established on 1 January 1994 following an agreement between the member states of the European Free Trade Association and the European Community, later the European Union . Specifically, it allows Iceland, Liechtenstein and Norway to participate in the EU's Internal...
rules with 60- tonne and 25.25- metre combinations, all other member states gained the ability to adopt the same rules.
Effort to increase the maximum overall length
The 25.25 metres truck combinations were developed under the branding of
EcoCombi which influenced the name of
EuroCombi for an ongoing standardization effort where such truck combinations shall be legal to operate in all jurisdictions of the
European Economic AreaThe European Economic Area was established on 1 January 1994 following an agreement between the member states of the European Free Trade Association and the European Community, later the European Union . Specifically, it allows Iceland, Liechtenstein and Norway to participate in the EU's Internal...
. With the 50% increase in cargo weight, the fuel efficiency increases with an average of 20% with a corresponding relative decrease in carbon emissions and with the added benefit of a third less trucks on the road. The 1996 EU regulation defines a Europe Module System (EMS) as it was implemented in Sweden. The wording of EMS combinations and EuroCombi are now used interchangeably to point to truck combinations as specified in the EU document; however apart from Sweden and Finland the EuroCombi is only allowed to operate on specific tracks in other EU member states.
From 2006, 25.25 m truck trailer combinations are to be allowed on restricted routes within Germany, following a similar (on-going) trial in The Netherlands. Similarly, Denmark have allowed 25.25 metre combinations on select routes. Like in Sweden and Finland, these vehicles in continental Europe will run a 60 ton weight limit. Two types are to be used: 1) a 26 ton truck pulling a dolly and semi-trailer, or 2) an articulated tractor unit pulling a b-double. The UK government has so far decided not to have its own trial of these 60 ton vehicles, but to keep an eye on the other countries' trials.
When using a
dollyA dolly is a small trailer that can be coupled to a truck or trailer so as to support a semi-trailer. The dolly is equipped with a fifth wheel to which the semi-trailer is coupled...
, which generally has to be equipped with lights and a
license plateA vehicle registration plate is a metal or plastic plate attached to a motor vehicle or trailer for official identification purposes. The registration identifier is a numeric or alphanumeric code that uniquely identifies the vehicle within the issuing region's database...
, rigid trucks can be used to pull semitrailers. The dolly is equipped with a
fifth wheelThe fifth wheel coupling provides the link between a semi-trailer and the towing truck, tractor unit, leading trailer or dolly. Some recreational vehicles use a fifth wheel configuration, requiring the coupling to be installed in the bed of a pickup truck as a towing vehicle...
to which the trailer is coupled. Because the dolly attaches to a
pintle hitchA pintle is a pin or bolt, usually inserted into a gudgeon, which is used as part of a pivot or hinge.A pintle/gudgeon set is used in many spheres, for example: in sailing to hold the rudder onto the boat; in transportation a pincer-type device clamps through a lunette ring on the tongue of a...
on the truck, maneuvering a trailer hooked to a dolly is different from maneuvering a fifth wheel trailer. Backing the vehicle requires same technique as backing an ordinary truck/full trailer combination, though the dolly/semi setup is probably longer, thus requiring more space for maneuvering. The tractor-semitrailer configuration is rarely used on timber trucks, since these will use the two big advantages of having the weight of the load on the drive wheels, and the loader crane used to lift the
logTimber may refer to:* Timber, a term common in the United Kingdom and Australia for wood materials * Timber, Oregon, an unincorporated community in the U.S...
s from the ground can be mounted on the rear of the truck behind the load, allowing a short (lightweight) crane to reach both ends of the vehicle without uncoupling. Also construction trucks are more often seen in a rigid + midaxle trailer configuration instead of the tractor + semitrailer setup.
Denmark, the Netherlands, Norway, Sweden and Finland
Denmark, the Netherlands and Norway all allow 25.25 m trucks (the Netherlands from 2000, Denmark from 2008, and Norway from 2008 on selected routes).
In
SwedenSweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
the allowed length is 24 metres (78.7 ft) since 1967. Before that, the maximum length was unlimited - the only limitations were on axle load. What stopped Sweden from adopting the same rules as the rest of Europe, when securing road safety was the national importance of a competitive forestry industry. Finland with the same road safety issues and equally important forestry industry followed suit. The change made trucks able to carry three stacks of
cut-to-lengthCut-to-length logging is a mechanized harvesting system in which trees are delimbed and cut to length directly at the stump. CTL is typically a two-man, two-machine operation with a harvester felling, delimbing, and bucking trees and a forwarder transporting the logs from the felling to a landing...
logs instead of two, as it would be in a short combination. They have one on stack together with a crane on the 6x4 truck, and two additional stacks on a four axle trailer. The allowed gross weight in both countries is up to 60 tonnes (132,277.4 lb) depending on the distance between the first and last axle.
In the negotiations starting in the late 80s preceding the two countries' entries to the
European Economic AreaThe European Economic Area was established on 1 January 1994 following an agreement between the member states of the European Free Trade Association and the European Community, later the European Union . Specifically, it allows Iceland, Liechtenstein and Norway to participate in the EU's Internal...
and later the
European UnionThe European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
, they insisted on exemptions from the EU rules citing environmental concerns and the transportation needs of the logging industry.
In 1995, after Sweden and Finland's entry to the union, the rules changed again, this time to allow trucks carrying a standard
CEN unitA swap body is a standard freight container for road and rail transport.Basic standardization is set with Euronorms EN 283, EN 284 and EN 452 for construction and design, as well as EN 13044 for marking and identification. The panel responsible for developing standards is CEN/TC 119...
of 7.82 metres to draw a 13.6 metres standard semi-trailer on a dolly, a total overall length of 25.25 metres (82.8 ft). Later B-double combinations came into use, often with one 20 ft container on the b-link and a 40 ft container (or two 20 ft containers) on a semi-trailer bed. In allowing the longer truck combinations, what would take two 16.5 metre semi-trailer trucks and one 18.75 metre truck and trailer to haul on the continent now could be handled by just two 25.25 metre trucks - greatly reducing overall costs and emissions.
