Editing Tractor (section)

== Applications and variations ==

=== Farm ===
[[File:JDTractor chisel-plough.jpg|thumb|left|A modern [[Deere & Company|John Deere]] 8110 Farm Tractor plowing a field using a [[chisel plow]]]]
[[File:Farmer and tractor tilling soil.jpg|thumb|A tractor pulling a tiller]]

The most common use of the term "tractor" is for the [[vehicle]]s used on [[farm]]s. The farm tractor is used for pulling or pushing [[agriculture|agricultural]] machinery or [[Trailer (vehicle)|trailer]]s, for [[plow]]ing, tilling, disking, harrowing, planting, and similar tasks.

[[File:TractorPoweringWaterpump.jpg|thumb|A farm tractor used to power a [[pump]] for [[irrigating]] a plot of land]]

A variety of specialty farm tractors have been developed for particular uses.  These include "row crop" tractors with adjustable tread width to allow the tractor to pass down rows of [[cereals]], [[maize]], [[tomatoes]] or other crops without crushing the plants, "wheatland" or "standard" tractors with fixed wheels and a lower center of gravity for plowing and other heavy field work for broadcast crops, and "high crop" tractors with adjustable tread and increased ground clearance, often used in the cultivation of cotton and other high-growing row crop plant operations, and "utility tractors", typically smaller tractors with a low center of gravity and short turning radius, used for general purposes around the farmstead. Many utility tractors are used for nonfarm grading, [[landscape maintenance]] and excavation purposes, particularly with loaders, backhoes, pallet forks and similar devices.  Small garden or [[lawn mowers|lawn tractor]]s designed for suburban and semirural gardening and landscape maintenance are produced in a variety of configurations, and also find numerous uses on a farmstead.

[[File:Ueberladewagen (jha).jpg|thumb|right|A tractor with an [[auger wagon]]]]

Some farm-type tractors are found elsewhere than on farms: with large universities' gardening departments, in public parks, or for highway workman use with [[blowtorch]] cylinders strapped to the sides and a [[Jackhammer|pneumatic drill]] [[air compressor]] permanently fastened over the [[power take-off]]. These are often fitted with grass (turf) tyres which are less damaging to soft surfaces than agricultural tires.

==== Precision ====
[[Space technology]] has been incorporated into [[agriculture]] in the form of [[GPS]] devices, and robust on-board [[computers]] installed as optional features on farm tractors. These technologies are used in modern, [[precision farming]] techniques. The [[Government spin-off|spin-off]]s from the [[space race]] have actually facilitated [[automation]] in plowing and the use of autosteer systems ([[Unmanned ground vehicle|drone]] on tractors that are manned but only steered at the end of a row), the idea being to neither overlap and use more fuel nor leave streaks when performing jobs such as [[Agriculture|cultivating]]. Several tractor companies have also been working on producing a [[driverless tractor]].

=== Engineering ===
[[File:Chelyabinsk tractor factory 1930s.jpg|thumb|A tractor factory in [[Chelyabinsk]] in the [[Soviet Union]] circa 1930]]
[[File:tractor fanguejant.jpg|thumb|[[Ebro trucks|Ebro]] farm tractor with steel wheel extensions.  This arrangement is often used in muddy conditions that are found in paddy farming of rice.]]

The durability and engine power of tractors made them very suitable for engineering tasks. Tractors can be fitted with engineering tools such as [[bulldozer|dozer blade]]s, [[loader (equipment)|bucket]]s, [[hoe (equipment)|hoe]]s, rippers, etc.  The most common attachments for the front of a tractor are dozer blades or buckets. When attached to engineering tools, the tractor is called an [[engineering vehicle]].

A [[bulldozer]] is a [[tractor crawler|track-type tractor]]  with a blade attached in the front and a rope-winch behind. Bulldozers are very powerful tractors and have excellent ground-hold, as their main tasks are to push or drag.

Bulldozers have been further modified over time to evolve into new machines which are capable of working in ways that the original bulldozer can not. One example is that [[Loader (equipment)|loader]] tractors were created by removing the blade and substituting a large volume bucket and hydraulic arms which can raise and lower the bucket, thus making it useful for scooping up earth, rock and similar loose material to load it into trucks.

