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A tractor is an engineering vehicle specifically designed to deliver a high tractive effort (or torque) at slow speeds, for the purposes of hauling a trailer or machinery such as that used in agriculture, mining or construction. Most commonly, the term is used to describe a farm vehicle that provides the power and traction to
mechanize ''Mechanize'' is the seventh studio album by American heavy metal band Fear Factory. It is the only album to feature Gene Hoglan on drums and the first since 2001's '' Digimortal'' to include original guitarist and founding member Dino Cazares, ...
agricultural tasks, especially (and originally) tillage, and now many more. Agricultural implements may be towed behind or mounted on the tractor, and the tractor may also provide a source of power if the implement is mechanised.


Etymology

The word ''tractor'' was taken from Latin, being the
agent noun In linguistics, an agent noun (in Latin, ) is a word that is derived from another word denoting an action, and that identifies an entity that does that action. For example, "driver" is an agent noun formed from the verb "drive". Usually, ''derive ...
of ''trahere'' "to pull". The first recorded use of the word meaning "an engine or vehicle for pulling wagons or plows" occurred in 1896, from the earlier term " traction motor" (1859).


National variations

In the UK, Ireland,
Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
, India, Spain, Argentina, Slovenia, Serbia, Croatia, the Netherlands, and Germany, the word "tractor" usually means "farm tractor", and the use of the word "tractor" to mean other types of vehicles is familiar to the vehicle trade, but unfamiliar to much of the general public. In Canada and the US, the word may also refer to the
road tractor A tractor unit (also known as a truck unit, power unit, prime mover, ten-wheeler, semi-tractor, tractor truck, semi-truck, tractor cab, truck cab, tractor rig, truck rig or big rig or simply a tractor, truck, semi or rig) is a characteristical ...
portion of a tractor trailer truck, but also usually refers to the piece of farm equipment.


History


Traction engines

The first powered farm implements in the early 19th century were
portable engine A portable engine is an engine, either a steam engine or an internal combustion engine, that sits in one place while operating (providing power to machinery), but (unlike a stationary engine) is wikt:portable#Adjective, portable and thus can be ...
s – steam engines on wheels that could be used to drive mechanical farm machinery by way of a flexible belt. Richard Trevithick designed the first 'semi-portable'
stationary steam engine Stationary steam engines are fixed steam engines used for pumping or driving mills and factories, and for power generation. They are distinct from locomotive engines used on railways, traction engines for heavy steam haulage on roads, steam cars ...
for agricultural use, known as a "barn engine" in 1812, and it was used to drive a corn threshing machine. The truly portable engine was invented in 1893 by
William Tuxford William is a male given name of Germanic origin.Hanks, Hardcastle and Hodges, ''Oxford Dictionary of First Names'', Oxford University Press, 2nd edition, , p. 276. It became very popular in the English language after the Norman conquest of Engl ...
of Boston, Lincolnshire who started manufacture of an engine built around a locomotive-style boiler with horizontal smoke tubes. A large flywheel was mounted on the crankshaft, and a stout leather belt was used to transfer the drive to the equipment being driven. In the 1850s, John Fowler used a Clayton & Shuttleworth portable engine to drive apparatus in the first public demonstrations of the application of cable haulage to cultivation. In parallel with the early portable engine development, many engineers attempted to make them self-propelled – the fore-runners of the traction engine. In most cases this was achieved by fitting a sprocket on the end of the crankshaft, and running a chain from this to a larger sprocket on the rear axle. These experiments met with mixed success. The first proper traction engine, in the form recognisable today, was developed in 1859 when British engineer Thomas Aveling modified a Clayton & Shuttleworth
portable engine A portable engine is an engine, either a steam engine or an internal combustion engine, that sits in one place while operating (providing power to machinery), but (unlike a stationary engine) is wikt:portable#Adjective, portable and thus can be ...
, which had to be hauled from job to job by horses, into a self-propelled one. The alteration was made by fitting a long driving chain between the crankshaft and the rear axle. The first half of the 1860s was a period of great experimentation but by the end of the decade the standard form of the traction engine had evolved and changed little over the next sixty years. It was widely adopted for agricultural use. The first tractors were steam-powered plowing engines. They were used in pairs, placed on either side of a field to haul a plow back and forth between them using a wire cable. In Britain Mann's and Garrett developed steam tractors for direct ploughing, but the heavy, wet soil of England meant that these designs were less economical than a team of horses. In the United States, where soil conditions permitted, steam tractors were used to direct-haul plows. Steam-powered agricultural engines remained in use well into the 20th century until reliable internal combustion engines had been developed.