However, longer and heavier combinations are regularly seen on public roads - special permits are issued for special cargo - not a too uncommon occurrence. Others are: The mining company
Boliden ABNew Boliden is a Swedish mining and smelting company focusing on production of copper, zinc, lead, gold and silver. Following a series of acquisitions during the 1980s and 1990s the company acquired mining and smelting assets of the Finnish mining and smelting company Outokumpu in 2003. Outokumpu...
have a standing special permit for 80 ton combinations on select routes between mines in the inland and the processing plant in
BolidenBoliden is a locality situated in Skellefteå Municipality, Västerbotten County, Sweden with 1,515 inhabitants in 2005. It lies 28,5 kilometers from Skellefteå City....
, taking a load of 50 ton ore. Volvo has a special permit for a 32 metres (105 ft), steering B-trailer-trailer combination carrying two 40 ft containers to and from
Gothenburgs harbourGothenburg is the second-largest city in Sweden and the fifth-largest in the Nordic countries. Situated on the west coast of Sweden, the city proper has a population of 519,399, with 549,839 in the urban area and total of 937,015 inhabitants in the metropolitan area...
and
Volvo TrucksVolvo Trucks is a global truck manufacturer based in Sweden, owned by Volvo Group - AB Volvo it is the world's second largest heavy-duty truck brand....
factory, all on the island of
HisingenHisingen is the fourth-largest island of Sweden , with an area of , and the most populous, forming part of Gothenburg Municipality, Västra Götaland County. It is bordered by the Göta älv in the south and east, the Nordre älv in the north, and the Kattegat in the west...
. Another example is the ongoing project
En Trave Till (lit.
One more pile/stack) started in December 2008. It will allow even longer vehicles to further rationalize the logging transports. As the name of the project points out, it will be able to carry four stacks of timber, instead of the usual three. The test is limited to
NorrbottenNorrbotten is a Swedish province in northernmost Sweden. It borders south to Västerbotten, west to Swedish Lapland, and east to Finland.- Administration :...
county and the
European route E4European route E 4 passes from north to south through Sweden from the border with Finland, total length . The Finnish part lies entirely within Tornio in northern Finland, and is actually only long...
between the timber terminal in
ÖverkalixÖverkalix is a locality and the seat of Överkalix Municipality in Norrbotten County, Sweden with 946 inhabitants in 2005.- Buildings and Structures :* 330 metres tall guyed mast for FM-/TV-broadcasting at 66°18'5" N, 22°51'13" E...
and the sawmill in Munksund (outside
PiteåPiteå is a locality and the seat of Piteå Municipality in Norrbotten County, Sweden. The town has 22,650 inhabitants out of a municipal total of 41,000 in 2008.- Geography :...
). The vehicle is a 30 metre long truck trailer combination with a gross weight exceeding 90 tonnes (198,416 lb). It is estimated that this will give a 20% lower cost and 20-25% CO2 emissions reduction compared to if the timber instead would have been transported with regular 60 ton truck combinations. As the combinations spreads its weight over more axles, braking distance, road wear and traffic safety is believed to be either the same or improved with the 90 ton truck-trailer. In the same program two types of 74 tonnes (163,142.1 lb) combinations will be tested in
DalslandDalsland is a Swedish traditional province, or landskap, situated in Götaland in southern Sweden. Lying to the west of Lake Vänern, it is bordered by Värmland to the north, Västergötland to the southeast, Bohuslän to the west, and Norway to the northwest....
and
Bohuslän' is a Swedish traditional province, or landskap, situated in Götaland on the northernmost part of the country's west coast. It is bordered by Dalsland to the northeast, Västergötland to the southeast, the Skagerrak arm of the North Sea to the west, and the county of Østfold in Norway to the north...
counties in western Sweden. A enhanced truck and trailer combination for use in the forest and a b-double for plain highway transportation to the mill in
SkoghallSkoghall is a locality and the seat of Hammarö Municipality in Värmland County, Sweden with 12,810 inhabitants in 2005. Stora Enso with paper mill and manufacturing being the largest employer. Second largest is Akzo Nobel Base Chemicals AB...
.
Australia
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n road transport has a reputation for using very large trucks and
road trainA road train or roadtrain is a trucking concept used in remote areas of Argentina, Australia, Mexico, the United States and Canada to move freight efficiently. The term "road train" is most often used in Australia. In the U.S. and Canada the terms "triples," "turnpike doubles" and "Rocky Mountain...
s. This is reflected in the most popular configurations of trucks generally having dual drive axles and three axles on the trailers, with 4 tires on each axle. This means that Australian single semi-trailer trucks will usually have 22 wheels which is generally more than their counterparts in other countries. Long haul transport usually operates as B-doubles with two trailers (each with three axles), for a total of nine axles (including steering). In some lighter duty applications only one of the rear axles of the truck is driven, and the trailer may have only two axles.
From July 2007 the Australian Federal and State Governments allowed the introduction of B-triple trucks on a specified network of roads. B-Triples are set up differently to conventional road trains. The front of their first trailer is supported by the
turntableThe fifth wheel coupling provides the link between a semi-trailer and the towing truck, tractor unit, leading trailer or dolly. Some recreational vehicles use a fifth wheel configuration, requiring the coupling to be installed in the bed of a pickup truck as a towing vehicle...
on the prime mover. The second and third trailers are supported by turntables on the trailers in front of them. As a result, B-Triples are much more stable than road trains and handle exceptionally well.
True road trains only operate in remote areas, regulated by each state or territory government.
In total, the maximum length that any articulated vehicle may be (without a special permit and escort) is 53.5 metres (175.5 ft), its maximum load may be up to 164 tons (361,558 lb) gross and may have up to 4 trailers. However, heavy restrictions apply to the areas where such a vehicle may travel in most states. In remote areas such as the
Northern TerritoryThe Northern Territory is a federal territory of Australia, occupying much of the centre of the mainland continent, as well as the central northern regions...
great care must be taken when sharing the road with longer articulated vehicles that often travel during the day time, especially 4 trailer road trains.
In most areas a truck is generally limited to two trailers and a total length of 26 metres (85 ft) and in urban areas this length limit is further reduced to 19 metres (62 ft). 25 or 26 metre - with permits from state authorities - (82 ft to 85 ft), 62.5 ton (137,788 lb) B-doubles are very common in all parts of Australia including state capitals and on major routes may outnumber single trailer configurations.
In Australia, both conventional tractor units and cabovers are common, however cabovers are most often seen on B-Doubles on the eastern seaboard where the reduction in total length allows the vehicle to pull longer trailers and thus more cargo than it would otherwise.
