digplanet beta 1: Athena
Share digplanet:

Agriculture

Applied sciences

Arts

Belief

Business

Chronology

Culture

Education

Environment

Geography

Health

History

Humanities

Language

Law

Life

Mathematics

Nature

People

Politics

Science

Society

Technology

Peterbilt 386 cab style tractor unit
A Leyland T45 cab-over tractor unit

A tractor unit, semi tractor (U.S.), prime mover (Australian English), road tractor, or traction unit is typically a heavy-duty military tractor or commercial freight vehicle within the large goods vehicle category, though medium duty models are made. Tractor units typically have large displacement diesel engines for power, durability, and economy, and several axles for maximum flexibility in gearing.

A tractor unit's function it to pull trailers (most often semi-trailers). Different trailers performing different functions, such as a bulk tipper and box trailer, or containing differing cargos can be rapidly swapped between tractors, eliminating downtime while a trailer is unloaded or loaded.

The tractor-trailer combination also distributes a load across multiple axles while being more maneuverable than an equivalently sized rigid truck. The most common trailer attachment system is a fifth wheel coupling.

In the USA and Australia in particular, owner drivers, and even fleet operators, go to great lengths to customise their tractors. This often involves liberal chrome plating, fitting larger exhaust systems and extra lights, and custom paint. Customized tractors are sometimes mated with matching trailers.

Configurations[edit]

Cab[edit]

There have been three common cab configurations used in tractors, two are still widely used. The conventional has an engine and hood over the front axle in front of the cab, as in most automobiles. This style is almost universal in the North America. The cab over engine has a flat nose cab with the driver sitting in front of the front axle. Widely used in the EU, this style has the advantages of good vision, maneuverability, and allows maximum trailer length relative to overall length. In the North America this type of cab can be useful in strait trucks, but now has little advantage in tractors and is rarely used. A North American style cab over engine, now largely obsolete, had a flat nose cab located higher over the engine, with the driver sitting above the front axle. This allowed a sleeper compartment in a short tractor, and maximum wheelbase relative overall length, important for bridge formula weight restrictions. With the loosening of length restrictions in 1982 this style had limited applications, and is no longer manufactured in the U.S.[1][2][3][4][5][6]

Axle[edit]

A tractor unit can have many axles depending on axle load legislation. The most common varieties are those of 4x2, 6x2 and 6x4 types[a]. However, some manufacturers offer 6x6, 8x6, 8x8, 10x8, and 10x10 axle configurations. A 6x4 has three axles, with two of the axles driven. 6x4 units are more common in long distance haulage in larger countries such as the USA and Australia. In Europe, the 4x2 and 6x2 variants are more commonplace.

Tractors with three axles or more can have more than one steering axle, which can also be driven. Most 6x2 units allow the undriven rear axle to be raised when lightly loaded, or running without a trailer, to save tyre wear, and increase traction. The 6x6 units have three axles, all driven, and 8x6 units have four axles, with the rear three usually driven and the front axle for steering. The 8x8 units also have four axles, but with all of them driven, and 10x8 units have five axles with the rear four usually driven and the front axle for steering. All five axles of 10x10 units are driven. The front two axles are usually both steer axles. The axle configurations are usually based on axle load legislation, and maximum gross vehicle weight ratings (BDM).

Heavier versions of tractor units, such as those used in heavy haulage and road trains, tend to have four or more axles, with more than two axles driven. In certain countries (such as Switzerland), a certain amount of weight must be spread over driven axles, which lead to heavier varieties having six-wheel drive, otherwise another tractor unit would have to be used. Heavy haulage variants of tractor-units are often turned into a ballast tractor by fitting temporary ballast, which may require special permitting.[1][2][7]

See also[edit]

References[edit]

  1. ^ a b "Freight Management and Operations: Bridge Formula Weights". U.S. Department of Transportation. Retrieved 25 June 2013. 
  2. ^ a b "Freight Management and Operations: Size Regulations". U.S. Department of Transportation. Retrieved 25 Jun 2013. 
  3. ^ "International Trucks (U.S.)". Navistar, Inc. 2013. Retrieved 25 June 2013. 
  4. ^ "Mack Trucks (U.S.)". Mack Trucks, Inc. 2013. Retrieved 25 June 2013. 
  5. ^ "Mercedes-Benz Truck (Germany)". Daimler AG. 2013. Retrieved 25 June 2013. 
  6. ^ "Volvo Trucks (Worldwide)". AB Volvo. Retrieved 25 June 2013. 
  7. ^ "Guidelines on Maximum Weights…Criteria (EU)". Road Safety Authority. 2013. Retrieved 25 June 2013. 

Notes[edit]

  1. ^ Total wheels X driven wheels, with 2 wheels per axle regardless of single or dual tires.

Original courtesy of Wikipedia: http://en.wikipedia.org/wiki/Tractor_unit — Please support Wikipedia.
This page uses Creative Commons Licensed content from Wikipedia. A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia.
365828 videos foundNext > 

SCANIA R480 6X4 DOUBLE DRIVE TRACTOR UNIT

MAN XXL truck tractor unit for sale via Ebay with mikeedge7

MAN tractor unit for sale via E bay with mikeedge7.