A front-loader or loader is a tractor with an engineering tool which consists of two hydraulic powered arms on either side of the front engine compartment and a tilting implement. This is usually a wide-open box called a bucket, but other common attachments are a [[pallet fork]] and a bale grappler.

Other modifications to the original bulldozer include making the machine smaller to let it operate in small work areas where movement is limited. Also, tiny wheeled loaders, officially called [[skid-steer loader]]s, but nicknamed "[[Bobcat (equipment)|Bobcat]]" after the original manufacturer, are particularly suited for small excavation projects in confined areas.

=== Backhoe ===
{{Main|Backhoe loader}}
[[File:Backhoe and loader.jpg|thumb|A common [[Case Corporation|Case]] [[backhoe loader]], with backhoe on the rear and loader bucket in front]]

The most common variation of the classic farm '''tractor''' is the '''backhoe''', also called a '''backhoe-loader'''. As the name implies, it has a loader assembly on the front and a [[backhoe]] on the back. Backhoes attach to a three-point hitch on farm or industrial tractors.  Industrial tractors are often heavier in construction, particularly with regards to the use of a steel grill for protection from rocks and the use of construction tires. When the backhoe is permanently attached, the machine usually has a seat that can swivel to the rear to face the [[Hoe (tool)|hoe]] controls. Removable backhoe attachments almost always have a separate seat on the attachment.

Backhoe-loaders are very common and can be used for a wide variety of tasks: construction, small demolitions, light transportation of building materials, powering building equipment, digging holes, loading trucks, breaking [[Asphalt concrete|asphalt]] and paving roads. Some buckets have retractable bottoms, enabling them to empty their loads more quickly and efficiently. Buckets with retractable bottoms are also often used for grading and scratching off sand. The front assembly may be a removable attachment or permanently mounted. Often the bucket can be replaced with other devices or tools.

Their relatively small frames and precise controls make backhoe-loaders very useful and common in [[civil engineering|urban engineering]] projects, such as construction and [[repair]]s in areas too small for larger equipment. Their versatility and compact size make them one of the most popular urban [[construction vehicle]]s.

In the UK and Ireland, the word "[[J. C. Bamford|JCB]]" is used [[colloquial]]ly as a [[genericized trademark]] for any such type of engineering vehicle. The term JCB now appears in the [[Oxford English Dictionary]], although it is still legally a [[trademark]] of J. C. Bamford Ltd. The term "digger" is also commonly used.

=== Compact utility ===
[[File:Farm Tractor vs CUT vs Garden Tractor.jpg|thumb|left|The relative sizes of a {{cvt|30|hp|kW}} [[Oliver Farm Equipment Company|Oliver]] Super 55 farm tractor, a {{cvt|24|hp|kW}} diesel New Holland [[compact utility tractor]], and a Cub Cadet [[lawn tractor]]]]

A compact utility tractor (CUT) is a smaller version of an agricultural tractor, but designed primarily for landscaping and estate management tasks, rather than for planting and harvesting on a commercial scale. Typical CUTs range from {{cvt|20-50|hp|kW}} with available [[power take-off]] (PTO) power ranging from {{cvt|15-45|hp|kW}}. CUTs are often equipped with both a mid-mounted and a standard rear PTO, especially those below {{cvt|40|hp|kW}}. The mid-mount PTO shaft typically rotates at/near 2000 rpm and is typically used to power mid-mount finish mowers, front-mounted [[snow blower]]s or front-mounted rotary brooms.  The rear PTO is standardized at 540 [[rpm]] for the North American markets, but in some parts of the world, a dual 540/1000 rpm PTO is standard, and implements are available for either standard in those markets.