Super single tires are sometimes used on tri-axle trailers. The suspension is designed with travel limiting, which will hold the rim off the road for one blown or deflated tire for each side of the trailer, so a trailer can be driven at reduced speed to a safe place for repair. Super singles are also often used on the steer axle in Australia to allow greater loading over the steer axle. The increase in loading of steer tires requires a permit.
Semi-truck manufacturers
These are for tractor unitA tractor unit, prime mover , road tractor, or traction unit is a heavy-duty commercial vehicle within the large goods vehicle category, usually with a large displacement diesel engine, and several axles. The tractor unit serves as a method of moving trailers...
s, not straight, rigid, box or other heavy vehicles.
In the United States:
- American Coleman
The American Coleman was line of semi trucks built from the 1950s into the 1970s. This truck in airfield operations, military applications, and for the Coleman Company to deliver their products to distributors. The cab-over design had no fifth wheel, instead the trucks frame locked into position by...
- Ford (sold to DaimlerChrysler in 1998 and renamed Sterling)
- Freightliner
- Kenworth
Kenworth is an American manufacturer of medium and heavy-duty Class 8 trucks based in Kirkland, Washington, United States, a suburb of Seattle. It is a subsidiary of PACCAR, and is also a former manufacturer of transit buses and school buses.-History:...
- Navistar International
Navistar International Corporation is a United States-based holding company that owns the manufacturer of International brand commercial trucks, MaxxForce brand diesel engines, IC Bus school and commercial buses, Workhorse brand chassis for motor homes and step vans, and is a private label...
- Mack
- Peterbilt
Peterbilt Motors Company is an American manufacturer of medium- and heavy-duty Class 5 through Class 8 trucks headquartered in Denton, Texas. Founded in 1939 Peterbilt operates manufacturing facilities in Denton, Texas , and Sainte-Thérèse, Quebec...
- Pro star International
- Sterling Trucks
Sterling Trucks, a manufacturer of heavy duty trucks, was a subsidiary of Daimler Trucks North America, based in Portland, Oregon, United States, a member of the Daimler AG Truck Group. It was originally the heavy truck division of Ford Motor Company, but was purchased and rebranded in 1997....
- Volvo Trucks
Volvo Trucks is a global truck manufacturer based in Sweden, owned by Volvo Group - AB Volvo it is the world's second largest heavy-duty truck brand....
- Western Star
Western Star may refer to:* Western Star Trucks* Western Star * Western Star ButterNewspapers* The Western Star * The Western Star * The Western Star...
- Hino
-External links:Global* * * Overseas offices****.*.***.*.* - Philippines**...
In Europe:
- ADR Grup Trailer
- DAF Trucks
DAF Trucks NV is a Dutch truck manufacturing company and a division of PACCAR. Its headquarters and main plant are in Eindhoven. Cabs and axle assemblies are produced at its Westerlo plant in Belgium...
- Mercedes-Benz
Mercedes-Benz is a German manufacturer of automobiles, buses, coaches, and trucks. Mercedes-Benz is a division of its parent company, Daimler AG...
- Iveco
Iveco, an acronym for Industrial Vehicle Corporation, originally an alliance of European commercial vehicle manufacturers such as Fiat , Unic and Magirus. Iveco is now an Italian truck, bus, and diesel engine manufacturer, based in Turin...
- MAN
- Renault Trucks
Renault Trucks is a French truck manufacturer with its corporate headquarters at Saint-Priest near Lyon. Originally part of Renault, it has been owned by Volvo Group since 2001....
- Scania
- Volvo Trucks
Volvo Trucks is a global truck manufacturer based in Sweden, owned by Volvo Group - AB Volvo it is the world's second largest heavy-duty truck brand....
- MAZ
- Kamaz
KAMAZ is a Russian truck manufacturer located in Naberezhnye Chelny, Tatarstan, Russian Federation. KAMAZ opened their doors in 1976...
- Tatra
- Sisu
Sisu Auto is a Finnish truck company. Its name comes from the Finnish word sisu meaning guts, grit and determination.Sisu Auto subsidiary company SISU Defence produces high mobility tactical vehicles for military use.-History:*Sisu established in 1931...
- ZiL
ZIL and similar may refer to:*Zil, a village in the Tabasaran rayon of Dagestan, Russia*Zil stands for Zulfikar Industries Pvt. Ltd. Pakistan, a Chemical factory in Pakistan producting soaps and related chemical products since 1976...
(needs verification)
In Japan and some other Asia Pacific regions:
- Hino
Hino can mean:A Place:*Hino, Shiga*Hino, Tokyo*Hino, Tottori*Hino District, Tottori*Lake Hino in EstoniaA Company:*Hino Motors, Ltd.A Person*Rei Hino, a character on Sailor Moon*Hikari Hino, a Japanese porn star...
- Nissan Diesel
- Mitsubishi Fuso
- Isuzu
, is a Japanese car, commercial vehicle and heavy truck manufacturing company, headquartered in Tokyo. In 2005, Isuzu became the world's largest manufacturer of medium to heavy duty trucks. It has assembly and manufacturing plants in the Japanese city of Fujisawa, as well as in the prefectures...
- Tata Motors
Tata Motors Limited is an Indian multinational automotive corporation headquartered in Mumbai, India. Part of the Tata Group, it was formerly known as TELCO...
Other countries:
- Ashok Leyland
Ashok Leyland is a commercial vehicle manufacturing company based in Chennai, India. Founded in 1948, the company is one of India's leading manufacturers of commercial vehicles, such as trucks and buses, as well as emergency and military vehicles. Operating six plants, Ashok Leyland also makes...
(India)
- FAW
FAW Group Corporation is a state-owned enterprise with publicly traded subsidiaries: FAW Car Company , Tianjin FAW Xiali Automobile Co Ltd , Changchun FAWAY Automobile Components Co Ltd ....
(China)
- Foton
Beiqi Foton Motor Co., Ltd. , , often shortened to Foton or BFC, is a Chinese company making trucks and agricultural machinery.This BAIC subsidiary makes commercial trucks in a joint venture with Daimler AG, called Beijing Foton Daimler Automobile Co., Ltd...
(China)
- Volkswagen Trucks and Buses
Volkswagen Trucks and Buses , , is a Brazilian manufacturer of commercial vehicles. It manufactures heavy trucks and buses under the Volkswagen Commercial Vehicles marque....
(Latin America, South Africa)
- Volvo Trucks
Volvo Trucks is a global truck manufacturer based in Sweden, owned by Volvo Group - AB Volvo it is the world's second largest heavy-duty truck brand....