Gasoline

The first gasoline powered tractors were built in Illinois, by John Charter combining single cylinder Otto engines with a Rumley Steam engine chasis, in 1889. In 1892, John Froelich built a gasoline-powered tractor in Clayton County, Iowa, US. A Van Duzen single-cylinder gasoline engine was mounted on a Robinson engine chassis, which could be controlled and propelled by Froelich's gear box. After receiving a patent, Froelich started up the Waterloo Gasoline Engine Company and invested all of his assets. The venture was very unsuccessful, and by 1895 all was lost and he went out of business. Richard Hornsby & Sons are credited with producing and selling the first oil-engined tractor in Britain, invented by Herbert Akroyd Stuart. The Hornsby-Akroyd Patent Safety Oil Traction Engine was made in 1896 with a engine. In 1897, it was bought by Mr. Locke-King, the first recorded British tractor sale. That year, it won a Silver Medal from the Royal Agricultural Society of England. It later returned to the factory for a caterpillar track fitting. The first commercially successful light-weight petrol-powered general purpose tractor was built by Dan Albone, a British inventor in 1901. He filed for a patent on 15 February 1902 for his tractor design and then formed Ivel Agricultural Motors Limited. The other directors were Selwyn Edge, Charles Jarrott, John Hewitt and
Lord Willoughby Baron Willoughby of Parham was a title in the Peerage of England with two creations. The first creation was for Sir William Willoughby who was raised to the peerage under letters patent in 1547, with the remainder to his heirs male of body. A ...
. He called his machine the Ivel Agricultural Motor; the word "tractor" came into common use after Hart-Parr created it. The Ivel Agricultural Motor was light, powerful and compact. It had one front wheel, with a solid rubber tyre, and two large rear wheels like a modern tractor. The engine used water cooling, utilizing the thermo-syphon effect. It had one forward and one reverse gear. A pulley wheel on the left hand side allowed it to be used as a
stationary engine A stationary engine is an engine whose framework does not move. They are used to drive immobile equipment, such as pumps, generators, mills or factory machinery, or cable cars. The term usually refers to large immobile reciprocating engines, pr ...
, driving a wide range of agricultural machinery. The 1903 sale price was £300. His tractor won a medal at the Royal Agricultural Show, in 1903 and 1904. About 500 were built, and many were exported all over the world. The original engine was made by Payne & Co. of Coventry. After 1906, French
Aster Aster or ASTER may refer to: Biology * ''Aster'' (genus), a genus of flowering plants ** List of ''Aster'' synonyms, other genera formerly included in ''Aster'' and still called asters in English * Aster (cell biology), a cellular structure shap ...
engines were used. The first successful American tractor was built by Charles W. Hart and Charles H. Parr. They developed a two-cylinder gasoline engine and set up their business in
Charles City, Iowa Charles City is a city in and the county seat of Floyd County, Iowa. Charles City is a significant commercial and transportation center for the area. U.S. Routes 18 and 218, Iowa Highway 14, and the Canadian National and Canadian Pacific railr ...
. In 1903, the firm built 15 tractors. Their #3 is the oldest surviving internal combustion engine tractor in the United States, and is on display at the Smithsonian National Museum of American History in Washington, D.C. The two-cylinder engine has a unique hit-and-miss firing cycle that produced at the belt and at the drawbar. In 1908, the Saunderson Tractor and Implement Co. of Bedford introduced a four-wheel design, and became the largest tractor manufacturer in Britain at the time. While the earlier, heavier tractors were initially very successful, it became increasingly apparent at this time that the weight of a large supporting frame was less efficient than lighter designs. Henry Ford introduced a light-weight, mass-produced design which largely displaced the heavier designs. Some companies halfheartedly followed suit with mediocre designs, as if to disprove the concept, but they were largely unsuccessful in that endeavor. While unpopular at first, these gasoline-powered machines began to catch on in the 1910s, when they became smaller and more affordable. Henry Ford introduced the Fordson, a wildly popular mass-produced tractor, in 1917. They were built in the U.S., Ireland, England and Russia, and by 1923, Fordson had 77% of the U.S. market. The Fordson dispensed with a frame, using the strength of the engine block to hold the machine together. By the 1920s, tractors with gasoline-powered internal combustion engines had become the norm. The first three-point hitches were experimented with in 1917. After
Harry Ferguson Henry George "Harry" Ferguson (4 November 188425 October 1960) was a British mechanic and inventor who is noted for his role in the development of the modern agricultural tractor and its three point linkage system, for being the first person ...
applied for a British patent for his three-point hitch in 1926, they became popular. A three-point attachment of the implement to the tractor and the simplest and the only statically determinate way of joining two bodies in engineering. The Ferguson-Brown Company produced the Model A Ferguson-Brown tractor with a Ferguson-designed hydraulic hitch. In 1938 Ferguson entered into a collaboration with Henry Ford to produce the Ford-Ferguson 9N tractor. The three-point hitch soon became the favorite hitch attachment system among farmers around the world. This tractor model also included a rear Power Take Off (PTO) shaft that could be used to power three point hitch mounted implements such as sickle-bar mowers.