[[File:1subsoil1.jpg|thumb|right|Howse brand modular [[Bulldozer#Ripper|subsoiler]] mounted to a tractor]]
[[File:Herd Seeder.jpeg|thumb|right|Broadcast seeder mounted to a [[Kubota]] CUT]]

One of the most common attachments for a CUT is the [[front-end loader]] or FEL. Like the larger agricultural tractors, a CUT will have an adjustable, hydraulically controlled [[three-point hitch]]. Typically, a CUT will have four-wheel drive, or more correctly four-wheel assist. Modern CUTs often feature hydrostatic transmissions, but many variants of gear-drive transmissions are also offered from low priced, simple gear transmissions to synchronized transmissions to advanced glide-shift transmissions. All modern CUTs feature government-mandated [[roll over protection structure]]s just like agricultural tractors. The most well-known brands in North America include [[Kubota Corporation|Kubota]], [[John Deere Tractor]], [[New Holland Ag]], Case-Farmall and Massey Ferguson.  Although less common, compact backhoes are often attached to compact utility tractors.

[[File:JD 71 Flexi Planter, 2 Row.jpg|thumb|left|JD 71 Flexi [[Planter (farm implement)|Planter]] for tractors {{convert|20-50|hp|kW}}]]

Compact utility tractors require special, smaller implements than full-sized agricultural tractors.  Very common implements include the [[box blade]], the [[grader]] blade, the landscape rake, the post hole digger (or post hole [[auger (drill)|auger]]), the rotary cutter (slasher or a brush hog), a mid- or rear-mount finish mower, a [[broadcast seeder]], a [[subsoiler]] and the [[rototiller]] (rotary tiller).  In northern climates, a rear-mounted snow blower is very common; some smaller CUT models are available with front-mounted snow blowers powered by mid-PTO shafts. Implement brands outnumber tractor brands, so CUT owners have a wide selection of implements.

For small-scale farming or large-scale gardening, some planting and harvesting implements are sized for CUTs. One- and two-row planting units are commonly available, as are cultivators, sprayers and different types of seeders (slit, rotary and drop).  One of the first CUTs offered for small farms of three to 30 acres and for small jobs on larger farms was a three-wheeled unit, with the rear wheel being the drive wheel, offered by [[Sears & Roebuck]] in 1954 and priced at $598 for the basic model.<ref>[https://books.google.com/books?id=1t4DAAAAMBAJ&pg=PA96 "Three Wheeled Tractor With Implements Handles Small-Farm Work."] ''Popular Mechanics'', June 1954, p. 96.</ref>

An even smaller variant of the compact utility tractor is the ''subcompact utility tractor''. Although these tractors are often barely larger than a [[riding lawn mower]], these tractors have all the same features of a compact tractor, such as a three-point hitch, power steering, four-wheel-drive, and front-end loader. These tractors are generally marketed towards homeowners who intend to mostly use them for lawn mowing, with the occasional light landscaping task.<ref>{{cite web | url=https://tractorexport.com/compact-and-subcompact-tractors-compared/ | title=Compact and Sub-Compact Tractors Compared | date=30 June 2017 }}</ref><ref>{{cite web | url=https://www.tractorbynet.com/forums/threads/almost-daily-thread-subcompact-or-compact-tractor.411509/ | title=Tractor Sizing – Almost Daily Thread: Subcompact  or Compact Tractor? | date=22 April 2019 }}</ref><ref>{{cite web | url=https://www.youtube.com/watch?v=xhnhaS9Krdc | title=Kubota BX Series VS. B Series | website=[[YouTube]] | date=5 July 2017 }}</ref>

=== Standard ===
The earliest tractors were called "standard" tractors, and were intended almost solely for [[plough|plowing]] and [[harrow (tool)|harrowing]] before planting, which were difficult tasks for humans and [[working animal|draft animals]]. They were characterized by a low, rearward seating position, fixed-width tread, and low ground clearance. These early tractors were cumbersome, and ill-suited to enter a field of planted row crops for weed control. The "standard" tractor definition is no longer in current use. However, tractors with fixed wheel spacing and a low center of gravity are well-suited as loaders, forklifts and backhoes, so that the configuration continues in use without the "standard" nomenclature.