Construction
Types of trailers
There are many types of semi-trailers in use, designed to haul a wide range of products. See
semi-trailerA semi-trailer is a trailer without a front axle. A large proportion of its weight is supported by a road tractor, a detachable front axle assembly known as a dolly, or the tail of another trailer...
for more detail.
- Box truck
A box truck, also known as a cube truck, cube van, bob truck, box van, or straight truck, is a truck with a cuboid-shaped cargo area.-Road vehicles:...
- Bus
A trailer bus or articulated trailer bus is a bus formed out of a bus bodied semi-trailer pulled by a conventional tractor unit in the same way as a conventional articulated semi-trailer truck....
- Refrigerator truck
A refrigerator truck is a van or truck designed to carry perishable freight at specific temperatures. Like refrigerator cars, refrigerated trucks differ from simple insulated and ventilated vans , neither of which are fitted with cooling apparatus...
, (aka. ReeferA refrigerated container or reefer is an intermodal container used in intermodal freight transport that is refrigerated for the transportation of temperature sensitive cargo....
)
- Tanker
A tank truck or road tanker is a motor vehicle designed to carry liquefied loads, dry bulk cargo or gases on roads. The largest such vehicles are similar to railroad tank cars which are also designed to carry liquefied loads...
- Dry Bulk
- Flatbed truck
A flatbed truck is a type of truck which can be either articulated or rigid. As the name suggests, it has an entirely flat, level 'bed' body with no sides or roof...
- Lowboy
A lowboy or dolly in Australia is a semi-trailer with two drops in deck height: one right after the gooseneck and one right before the wheels. This allows the deck to be extremely low compared with other trailers...
- Car
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
hauler
Coupling and uncoupling
The cargo trailer is, by means of a
king pin, hooked to a horseshoe-shaped quick-release coupling device called a
fifth wheelThe fifth wheel coupling provides the link between a semi-trailer and the towing truck, tractor unit, leading trailer or dolly. Some recreational vehicles use a fifth wheel configuration, requiring the coupling to be installed in the bed of a pickup truck as a towing vehicle...
or a turntable hitch at the rear of the
towing engineA tractor unit, prime mover , road tractor, or traction unit is a heavy-duty commercial vehicle within the large goods vehicle category, usually with a large displacement diesel engine, and several axles. The tractor unit serves as a method of moving trailers...
that allows easy hook up and release. The truck trailer cannot move by itself because it only has wheels at the rear end, hence the name
semi-trailer: it requires a forward
axleAn axle is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to its surroundings, with the wheels rotating around the axle. In the former case, bearings or bushings are provided at the mounting points where the axle...
, provided by the towing engine, to carry half the load weight. The vehicle has a tendency to fold at the pivot point between the semi and the trailer when braking hard at high speeds. Such a truck accident is called a 'trailer swing', although it is commonly described as a 'jackknife'. 'Jackknifing' is a condition where the tractive unit swings round against the trailer: not vice-versa. See:
jackknifingJackknifing means the folding of an articulated vehicle such that it resembles the acute angle of a folding pocket knife. If a vehicle towing a trailer skids, the trailer can push it from behind until it spins round and faces backwards. This may be caused by equipment failure, improper braking, or...
.
Braking
Semi trucks use air pressure, rather than
hydraulicHydraulics is a topic in applied science and engineering dealing with the mechanical properties of liquids. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the engineering uses of fluid properties. In fluid power, hydraulics is used for the generation, control,...
fluid, to actuate the
brakeA brake is a mechanical device which inhibits motion. Its opposite component is a clutch. The rest of this article is dedicated to various types of vehicular brakes....
s mainly due to the much larger braking forces required. This also allows for ease of coupling and uncoupling of trailers from the tractor unit, as well as reducing the potential for problems common to hydraulic systems, such as leakage or brake failure caused when overheated brake fluid vaporizes in the hydraulic lines. The most common failure is "brake fade," usually caused when the drums or discs and the linings of the brakes overheat from excessive use.
The parking brake of the tractor unit and the emergency brakes of the trailer are spring brakes that require air pressure in order to be released. They are applied when air pressure is released from the system, and disengaged when air pressure is supplied. This is an emergency feature which ensures that if air pressure to either unit is lost, the trailer will stop to a grinding halt instead of not stopping and becoming uncontrollable.
The trailer controls are coupled to the tractor through two "glad-hand" connectors, which provide air pressure, and an electrical cable, which provides power to the lights and any specialized features of the trailer.
"Glad-hand" connectors (also known as "palm couplings,") are air hose connectors, each of which has a flat engaging face and retaining tabs. The faces are placed together, and the units are rotated so that the tabs engage each other to hold the connectors together. This arrangement provides a secure connection, but allows the couplers to break away without damaging the equipment if they are pulled, as may happen when the tractor and trailer are separated without first uncoupling the air lines. These connectors are similar in design to the ones used for a similar purpose between railroad cars.
Two air lines control the trailer unit. An emergency or main air supply line pressurizes the trailer's air tank and disengages the emergency brake, and a second service line controls the brake application.
In the UK male/female quick release connectors "red line" or emergency, have a female on the truck and male on the trailer and a "yellow line" or service has a male on the truck and female on the trailer. This avoids coupling errors (causing no brakes) plus the connections will not come apart if pulled by accident. The three electrical lines will fit one way round a primary black a secondary green and an ABS lead, all of these lines are collectively known as "suzies" or "suzie coils".
Another braking feature of semi-trucks is the
engine brakingEngine braking is where the retarding forces within an engine are used to slow a vehicle down, as opposed to using an external braking mechanism, for example friction brakes or magnetic brakes....
, which could be either compression brake (usually shortened to "
Jake brakeA compression release engine brake, frequently called a Jake brake or Jacobs brake, is an engine braking mechanism installed on some diesel engines...
") or
exhaust brakeAn exhaust brake is a means of slowing a diesel engine by closing off the exhaust path from the engine, causing the exhaust gases to be compressed in the exhaust manifold, and in the cylinder. Since the exhaust is being compressed, and there is no fuel being applied, the engine works backwards,...
or combination of both. The use of compression brake alone however produces a loud and distinctive noise, and owing to noise pollution, some local municipalities have prohibited or restricted the use of engine brake systems inside their jurisdictions, particularly in residential areas. The advantage to using this instead of conventional brakes is that a truck can travel down a long grade without overheating its wheel brakes. Some vehicles can also be equipped with hydraulic or electric
retardersA retarder is a device used to augment or replace some of the functions of primary friction-based braking systems, usually on heavy vehicles....
which have an advantage of near silent operation.