Design, power and transmission


Configuration

Tractors can be generally classified by number of axles or wheels, with main categories of two-wheel tractors (single-axle tractors) and four-wheel tractors (two-axle tractors); more axles are possible but uncommon. Among four-wheel tractors (two-axle tractors), most are two-wheel drive (usually at the rear); but many are two-wheel drive with front wheel assist, four-wheel drive (often with articulated steering), or
track Track or Tracks may refer to: Routes or imprints * Ancient trackway, any track or trail whose origin is lost in antiquity * Animal track, imprints left on surfaces that an animal walks across * Desire path, a line worn by people taking the shorte ...
crawler (with steel or rubber tracks). The classic farm tractor is a simple open vehicle, with two very large driving wheels on an axle below a single seat (the seat and steering wheel consequently are in the center), and the engine in front of the driver, with two steerable wheels below the engine compartment. This basic design has remained unchanged for a number of years after being pioneered by Wallis, but enclosed cabs are fitted on almost all modern models, for operator safety and comfort. In some localities with heavy or wet soils, notably in the Central Valley of California, the "Caterpillar" or "crawler" type of tracked tractor became popular due to superior traction and flotation. These were usually maneuvered through the use of turning brake pedals and separate track clutches operated by levers rather than a steering wheel. Four-wheel drive tractors began to appear in the 1960s. Some four-wheel drive tractors have the standard "two large, two small" configuration typical of smaller tractors, while some have four large, powered wheels. The larger tractors are typically an articulated, center-hinged design steered by hydraulic cylinders that move the forward power unit while the trailing unit is not steered separately. In the early 21st century, articulated or non-articulated, steerable multitrack tractors have largely supplanted the Caterpillar type for farm use. Larger types of modern farm tractors include articulated four-wheel or eight-wheel drive units with one or two power units which are hinged in the middle and steered by hydraulic clutches or pumps. A relatively recent development is the replacement of wheels or steel crawler-type tracks with flexible, steel-reinforced rubber tracks, usually powered by hydrostatic or completely hydraulic driving mechanisms. The configuration of these tractors bears little resemblance to the classic farm tractor design.