=== Row-crop ===
{{Redirect|Row-crop|row-crop production generally|Row crop|and|Market garden}}

A '''general-purpose''' or '''row-crop tractor''' is tailored specifically to the growing of crops grown in rows, and most especially to [[cultivator|cultivating]] these crops. These tractors are universal machines, capable of both [[tillage|primary tillage]] and cultivation of a crop. 
<!-- relevant? out of place?
"Row crop" refers to any farm [[crop]] cultivated in rows. The [[United States Environmental Protection Agency]] (EPA) defines row crop as an "[a]gricultural crop planted, usually with mechanical planting devices, in individual rows that are spaced to permit machine traffic during the early parts of the growing season".<ref>{{cite web|url=http://www.epa.gov/oecaagct/ag101/cropglossary.html |title=Crop Glossary &#124; Ag 101 &#124; Agriculture &#124; US EPA |publisher=Epa.gov |date=2006-06-28 |access-date=2010-07-29}}</ref>-->

[[File:Farmall regular web.JPG|thumb|A [[Farmall]] "Regular"]]

The row-crop tractor category evolved rather than appearing overnight, but the [[International Harvester]] (IH) [[Farmall]] is often considered the "first" tractor of the category. Some earlier tractors of the 1910s and 1920s approached the form factor from the heavier side, as did motorized cultivators from the lighter side, but the Farmall brought all of the salient features together into one package, with a capable distribution network to ensure its commercial success. In the new form factor that the Farmall popularized, the [[cultivator]] was mounted in the front so it was easily visible. Additionally, the tractor had a narrow front end; the front tires were spaced very closely and angled in toward the bottom. The back wheels straddled two rows with their spacing adjustable depending on row spacing, and the unit could cultivate four rows at once. Where wide front wheels were used, they often could be adjusted as well. Tractors with non-adjustable spacing were called "standard" or "wheatland", and were chiefly meant for pulling plows or other towed implements, typically with a lower overall tractor height than row-crop models.

From 1924 until 1963, Farmalls were the largest selling row-crop tractors.

To compete, [[John Deere]] designed the [[List of John Deere tractors|Model C]], which had a wide front and could cultivate three rows at once. Only 112 prototypes were made, as Deere realized it would lose sales to Farmall if its model did less. In 1928, Deere released the Model C anyway, only as the [[Model GP]] (General Purpose) to avoid confusion with the Model D when ordered over the then unclear telephone.<ref name="KlancherLeffingwellMorland2003}"/>

Oliver refined its "Row Crop" model early in 1930.<ref>{{cite web |url=http://www.livinghistoryfarm.org/farminginthe30s/machines_04.html |title=Tractors Advance during the Depression |publisher=Livinghistoryfarm.org |access-date=2010-07-29 |archive-date=2021-02-22 |archive-url=https://web.archive.org/web/20210222033224/http://www.livinghistoryfarm.org/farminginthe30s/machines_04.html |url-status=dead }}</ref> Until 1935, the 18–27 was Oliver–[[Hart-Parr]]'s only row-crop tractor.<ref name="Ertel2001p72"/>

Many Oliver row-crop models are referred to as "Oliver Row Crop 77", "Oliver Row Crop 88", etc.

Many early row-crop tractors had a tricycle design with two closely spaced front tires, and some even had a single front tire. This made it dangerous to operate on the side of a steep hill; as a result, many farmers died from tractor rollovers. Also, early row-crop tractors had no [[rollover protection system]] (ROPS), meaning if the tractor flipped back, the operator could be crushed. Sweden was the first country which passed legislation requiring ROPS, in 1959.

Over 50% of tractor related injuries and deaths are attributed to tractor [[Vehicle rollover|rollover]].<ref name="Donham, K. 1999"/>

Canadian agricultural equipment manufacturer [[Versatile (company)|Versatile]] makes row-crop tractors that are {{convert|265|to|365|hp|kW}}; powered by an 8.9 liter [[Cummins Diesel]] engine.<ref>{{Cite web|url=https://cumminsengines.com/showcase-item.aspx?id=110&title=QSL9+for+Agriculture+(Tier+4+Interim)&|title=QSL9 for Agriculture (Tier 4 Interim)|website=Cummins Engines|language=en|access-date=2018-06-11}}</ref><ref>{{Cite web|url=https://www.versatile-ag.com/NA/pages/product_mfwd.php|title=Versatile – MFWD Tractors|website=www.versatile-ag.com|language=en|access-date=2018-06-11}}</ref>