Transmission
Because of the wide variety of loads the "semi" may carry, they usually have a
manual transmissionA manual transmission, also known as a manual gearbox or standard transmission is a type of transmission used in motor vehicle applications...
to allow the driver to have as much control as possible. However, all truck manufacturers now offer
semi-automatic transmissionA semi-automatic transmission is an automobile transmission that does not change gears automatically, but rather facilitates manual gear changes by dispensing with the need to press...
s (manual gearboxes with automated gear change), as well as automatic transmissions.
"Semi" truck
transmissionsA machine consists of a power source and a power transmission system, which provides controlled application of the power. Merriam-Webster defines transmission as: an assembly of parts including the speed-changing gears and the propeller shaft by which the power is transmitted from an engine to a...
can have as few as 9 forward speeds or as many as 18 forward speeds (plus 2 reverse speeds). A large number of transmission ratios means the driver can operate the engine more efficiently. Modern on-highway diesel engines are designed to provide maximum torque in a narrow RPM range (usually 1200-1500 RPM); having more gear ratios means the driver can hold the engine in its optimum range regardless of road speed (drive axle ratio is also a critical factor).
A ten speed manual transmission, for example is controlled via a six-slot H-box pattern, similar to that in five-speed cars — five forward and one reverse gear. Gears six to ten (and high speed reverse) are accessed by a Lo/High range splitter; gears 1-5 are Lo range; gears 6-10 are High range using the same shift pattern. A Super-10 transmission, by contrast, has no range splitter; it uses alternating "stick and button" shifting (stick shifts 1-3-5-7-9, button shifts 2-4-6-8-10). 13,15 and 18 speed transmission have the same basic shift pattern, but include a splitter button to access to additional ratios found in each range.
Another difference between semi-trucks and cars is the way the clutch is set up. On an
automobileAn automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
, the clutch pedal is depressed full stroke to the floor for every gear shift to ensure the gearbox is disengaged from the engine. On a semi-truck with
constant mesh transmissionA non-synchronous transmission is a form of transmission based on gears that do not use synchronizing mechanisms. They are found primarily in various types of agricultural, and commercial vehicles...
(non synchronized), such as by the
EatonEaton Corporation is a global diversified power management company with 2010 sales of $13.7 billion. The company is a leading provider of electrical components and systems for power quality, distribution and control; hydraulics components, systems and services for industrial and mobile equipment;...
Roadranger series, not only is
double clutchA double clutch is a driving procedure primarily used for vehicles with an unsynchronized manual transmission...
ing required, but a clutch brake is required as well. The clutch brake stops the rotation of the gears, and allows the truck to be put into gear without grinding when stationary. The clutch is pressed to the floor only to allow smooth engagement of low gears when starting from a full stop; when moving, the clutch pedal is pressed only far enough to break torque for gear changes.
Lights
An electrical connection is made between the tractor and the trailer through a cable often referred to as a "pigtail." This cable is a bundle of wires in a single casing. Each wire controls one of the electrical circuits on the trailer, such as running lights, brake lights, turn signals, etc. A standard cable would break when the rig went around corners so it is coiled and retains these coils when not under tension. It is these coils that cause the cable to look like a pigtail.
In most countries a trailer or semi-trailer must have minimum
- 2 rear lights (red)
- 2 stop lights (red)
- 2 turning lights; one for right and one for left, flashing (amber; red optional in North America)
- 2 marking lights behind if wider than certain specifications (red; plus a group of 3 red lights in the middle in North America)
- 2 marking lights front if wider than the truck or wider than certain specifications (white; amber in North America)
Underride guard
This is an assembly hanging down from the bottom of the rear of the trailer. It is intended to provide some protection for cars which start to run into the rear of the trailer. This came into use in the aftermath of the accident that killed
Jayne MansfieldJayne Mansfield was an American actress working both in Hollywood and on the Broadway theatre...
on June 29, 1967; the car she was in hit the rear of a tractor-trailer. The bottom of the rear of the trailer is near head level for an adult in a car, and without the underride guard, the only protection for such an adult's head
in such an accident would be the car's windshield.
Driver's license
A special
driver's licenseA driver's license/licence , or driving licence is an official document which states that a person may operate a motorized vehicle, such as a motorcycle, car, truck or a bus, on a public roadway. Most U.S...
is required to operate various commercial vehicles.
Canada
Regulations vary by province. A license to operate a vehicle with air brakes is required (i.e., normally a Class I, II, or III commercial license with an "A" or "S" endorsement in provinces other than Ontario). In
OntarioOntario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....
, a "Z" endorsement is required to drive any vehicle using air brakes; in provinces other than Ontario, the "A" endorsement is for air brake operation only, and an "S" endorsement is for both operation and adjustment of air brakes. Anyone holding a valid Ontario driver's license (i.e., excluding a motorcycle license) with a "Z" endorsement can legally drive any air-brake-equipped truck-trailer combination with a registered- or actual-gross-vehicle-weight (i.e., including towing- and towed-vehicle) up to 11 metric tonnes, that includes one trailer weighing no more than 4.6 tonnes if the license falls under the following three classes: Class E (school bus—maximum 24-passenger capacity or ambulance), F (regular bus—maximum 24-passenger capacity or ambulance) or G (car, van, or small-truck). A Class B (any school bus), C (any urban-transit-vehicle or highway-coach), or D (heavy trucks other than tractor-trailers) license enables its holder to drive any truck-trailer combination with a registered- or actual-gross-vehicle-weight (i.e., including towing- and towed-vehicle) greater than 11 tonnes, that includes one trailer weighing no more than 4.6 tonnes. Anyone holding an Ontario Class A license (or its equivalent) can drive any truck-trailer combination with a registered- or actual-gross-vehicle-weight (i.e., including towing- and towed-vehicles) greater than 11 tonnes, that includes one or more trailers weighing more than 4.6 metric tonnes.
United States
Drivers of semi-trailer trucks generally require a Class A
commercial driver's licenseA Commercial Driver's License is a driver's license required in the United States to operate any type of vehicle which has a gross vehicle weight rating of 26,001 lb or more for commercial use, or transports quantities of hazardous materials that require warning placards under Department of...
to operate any combination vehicles with a Gross Vehicle Weight Rating (or GVWR) in excess of 26000 pounds (11.8 t). Some states (such as
North DakotaNorth Dakota is a state located in the Midwestern region of the United States of America, along the Canadian border. The state is bordered by Canada to the north, Minnesota to the east, South Dakota to the south and Montana to the west. North Dakota is the 19th-largest state by area in the U.S....