Engine and fuels

The predecessors of modern tractors, traction engines, used
steam engine A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be trans ...
s for power.


Gasoline and kerosene

Since the turn of the 20th century, internal combustion engines have been the power source of choice. Between 1900 and 1960, gasoline was the predominant fuel, with kerosene (the Rumely Oil Pull was the most notable of this kind)being a common alternative. Generally, one engine could burn any of those, although cold starting was easiest on gasoline. Often, a small auxiliary fuel tank was available to hold gasoline for cold starting and warm-up, while the main fuel tank held whatever fuel was most convenient or least expensive for the particular farmer. In the United Kingdom, a gasoline-kerosene engine is known as a petrol-paraffin engine.


Diesel

Dieselisation gained momentum starting in the 1960s, and modern farm tractors usually employ diesel engines, which range in power output from 18 to 575 horsepower (15 to 480 kW). Size and output are dependent on application, with smaller tractors used for
lawn mowing A lawn mower (also known as a mower, grass cutter or lawnmower) is a device utilizing one or more revolving blades (or a reel) to cut a grass surface to an even height. The height of the cut grass may be fixed by the design of the mower, but g ...
, landscaping, orchard work, and truck farming, and larger tractors for vast fields of wheat, corn, soy, and other bulk crops.


Liquefied petroleum gas

Liquefied petroleum gas Liquefied petroleum gas (LPG or LP gas) is a fuel gas which contains a flammable mixture of hydrocarbon gases, specifically propane, propylene, butylene, isobutane and n-butane. LPG is used as a fuel gas in heating appliances, cooking e ...
(LPG) or
propane Propane () is a three-carbon alkane with the molecular formula . It is a gas at standard temperature and pressure, but compressible to a transportable liquid. A by-product of natural gas processing and petroleum refining, it is commonly used a ...
also have been used as tractor fuels, but require special pressurized fuel tanks and filling equipment and produced less power, so are less prevalent in most markets.


Wood

During the second world war, Petrolium based fuel was scarce in many European nations. So they resorted to using wood gasifires on every vehicle, including tractors.


Biodiesel

In some countries such as Germany, biodiesel is often used. Some other biofuels such as straight vegetable oil are also being used by some farmers.


Electric powered

Prototype battery powered
electric tractors Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by ...
are being developed by a German company, Fendt, and by two US companies, Solectrac and Monarch Tractor.
John Deere Deere & Company, doing business as John Deere (), is an American corporation that manufactures agricultural machinery, heavy equipment, forestry machinery, diesel engines, drivetrains (axles, transmissions, gearboxes) used in heavy equipment, ...
's protoype electric tractor is a plug-in, powered by an electrical cable. Kubota is prototyping an autonomous electric tractor.