[[Case IH]] and [[New Holland Agriculture|New Holland]] of [[CNH Industrial]] both produce high horsepower front-wheel-assist row crop tractors with available rear tracks.<ref>{{Cite web|url=http://agriculture1.newholland.com/nar/en-us/equipment/products/tractors-telehandlers/genesis-t8-series-tier-4b|title=GENESIS® T8 Series – Tier 4B – Overview {{!}} Tractors ＆ Telehandlers {{!}} New Holland (US)|website=agriculture1.newholland.com|language=en|access-date=2018-06-11}}</ref>  Case IH also has a {{cvt|500|hp}} four-wheel drive track system called Rowtrac.<ref>{{Cite web|url=https://www.caseih.com/northamerica/en-us/Pages/campaigns/track-leadership.aspx|title=Track Technology {{!}} Quadtrac and Rowtrac Tractors {{!}} Case IH|website=Case IH|language=en-US|access-date=2018-06-11}}</ref>

[[John Deere]] has an extensive line of available row crop tractors ranging from {{convert|140|to|400|hp}}.<ref>{{Cite web|url=https://www.deere.com/en/tractors/row-crop-tractors/|title=John Deere Tractors {{!}} Row Crop Tractors {{!}} John Deere US|website=www.deere.com|language=en|access-date=2018-06-11}}</ref>

Modern row crop tractors have rollover protection systems in the form of a reinforced cab or a [[roll cage|roll bar]].

=== Garden ===
[[File:Benin brown tractor 600.jpg|thumb|A [[garden tractor]] towing a cargo cart]]

Garden tractors, sometimes called lawn tractors, are small, light tractors designed for use in domestic [[garden]]s, lawns, and small estates. Lawn tractors are designed for cutting [[grass]] and snow removal, while garden tractors are for small property cultivation. In the U.S., the term [[Lawn mower#Riding (ride-on) mowers|riding lawn mower]] today often is used to refer to mid- or rear-engined machines. Front-engined tractor layout machines designed primarily for cutting grass and light towing are called [[lawn tractors]]; heavier-duty tractors of similar size are garden tractors. Garden tractors are capable of mounting a wider array of attachments than lawn tractors. Unlike lawn tractors and rear-engined riding mowers, garden tractors are powered by horizontal-crankshaft engines with a [[Belt (mechanical)|belt]]-drive to [[transaxle]]-type transmissions (usually of four or five speeds, although some may also have two-speed reduction gearboxes, drive-shafts, or hydrostatic or [[Hydrokinetic transmission|hydraulic drives]]). Garden tractors from [[Wheel Horse]], [[Cub Cadet]], [[Economy (Power King)]], John Deere, [[Massey Ferguson]] and Case [[Ingersoll Power Equipment|Ingersoll]] are built in this manner. The engines are generally one- or two-cylinder petrol (gasoline) engines, although [[diesel engine]] models are also available, especially in Europe. Typically, diesel-powered garden tractors are larger and heavier-duty than gasoline-powered units and compare more similarly to compact utility tractors.

Visually, the distinction between a garden tractor and a lawn tractor is often hard to make – generally, garden tractors are more sturdily built, with stronger frames, 12-inch or larger wheels mounted with multiple lugs (most lawn tractors have a single bolt or clip on the hub), heavier transaxles, and ability to accommodate a wide range of front, belly, and rear mounted attachments.

=== Two-wheel ===
{{main|Two-wheel tractor}}
Although most people think primarily of four-wheel vehicles when they think of tractors, a tractor may have one or more axles. The key benefit is the power itself, which only takes one axle to provide. Single-axle tractors, more often called [[two-wheel tractor]]s or walk-behind tractors, have had many users since the introduction of the [[internal combustion engine]] tractors. They tend to be small and affordable, this was especially true before the 1960s when a walk-behind tractor could often be more affordable than a two-axle tractor of comparable power. Today's compact utility tractors and advanced garden tractors may negate most of that market advantage, but two-wheel tractors still have a following, especially among those who already own one. Countries where two-wheel tractors are especially prevalent today include [[Thailand]], [[China]], [[Bangladesh]], [[India]], and other [[Southeast Asia]] countries. Most two-wheel tractors today are specialty tractors made for one purpose, such as [[snow blower]]s, [[Cultivator|push tillers]], and [[Lawn mower|self propelled push mowers]].