) provide exemptions for farmers, allowing non-commercial license holders to operate semis within a certain range of their farm within the state. Also a person under the age of 21 cannot operate a commercial vehicle outside the state where the commercial license was issued. A person must be at least 18 in order to be issued a commercial license.
In addition,
Endorsements are necessary for certain cargo and vehicle arrangements and types;
- H - Hazardous Materials (HazMat or HM) - necessary if materials require HM placards.
- N - Tankers - the driver is acquainted with the unique handling characteristics of liquids tankers.
- X - Signifies Hazardous Materials and Tanker endorsements, combined.
- T - Doubles & Triples - the licensee may pull more than one trailer.
- P - Buses - Any Vehicle designed to transport 16 or more passengers (including the driver).
- S - School Buses - Any school bus designed to transport 11 or more passengers (including the driver).
- W - Tow Truck
Taiwan
The Road Traffic Security Rules (zh:道路交通安全規則) require a combination vehicle driver license to drive a combination vehicle . These rules define a combination vehicle as a motor vehicle towing a heavy trailer, i.e., a trailer with a gross weight of more than 750 kilograms (1,653 lb).
Europe
A category CE driving license is required to drive an articulated lorry.
Australia
Truck drivers in Australia require an endorsed license. These endorsements are gained through training and experience. The minimum age to hold an endorsed licence is 18 years, and/or must have held open (full) driver's licence for minimum 12 months.
The following are the heavy vehicle license classes in Australia:
- LR- A Light Rigid 'Class LR' covers a rigid vehicle with a GVM of more than 4.5 tons but not more than 8 tons. Any towed trailer must not weigh more than 9 tons GVM. Also includes vehicles with a GVM up to 8 tons which carry more than 12 adult including the driver and vehicles in class 'C'.
- MR- A Medium Rigid 'Class MR' covers a rigid vehicle with 2 axles and a GVM of more than 8 tons. Any towed trailer must not weigh more than 9 tons GVM. Also includes vehicles in class 'LR'.
- HR- A Heavy Rigid 'Class HR' covers a rigid vehicle with 3 or more axles and a GVM of more than 15 tons. Any towed trailer must not weigh more than 9 tons GVM. Also includes articulated buses and vehicles in class 'MR'.
- HC (Heavy Combination)- A 'Class HC' Licence covers heavy combination vehicles like a prime mover towing a semi-trailer, or rigid vehicles towing a trailer with a GVM of more than 9 tons. Also includes vehicles in class 'HR'.
- MC (Multi Combination)- A 'Class MC' Licence covers multi-combination vehicles like Road Trains and B-Double Vehicles. Also includes vehicles in class 'HC'.
New Zealand
In New Zealand drivers of heavy vehicles require specific licences, termed as 'classes'. A Class 1 Drivers Licence (aka a Car License) will allow the driving of any vehicle with Gross Laden Weight (GLW) or Gross Combination Weight (GCW) of 4500 kg or less. For other types of vehicles the Classes are separately licensed as follows:
- `Class 2 - Medium Rigid Vehicle' - Any rigid vehicle with GLW less than 18,001 kg (with Light Trailer up to 3500 kg or less), any combination vehicle with GCW less than 12,001 kg, any rigid vehicle of any weight with no more than 2 axles, or any Class 1 vehicle.
- 'Class 3 - Medium Combination Vehicle' - Any combination vehicle of GCW less than 25,001 kg or any Class 2 vehicle.
- 'Class 4 - Heavy Rigid Vehicle' - Any rigid vehicle of any weight, any Combination vehicle which consists of a heavy vehicle and a light trailer, or any vehicle of Class 1 or 2 (but not 3).
- 'Class 5 - Heavy Combination Vehicle' - Any combination vehicle of any weight, and any vehicle covered by previous classes.
- 'Class 6' is a Motorcycle Licence.
Further information on the New Zealand Licensing system for Heavy Vehicles can be found at
Land Transport New Zealand.
Role in industry
Modern day
semi-trailerA semi-trailer is a trailer without a front axle. A large proportion of its weight is supported by a road tractor, a detachable front axle assembly known as a dolly, or the tail of another trailer...
truckA truck or lorry is a motor vehicle designed to transport cargo. Trucks vary greatly in size, power, and configuration, with the smallest being mechanically similar to an automobile...
s often operate as a part of a domestic or international
transportTransport or transportation is the movement of people, cattle, animals and goods from one location to another. Modes of transport include air, rail, road, water, cable, pipeline, and space. The field can be divided into infrastructure, vehicles, and operations...
infrastructure to support
containerizedContainerization is a system of freight transport based on a range of steel intermodal containers...
cargoCargo is goods or produce transported, generally for commercial gain, by ship, aircraft, train, van or truck. In modern times, containers are used in most intermodal long-haul cargo transport.-Marine:...
shipmentShipping has multiple meanings. It can be a physical process of transporting commodities and merchandise goods and cargo, by land, air, and sea. It also can describe the movement of objects by ship.Land or "ground" shipping can be by train or by truck...
.
Various types of rail
flat bed train carsA flatcar is a piece of railroad or railway rolling stock that consists of an open, flat deck on four or six wheels or a pair of trucks or bogies . The deck of the car can be wood or steel, and the sides of the deck can include pockets for stakes or tie-down points to secure loads...
are modified to hold the cargo trailer or container with wheels or without. This is called "
IntermodalIntermodal freight transport involves the transportation of freight in an intermodal container or vehicle, using multiple modes of transportation , without any handling of the freight itself when changing modes. The method reduces cargo handling, and so improves security, reduces damages and...
" or "piggy-back" or "piggyback". The system allows the cargo to switch from the highway to railway or vice versa with relative ease by using gantry cranes.
The large trailers pulled by a
tractor unitA tractor unit, prime mover , road tractor, or traction unit is a heavy-duty commercial vehicle within the large goods vehicle category, usually with a large displacement diesel engine, and several axles. The tractor unit serves as a method of moving trailers...
come in many styles, lengths, and shapes. Some common types are: vans, reefers, flatbeds, sidelifts and tankers. These trailers may be refrigerated, heated, ventilated, or pressurized, depending on climate and cargo. Some trailers have movable wheel axles that can be adjusted by moving them on a track underneath the trailer body and securing them in place with large
pinsA pin is a device used for fastening objects or material together. It is usually made of steel, or on occasion copper or brass. It is formed by drawing out a thin wire, sharpening the tip, and adding a head. Nails are related, but are typically larger....