Transmission

Most older farm tractors use a manual transmission with several gear ratios, typically three to six, sometimes multiplied into two or three ranges. This arrangement provides a set of discrete ratios that, combined with the varying of the throttle, allow final-drive speeds from less than one up to about 25 miles per hour (40 km/h), with the lower speeds used for working the land and the highest speed used on the road. Slow, controllable speeds are necessary for most of the operations performed with a tractor. They help give the farmer a larger degree of control in certain situations, such as field work. When travelling on public roads, the slow operating speeds can cause problems, such as long queues or tailbacks, which can delay or annoy motorists in cars and trucks. These motorists are responsible for being duly careful around farm tractors and sharing the road with them, but many shirk this responsibility, so various ways to minimize the interaction or minimize the speed differential are employed where feasible. Some countries (for example the Netherlands) employ a road sign on some roads that means "no farm tractors". Some modern tractors, such as the
JCB JCB may refer to: * JCB (company), a British manufacturer of heavy industrial and agricultural vehicles * JCB Co., Ltd., originally Japan Credit Bureau, a credit card company based in Tokyo, Japan * JCB Prize, a literary award sponsored by the c ...
Fastrac, are now capable of much higher road speeds of around 50 mph (80 km/h). Older tractors usually have unsynchronized transmission designs, which often require the operator to engage the clutch to shift between gears. This mode of use is inherently unsuited to some of the work tractors do, and has been circumvented in various ways over the years. For existing unsynchronized tractors, the methods of circumvention are double clutching or power-shifting, both of which require the operator to rely on skill to speed-match the gears while shifting, and are undesirable from a risk-mitigation standpoint because of what can go wrong if the operator makes a mistake – transmission damage is possible, and loss of vehicle control can occur if the tractor is towing a heavy load either uphill or downhill – something that tractors often do. Therefore, operator's manuals for most of these tractors state one must always stop the tractor before shifting. In newer designs, unsynchronized transmission designs were replaced with
synchronization Synchronization is the coordination of events to operate a system in unison. For example, the conductor of an orchestra keeps the orchestra synchronized or ''in time''. Systems that operate with all parts in synchrony are said to be synchronou ...
or with
continuously variable transmission A continuously variable transmission (CVT) is an automatic transmission that can change seamlessly through a continuous range of gear ratios. This contrasts with other transmissions that provide a limited number of gear ratios in fixed steps. T ...
s (CVTs). Either a synchronized manual transmission with enough available gear ratios (often achieved with dual ranges, high and low) or a CVT allow the engine speed to be matched to the desired final-drive speed, while keeping engine speed within the appropriate speed (as measured in rotations per minute or rpm) range for power generation (the working range) (whereas throttling back to achieve the desired final-drive speed is a trade-off that leaves the working range). The problems, solutions, and developments described here also describe the history of transmission evolution in semi-trailer trucks. The biggest difference is fleet turnover; whereas most of the old
road tractor A tractor unit (also known as a truck unit, power unit, prime mover, ten-wheeler, semi-tractor, tractor truck, semi-truck, tractor cab, truck cab, tractor rig, truck rig or big rig or simply a tractor, truck, semi or rig) is a characteristical ...
s have long since been scrapped, many of the old farm tractors are still in use. Therefore, old transmission design and operation is primarily just of historical interest in trucking, whereas in farming it still often affects daily life.


Hitches and power applications

The power produced by the engine must be transmitted to the implement or equipment to do the actual work intended for the equipment. This may be accomplished via a drawbar or hitch system if the implement is to be towed or otherwise pulled through the tractive power of the engine, or via a pulley or power takeoff system if the implement is stationary, or a combination of the two.


Drawbars

Plows and other tillage equipment are most commonly connected to the tractor via a drawbar. The classic drawbar is simply a steel bar attached to the tractor (or in some cases, as in the early Fordsons, cast as part of the rear transmission housing) to which the hitch of the implement was attached with a pin or by a loop and clevis. The implement could be readily attached and removed, allowing the tractor to be used for other purposes on a daily basis. If the tractor was equipped with a swinging drawbar, then it could be set at the center or offset from center to allow the tractor to run outside the path of the implement. The drawbar system necessitated the implement having its own running gear (usually wheels) and in the case of a plow, chisel cultivator or harrow, some sort of lift mechanism to raise it out of the ground at turns or for transport. Drawbars necessarily posed a rollover risk depending on how the tractive torque was applied. The Fordson tractor (of which more units were produced and placed in service than any other farm tractor) was prone to roll backward due to an excessively short wheelbase. The linkage between the implement and the tractor usually had some slack which could lead to jerky starts and greater wear and tear on the tractor and the equipment. Drawbars were appropriate to the dawn of mechanization, because they were very simple in concept and because as the tractor replaced the horse, existing horse-drawn implements usually already had running gear. As the history of mechanization progressed, the advantages of other hitching systems became apparent, leading to new developments (see below). Depending on the function for which a tractor is used, though, the drawbar is still one of the usual means of attaching an implement to a tractor (see photo at left).