=== Orchard ===
Tractors tailored to use in fruit [[orchard]]s typically have features suited to passing under tree branches with impunity. These include a lower overall profile; reduced tree-branch-snagging risk (via underslung exhaust pipes rather than smoke-stack-style exhaust, and large sheetmetal [[cowling]]s and [[:wikt:fairing|fairing]]s that allow branches to deflect and slide off rather than catch); [[spark arrestor]]s on the exhaust tips; and often wire cages to protect the operator from snags.

=== Automobile conversions and other homemade versions===
[[File:Model T tractor.png|thumb|A [[Model T]] tractor pulling a plow]]
[[File:Pullford auto-to-tractor conversion advert 1918.png|thumb|left|An advertisement for auto-to-tractor conversion kits, 1918]]
[[File:Ford epa tractor.jpg|thumb|A Ford rebuilt to an EPA tractor]]
[[File:Duett-EPA-rear.jpg|thumb|left|A Volvo Duett rebuilt to an EPA tractor. The intended use is no longer as a farm vehicle.]]
[[File:Volvo at Power Big Meet 2005.jpg|thumb|A " tractor" based on [[Volvo 760]] – notice the smv triangle and the longer boot.]]

The ingenuity of farm mechanics, coupled in some cases with [[original equipment manufacturer|OEM]] or [[aftermarket (automotive)|aftermarket]] assistance, has often resulted in the conversion of automobiles for use as farm tractors. In the United States, this trend was especially strong from the 1910s through 1950s. It began early in the development of vehicles powered by internal combustion engines, with blacksmiths and amateur mechanics tinkering in their shops. Especially during the [[interwar period]], dozens of manufacturers ([[Montgomery Ward]] among them) marketed aftermarket kits for converting [[Ford Model T]]s for use as tractors.<ref name="PrippsMorland1993p28"/> (These were sometimes called 'Hoover wagons' during the [[Great Depression]], although this term was usually reserved for [[Bennett buggy|automobiles converted to horse-drawn buggy use]] when gasoline was unavailable or unaffordable.  During the same period, another common name was "[[Doodlebug tractor|Doodlebug]]", after the popular kit by the same name.) Ford even considered producing an "official" optional kit.<ref name="Leffingwell2004p43-53"/> Many [[Ford Model A (1927–1931)|Model A Fords]] also were converted for this purpose. In later years, some farm mechanics have been known to convert more modern trucks or cars for use as tractors, more often as curiosities or for recreational purposes (rather than out of the earlier motives of pure necessity or frugality).

{{Anchor|EPA tractors in Sweden}}
During [[World War&nbsp;II]], a shortage of tractors in [[Sweden]] led to the development of the so-called "EPA" tractor ([[:sv:EPA (varuhus)|EPA]] was a chain of discount stores and it was often used to signify something lacking in quality). An EPA tractor was simply an automobile, truck or lorry, with the passenger space cut off behind the front seats, equipped with two gearboxes in a row. When done to an older car with a [[ladder frame]], the result was similar to a tractor and could be used as one.  After the war it remained popular as a way for young people without a [[driver's license]] to own something similar to a car. Since it was legally seen as a tractor, it could be driven from 16 years of age and only required a tractor license. Eventually, the legal loophole was closed and no new EPA tractors were allowed to be made, but the remaining ones were still legal, which led to inflated prices and many protests from people who preferred EPA tractors to ordinary cars.

The Swedish government eventually replaced them with the so called "A-tractor" which now had its speed limited to 30&nbsp;km/h and allowed people aged 16 and older to drive the cars with a moped license.