. The purpose of this is to help adjust weight distribution over the various axles, to comply with local laws.
Television
- NBC ran two popular TV series about truck drivers in the 1970s featuring actor Claude Akins
Claude Marion Akins was an American actor with a long career on stage, screen and television.Powerful in appearance and voice, Akins could be counted on to play the clever tough guy, on the side of good or bad, in movies and television. He is best remembered as Sheriff Lobo in the 1970s TV series...
in major roles:
- 1960s TV series Cannonball
- Movin' On
Movin' On is an American drama series that ran for two seasons , between 1974 and 1976. It originally appeared on the NBC television network...
(1974–1976)
- B. J. and the Bear (1978–1981)
- Knight Rider, this American television show featured a semi-trailer truck called 'The Semi', operated by the Foundation for Law & Government (F.L.A.G.) as a mobile support facility for KITT. Also, in two episodes KITT faced off against an armored semi called Goliath.
- The Transformers
The Transformers is an animated television series depicting a war among giant robots who could transform into vehicles, other objects and animal-like forms. Written and recorded in America, the series was animated in Japan and South Korea...
, tractor-trailers appear in this 1980s cartoon as the Autobots' leader Optimus Prime (Convoy in Japanese version), their second-in-command Ultra MagnusUltra Magnus is the name of several fictional characters from the various Transformers storylines.-Transformers: Generation 1:The greatest Transformer of them all. A commander could want no finer a soldier than Ultra Magnus...
, and as the Stunticons' leader MotormasterMotormaster is the name of several fictional characters from the Transformers universe. Motormaster made his first appearance in the Marvel Transformers comic before appearing in the animated series. Other than in Transformers: War for Cybertron, Motormaster is the leader of the Stunticons, an...
(who considers himself Optimus Prime's rival for the title "King of the Road"). Optimus Prime returned in the 2007 film.
- Trick My Truck
Trick My Truck is an American reality television program that premiered on February 3, 2006 on Country Music Television. Created by Varuna Entertainment, the series features a group of vehicle fabricators known as the "Chrome Shop Mafia" who renovate the trucks of "deserving" drivers in response to...
, this CMT show features trucks getting 'tricked out' (overhauled)
- Ice Road Truckers
Ice Road Truckers is a documentary-style reality television series that premiered on History on June 17, 2007.-History:In 2000, History aired a 46-minute episode titled "Ice Road Truckers" as part of the Suicide Missions series...
, this History Channel show charts two months in the lives of six drivers who haul supplies to diamond mines and oil fields over frozen lakes that double as roads.
Films
- Duel, Steven Spielberg's 1971 film, features a Peterbilt
Peterbilt Motors Company is an American manufacturer of medium- and heavy-duty Class 5 through Class 8 trucks headquartered in Denton, Texas. Founded in 1939 Peterbilt operates manufacturing facilities in Denton, Texas , and Sainte-Thérèse, Quebec...
281 tanker truck as the villain
- Maximum Overdrive
Maximum Overdrive is a 1986 American action-horror-science fiction film written and directed by novelist Stephen King. The screenplay was inspired by and loosely based on King's short story, Trucks, which was included in King's first collection of short stories, Night Shift.Maximum Overdrive is...
, Stephen King's 1986 film, featured big rigs as its primary homicidal villains
- Smokey and the Bandit
Smokey and the Bandit is a 1977 American film starring Burt Reynolds, Sally Field, Jackie Gleason, Jerry Reed, Pat McCormick, Paul Williams, and Mike Henry. It inspired several other trucking films, including two sequels, Smokey and the Bandit II, and Smokey and the Bandit Part 3...
- Convoy, a 1978 film directed by Sam Peckinpah
David Samuel "Sam" Peckinpah was an American filmmaker and screenwriter who achieved prominence following the release of the Western epic The Wild Bunch...
, starring Kris KristoffersonKristoffer "Kris" Kristofferson is an American musician, actor, and writer. He is known for hits such as "Me and Bobby McGee", "For the Good Times", "Sunday Mornin' Comin' Down", and "Help Me Make It Through the Night"...
Music
- "Convoy
"Convoy" is a 1975 novelty song performed by C. W. McCall that became a number-one song on both the country and pop charts in the US. Written by McCall and Chip Davis, the song spent six weeks at number one on the country charts and one week at number one on the pop charts...
", a pop song by C.W. McCall spurred sales of CB radios, with an imaginary trucking story
- The eighteen-wheeled truck was immortalized in numerous country music
Country music is a popular American musical style that began in the rural Southern United States in the 1920s. It takes its roots from Western cowboy and folk music...
songs such as Dave DudleyDave Dudley , born David Darwin Pedruska, was an American country music singer best-known for his truck-driving country anthems of the 1960s and 1970s and his semi-slurred baritone. His signature song was "Six Days on the Road," and he is also remembered for "Vietnam Blues," "Truck Drivin'...
's "Six Days on the Road".
- The Thrash Metal
Thrash metal is a subgenre of heavy metal that is characterized usually by its fast tempo and aggression. Songs of the genre typically use fast percussive and low-register guitar riffs, overlaid with shredding-style lead work...
band, BigRig, was named after these trucks.
- Country song "Eighteen Wheels and a Dozen Roses" made popular in 1987 by singer/song writer Kathy Mattea
Video games
- Hard Truck
Hard Truck is a series of trucking simulators and racing video games published in the United States by ValuSoft. The series currently has three released installments, with a fourth to be released soon.- Hard Truck :...
(1998)
- Big Rigs: Over the Road Racing
Big Rigs: Over the Road Racing is a 2003 third-person racing video game developed by Stellar Stone and published by Activision Value for Microsoft Windows PC systems; in 2004, GameMill Publishing was instead chosen to distribute copies of the title...
(2003)
- Euro Truck Simulator
Euro Truck Simulator is a truck simulation game created by SCS Software, using OpenGL, set in continental Europe. The player can drive across a depiction of Europe, visiting its cities, picking up a variety of cargos, and delivering them.- Gameplay :...
- 18 Wheels of Steel series
18 Wheels of Steel is a series of trucking simulators published by ValuSoft and developed by SCS Software. The series currently has 8 installments...