Fixed mounts

Some tractor manufacturers produced matching equipment that could be directly mounted on the tractor. Examples included front-end loaders, belly mowers, row crop cultivators, corn pickers and corn planters. In most cases, these fixed mounts were proprietary and unique to each make of tractor, so an implement produced by John Deere, for example, could not be attached to a Minneapolis Moline tractor. Another disadvantage was mounting usually required some time and labor, resulting in the implement being semi-permanently attached with bolts or other mounting hardware. Usually, it was impractical to remove the implement and reinstall it on a day-to-day basis. As a result, the tractor was unavailable for other uses and dedicated to a single use for an appreciable period of time. An implement was generally mounted at the beginning of its season of use (such as tillage, planting or harvesting) and removed when the season ended.


Three-point and quick

The drawbar system was virtually the exclusive method of attaching implements (other than direct attachment to the tractor) before
Harry Ferguson Henry George "Harry" Ferguson (4 November 188425 October 1960) was a British mechanic and inventor who is noted for his role in the development of the modern agricultural tractor and its three point linkage system, for being the first person ...
developed the three-point hitch. Equipment attached to the three-point hitch can be raised or lowered hydraulically with a control lever. The equipment attached to the three-point hitch is usually completely supported by the tractor. Another way to attach an implement is via a quick hitch, which is attached to the three-point hitch. This enables a single person to attach an implement quicker and put the person in less danger when attaching the implement. The three-point hitch revolutionized farm tractors and their implements. While the Ferguson system was still under patent, other manufacturers developed new hitching systems to try to fend off some of Ferguson's competitive advantage. For example, International Harvester's Farmall tractors gained a two-point "Fast Hitch", and John Deere had a power lift that was somewhat similar to the more flexible Ferguson invention. Once the patent protection expired on the three-point hitch, it became an industry standard. Almost every tractor today features Ferguson's three-point linkage or a derivative of it. This hitch allows for easy attachment and detachment of implements while allowing the implement to function as a part of the tractor, almost as if it were attached by a fixed mount. Previously, when the implement hit an obstacle, the towing link broke or the tractor flipped over. Ferguson's idea was to combine a connection via two lower and one upper lift arms that were connected to a hydraulic lifting ram. The ram was, in turn, connected to the upper of the three links so the increased drag (as when a plough hits a rock) caused the hydraulics to lift the implement until the obstacle was passed. Recently, Bobcat's patent on its front loader connection (inspired by these earlier systems) has expired, and compact tractors are now being outfitted with quick-connect attachments for their
front-end loaders A loader is a heavy equipment machine used in construction to move or load materials such as soil, rock, sand, demolition debris, etc. into or onto another type of machinery (such as a dump truck, conveyor belt, feed-hopper, or railroad ca ...
.


Power take-off systems and hydraulics

In addition to towing an implement or supplying tractive power through the wheels, most tractors have a means to transfer power to another machine such as a
baler A baler or hay baler is a piece of farm machinery used to compress a cut and raked crop (such as hay, cotton, flax straw, salt marsh hay, or silage) into compact bales that are easy to handle, transport, and store. Often, bales are configured ...
,
swather A swather (North America), or windrower (Australia and rest of world), is a farm implement that cuts hay or small grain crops and forms them into a windrow for drying. They may be self-propelled with an engine, or drawn by a tractor and po ...
, or mower. Unless it functions solely by pulling it through or over the ground, a towed implement needs its own power source (such as a baler or combine with a separate engine) or else a means of transmitting power from the tractor to the mechanical operations of the equipment. Early tractors used belts or cables wrapped around the flywheel or a separate belt pulley to power stationary equipment, such as a threshing machine, buzz saw, silage blower, or stationary baler. In most cases, it was impractical for the tractor and equipment to move with a flexible belt or cable between them, so this system required the tractor to remain in one location, with the work brought to the equipment, or the tractor to be relocated at each turn and the power set-up reapplied (as in cable-drawn plowing systems used in early steam tractor operations). Modern tractors use a
power take-off A power take-off or power takeoff (PTO) is one of several methods for taking power from a power source, such as a running engine, and transmitting it to an application such as an attached implement or separate machine. Most commonly, it is a sp ...
(PTO) shaft to provide rotary power to machinery that may be stationary or pulled. The PTO shaft generally is at the rear of the tractor, and can be connected to an implement that is either towed by a drawbar or a three-point hitch. This eliminates the need for a separate, implement-mounted power source, which is almost never seen in modern farm equipment. It is also optional to get a front PTO as well when buying a new tractor. Virtually all modern tractors can also provide external
hydraulic fluid A hydraulic fluid or hydraulic liquid is the medium by which power is transferred in hydraulic machinery. Common hydraulic fluids are based on mineral oil or water. Examples of equipment that might use hydraulic fluids are excavators and backhoe ...
and electrical power to the equipment they are towing, either by hoses or wires.