The German occupation of Italy during World {{nowrap|War II}} resulted in a severe shortage of mechanized farm equipment.  The destruction of tractors was a sort of [[scorched earth|scorched-earth]] strategy used to reduce the independence of the conquered.  The shortage of tractors in that area of Europe was the origin of [[History of Lamborghini#Origin|Lamborghini]].  The war was also the inspiration for dual-purpose vehicles such as the [[Land Rover]].  Based on the Jeep, the company made a vehicle that combined PTO, tillage, 4wd, and transportation.

In March 1975, a similar type of vehicle was introduced in Sweden, the ''A tractor'' [from ''arbetstraktor'' (work tractor)]; the main difference is an A tractor has a top speed of 30&nbsp;km/h. This is usually done by fitting two gearboxes in a row and only using one. The [[Volvo Duett]] was, for a long time, the primary choice for conversion to an EPA or A tractor, but since supplies have dried up, other cars have been used, in most cases another [[Volvo Cars|Volvo]]. The [[SFRO]] is a Swedish organization advocating homebuilt and modified vehicles.

Another type of homemade tractors are ones that are [[fabrication (metal)|fabricated]] from scratch. The "[[wikt:from scratch#Adverb|from scratch]]" description is relative, as often individual components will be repurposed from earlier vehicles or machinery (e.g., engines, gearboxes, axle housings), but the tractor's overall [[chassis]] is essentially designed and built by the owner (e.g., a frame is welded from [[bar stock]]{{snd}}channel stock, angle stock, flat stock, etc.). As with automobile conversions, the heyday of this type of tractor, at least in developed economies, lies in the past, when there were large populations of blue-collar workers for whom [[metalworking]] and [[farming]] were prevalent parts of their lives. (For example, many 19th- and 20th-century [[New England]] and [[Midwestern United States|Midwestern]] machinists and factory workers had grown up on farms.) Backyard fabrication was a natural activity to them (whereas it might seem daunting to most people today).

=== Nomenclature ===
The term "tractor" (US and Canada) or "tractor unit" (UK) is also applied to:
* '''Road tractors''', '''[[tractor unit]]s''' or traction heads, familiar as the front end of an [[articulated lorry]] / [[semi-trailer truck]]. They are heavy-duty [[vehicle]]s with large [[engine]]s and several [[axle]]s.
** The majority of these tractors are designed to pull long [[semi-trailer]]s, most often to transport freight over a significant distance, and is connected to the trailer with a [[fifth wheel coupling]]. In England, this type of "tractor" is often called an "[[Semi-trailer truck|artic cab]]" (short for "articulated" cab).
** A minority is the [[ballast tractor]], whose load is hauled from a [[Drawbar (haulage)|drawbar]].
* '''[[Pushback (aviation)|Pushback tractors]]''' are used on airports to move aircraft on the ground, most commonly pushing aircraft away from their parking stands.
* [[Locomotive]] tractors ([[engine]]s) or [[rail car mover]]s – the amalgamation of [[machine]]s, [[electrical generator]]s, controls and devices that comprise the [[traction component]] of [[railway]] [[vehicle]]s
* [[Artillery tractor]]s – vehicles used to tow [[artillery]] pieces of varying weights.
* [[NASA]] and [[list of space agencies|other space agencies]] use [[Crawler-transporter|very large tractors]] to move large [[launch vehicle]]s and [[Space Shuttle]]s between their hangars and [[launch pad]]s.
* A [[pipe-tractor]] is a device used for conveying advanced instruments into pipes for measurement and data logging, and the purging of well holes, sewer pipes and other inaccessible tubes.
<gallery class="center" caption="Non-agricultural tractors">
File:UP Diesel.png|Diesel-electric [[locomotive]] at work
File:Trackmobile.jpg|A Trackmobile 4150
File:Tractor-powered Roadroller.jpg|A tractor-driven [[road roller]]
File:Airplane pushing vehicle.jpg|Aircraft [[Pushback (aviation)|pushback tractor]]
File:Backing it in 2.jpg|Road tractor pulling a flatbed trailer
File:Mercedes-Benz-Museum 2015-01 by-RaBoe 187.jpg|[[Unimog 70200]]
File:Tractor for hauling logs, Maine IMG 2036.JPG|A [[Lombard Steam Log Hauler|Lombard steam log hauler]]
</gallery>