- "MotorStorm
MotorStorm is a 2006 racing video game developed by Evolution Studios and published by Sony Computer Entertainment for the Sony PlayStation 3 computer entertainment system. First announced at E3 2005, the game was released in Japan on 14 December 2006 and the rest of the world in March 2007....
"
- "Motorstorm: Pacific Rift
MotorStorm: Pacific Rift is a racing video game by Evolution Studios and published by Sony Computer Entertainment for the PlayStation 3. It is the sequel to MotorStorm and is followed by MotorStorm: Arctic Edge for the PS2/PSP, and MotorStorm: Apocalypse...
"
- Rig 'n' Roll
Rig'n'Roll, acronymed RnR or R&R, is a Sandbox-style truck driving simulation and Adventure racing video game released on 27 November 2009 in Russia and during 2010 in the rest of the world. It simulates truck driving and management along with associated business strategic activities, and features...
(2009)
- Rigs Of Rods
Rigs of Rods is an open source, freeware, multi-simulation game which uses soft-body physics to simulate the motion and deformation of trucks. The game is built using a specific soft-body physics engine called Beam, which simulates a network of interconnected nodes and gives the ability to...
See also
- Air brake (road vehicle)
Air brakes are used in trucks, buses, trailers, and semi-trailers. George Westinghouse first developed air brakes for use in railway service. He patented a safer air brake on March 5, 1872. Originally designed and built for use on railroad train application, air brakes remain the exclusive systems...
- Articulated vehicle
An articulated vehicle is a vehicle which has a permanent or semi-permanent pivoting joint in its construction, allowing the vehicle to turn more sharply. There are many kinds of articulated vehicles, from heavy equipment to buses, trams and trains...
- Brake
A brake is a mechanical device which inhibits motion. Its opposite component is a clutch. The rest of this article is dedicated to various types of vehicular brakes....
- Bus
A bus is a road vehicle designed to carry passengers. Buses can have a capacity as high as 300 passengers. The most common type of bus is the single-decker bus, with larger loads carried by double-decker buses and articulated buses, and smaller loads carried by midibuses and minibuses; coaches are...
- Dolly (trailer)
A dolly is a small trailer that can be coupled to a truck or trailer so as to support a semi-trailer. The dolly is equipped with a fifth wheel to which the semi-trailer is coupled...
- Drayage
In the shipping industry and logistics, drayage is the transport of goods a short distance, often as part of a longer overall move. A drayage trip can typically be completed in a single work shift. The term drayage is also used for the fee paid for such services.The term originally meant "to...
- Dump truck
A dump truck is a truck used for transporting loose material for construction. A typical dump truck is equipped with a hydraulically operated open-box bed hinged at the rear, the front of which can be lifted up to allow the contents to be deposited on the ground behind the truck at the site of...
- Dial-a-truck
Dial-a-Truck is an electronic freight posting service serving North America. It was the first system of its kind and established in 1978....
- Hybrid vehicle
A hybrid vehicle is a vehicle that uses two or more distinct power sources to move the vehicle. The term most commonly refers to hybrid electric vehicles , which combine an internal combustion engine and one or more electric motors.-Power:...
- Containerization
Containerization is a system of freight transport based on a range of steel intermodal containers...
- Jackknifing
Jackknifing means the folding of an articulated vehicle such that it resembles the acute angle of a folding pocket knife. If a vehicle towing a trailer skids, the trailer can push it from behind until it spins round and faces backwards. This may be caused by equipment failure, improper braking, or...
- Loader crane
- Oversize/overweight load
In road transport, an oversize load is a load that exceeds the standard or ordinary legal size and/or weight limits for a specified portion of road, highway or other transport infrastructure, such as air freight or water freight. There are also load per axle limits...
- Progressive shifting
Progressive shifting is a technique for changing gears commonly practiced by drivers of semi-trailer trucks. It is meant to reduce fuel consumption — something very important for drivers who travel several hundred miles each day....
- Refrigerator truck
A refrigerator truck is a van or truck designed to carry perishable freight at specific temperatures. Like refrigerator cars, refrigerated trucks differ from simple insulated and ventilated vans , neither of which are fitted with cooling apparatus...
- Road train
A road train or roadtrain is a trucking concept used in remote areas of Argentina, Australia, Mexico, the United States and Canada to move freight efficiently. The term "road train" is most often used in Australia. In the U.S. and Canada the terms "triples," "turnpike doubles" and "Rocky Mountain...
- Semi-trailer
A semi-trailer is a trailer without a front axle. A large proportion of its weight is supported by a road tractor, a detachable front axle assembly known as a dolly, or the tail of another trailer...
- Shunt truck
A Shunt truck, also known as a Spotting tractor, Yard truck, Yard Dog, Yard jockey, mule, etc. is an articulated vehicle consisting of a towing engine , and a semi-trailer hitch to carry the freight...
- Tank truck
A tank truck or road tanker is a motor vehicle designed to carry liquefied loads, dry bulk cargo or gases on roads. The largest such vehicles are similar to railroad tank cars which are also designed to carry liquefied loads...
- Tractor unit
A tractor unit, prime mover , road tractor, or traction unit is a heavy-duty commercial vehicle within the large goods vehicle category, usually with a large displacement diesel engine, and several axles. The tractor unit serves as a method of moving trailers...
- Trailer (vehicle)
A trailer is generally an unpowered vehicle pulled by a powered vehicle. Commonly, the term trailer refers to such vehicles used for transport of goods and materials....
- Trailer bus
A trailer bus or articulated trailer bus is a bus formed out of a bus bodied semi-trailer pulled by a conventional tractor unit in the same way as a conventional articulated semi-trailer truck....
- Train
A train is a connected series of vehicles for rail transport that move along a track to transport cargo or passengers from one place to another place. The track usually consists of two rails, but might also be a monorail or maglev guideway.Propulsion for the train is provided by a separate...
- Truck
A truck or lorry is a motor vehicle designed to transport cargo. Trucks vary greatly in size, power, and configuration, with the smallest being mechanically similar to an automobile...
- Truck driver
A truck driver , is a person who earns a living as the driver of a truck, usually a semi truck, box truck, or dump truck.Truck drivers provide an essential service to...
External links
- TruckNetUK.com, dedicated to Trucking Information in UK and Europe
- Ol' Blue, USA, Safety and Education in and around big trucks in the US as well as an AskTheLaw section also in print and on radio where questions can be directed to commercial law enforcement