Копаем руду с Mobile Tractor Unit и пару слов о Mobile Depot.

EVE Online Тестим новый модуль который появился с патчем Рубикон. Копаем, выкидываем в космос, а Mobile Tractor Unit подтягивает и лутает. А так же пару слов...

Mobile Tractor Units - Rubicon

Subscribe for more EVE Online videos ▻ http://goo.gl/5UD6wY Follow Me on Google+ ▻ http://goo.gl/r81ejF Like Me on Facebook ▻ http://goo.gl/M1usVf Follow Me ...

Mobile Tractor Unit in Level 4 missions - EVE Online

Trying out the new Mobile Tractor Unit in a Level 4 mission. It's quite a handy tool that makes salvaging and collecting wreck loot a breeze. EVE Online Rubicon.

Mercedes Benz New Actros Tractor Unit 6x6 building report Final Part Ligth and Sound Test

Bitte immer in HD ansehen! See the Video in HD please! This is the last Video from Building the Actros! The next Videos with this Model will be in Action! ;-...

EVE Online • Mobile Tractor Unit Cleanup

Subscribe for more EVE Online videos ▻ http://goo.gl/5UD6wY Follow Me on Google+ ▻ http://goo.gl/r81ejF Like Me on Facebook ▻ http://goo.gl/M1usVf Follow Me ...

Эксплоит Mobile Tractor Unit

EVE Online Видео о том как слить карибаса используя странную механику игры. Обсудить можно здесь: https://forums.eveonline.com/default.aspx?g=posts&t=310015.

EVE Online: Salvaging with the Mobile Tractor Unit - How real men salvage.

With the release of Rubicon came the new deployable Mobile Tractor Unit. It has a tractor beam range of 120km and will bring in wrecks to automatically loot ...

2012 MAN TGX 26.440 Tractor Unit Inside view etc

I'm revving this sonovabitch for You boys. 440 HP diesel power YAAA truck 2012 MAN Tractor Unit TGX 26.440 Inside look etc Some revving etc.

365828 videos foundNext > 

1032 news items

GlobeNewswire (press release)

GlobeNewswire (press release)
Tue, 17 Feb 2015 11:41:15 -0800

Notes to editors: SmartWay trailer fuel savings assume that the trailer is used with a fully aerodynamic profile, high-roof tractor unit with an integrated roof fairing and side fairings. A SmartWay trailer is a dry van trailer that can achieve a fuel ...

eMercedesBenz

eMercedesBenz
Fri, 13 Feb 2015 12:03:45 -0800

Work on the Actros and semitrailer took about seven weeks, since there were a few tasks to complete, particularly on the tractor unit, before the entire rig could be turned into a rolling canvas. Even though the base colour was already white in this ...

Irish Independent

Irish Independent
Tue, 24 Feb 2015 05:11:18 -0800

He said he had called the guards, but they had so far been unable to trace the lorry, which he said travelled at least 20 feet along the pavement before coming to rest. Tony said it was a grey tractor unit, with a Carlow registration plate, and a white ...
 
Lancashire Telegraph
Mon, 23 Feb 2015 22:00:00 -0800

The vehicles are also compact in size compared with a standard tractor unit and trailer. This allows them easier access to the locations where recycling banks are most commonly positioned, such as supermarket car parks or retail parks, which can often ...

CranesY.com - Crazy about cranes

CranesY.com - Crazy about cranes
Sun, 08 Feb 2015 23:14:20 -0800

The 135 txm Effer 2055 articulated crane in the video was delivered and mounted on an 8×4 Mercedes 4155 tractor unit by our partner in the UK, Effer Atlas, and it stands out among an extensive fleet of loader and articulated cranes used in the company ...

Tyrepress.com

Tyrepress.com
Wed, 04 Feb 2015 04:00:00 -0800

Its vehicles range from 7.5 tonne rigids to 44 tonne tractor unit and trailer combinations, with the busiest vehicles travelling up to 180,000 km a year. Hermes UK works with some of the UK's leading brands, including Tesco, John Lewis and the Arcadia ...

Waste Management World

Waste Management World
Fri, 06 Feb 2015 05:59:33 -0800

The trailer is supplied and operated by FODSA and once full, FODSA use a Renault Kerax 6x4 tractor unit to bring an empty waste transfer trailer to the waste transfer station so the loading of fresh waste can restart. The full waste transfer trailer is ...

Irish Trucker Magazine

Irish Trucker Magazine
Fri, 06 Feb 2015 01:33:45 -0800

... Control with Predictive Shifting and Eco Mode, fuel savings of at least 5% are achievable. The CF tractor unit with a rear steering axle is available with the Day Cab, Sleeper Cab and Space Cab; the XF is available with the Space Cab and Super ...
Loading

Oops, we seem to be having trouble contacting Twitter

Support Wikipedia

A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia. Please add your support for Wikipedia!

Searchlight Group

Digplanet also receives support from Searchlight Group. Visit Searchlight