Operation

Modern tractors have many electrical switches and levers in the cab for controlling the multitude of different functions available on the tractor.


Pedals

Some modern farm tractors retain a traditional manual transmission; increasingly they have hydraulically driven powershift
transmission Transmission may refer to: Medicine, science and technology * Power transmission ** Electric power transmission ** Propulsion transmission, technology allowing controlled application of power *** Automatic transmission *** Manual transmission *** ...
s and CVT, which vastly simplify operation. Those with powershift transmissions have identical pedal arrangements on the floor for the operator to actuate, replacing a
clutch A clutch is a mechanical device that engages and disengages power transmission, especially from a drive shaft to a driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts). ...
pedal on the far left with an inching pedal that cuts off hydraulic flow to the clutches. Twinned
brake A brake is a mechanical device that inhibits motion by absorbing energy from a moving system. It is used for slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by means of friction. Background ...
pedals - one each for left and right side wheels- are placed together on the right side. Some have a pedal for a foot throttle on the far right. Unlike automobiles, throttle speed can also be controlled by a hand-operated lever ("hand throttle"), which may be set to a fixed position. This helps provide a constant speed in field work. It also helps provide continuous power for stationary tractors that are operating an implement by PTO shaft or axle driven belt. The foot throttle gives the operator more automobile-like control over the speed of a mobile tractor in any operation. Some modern tractors also have (or offer as optional equipment) a button on the gear stick for controlling the clutch, in addition to the standard pedal, allowing for gear changes and the tractor to be brought to a stop without using the foot pedal to engage the clutch. Others have a button for temporarily increasing throttle speed to improve hydraulic flow to implements, such as a front end loader bucket. Independent left and right brake pedals are provided to allow improved steering (by engaging the side one wishes to turn to, slowing or stopping its wheel) and improved traction in soft and slippery conditions (by transferring rotation to the wheel with better grip). Some users prefer to lock both pedals together, or utilize a partial lock that allows the left pedal to be depressed independently but engages both when the right is applied. This may be in the form of a swinging or sliding bolt that may be readily engaged or disengaged in the field without tools. Foot pedal throttle control is mostly a returning feature of newer tractors. In the UK, foot pedal use to control engine speed while travelling on the road is mandatory. Some tractors, especially those designed for row-crop work, have a 'de-accelerator' pedal, which operates in the reverse fashion of an automobile throttle, slowing the engine when applied. This allows control over the speed of a tractor with its throttle set high for work, as when repeatedly slowing to make U-turns at the end of crop rows in fields. A front-facing foot button is traditionally included just ahead of the driver's seat (designed to be pressed by the operator's heel) to engage the rear differential lock (diff-lock), which prevents wheel slip. The differential normally allows driving wheels to operate at their own speeds, as required, for example, by the different radius each takes in a turn. This allows the outside wheel to travel faster than the inside wheel, thereby traveling further during a turn. In low-traction conditions on a soft surface, the same mechanism can allow one wheel to slip, wasting its torque and further reducing traction. The differential lock overrides this, forcing both wheels to turn at the same speed, reducing wheel slip and improving traction. Care must be taken to unlock the differential before turning, usually by hitting the pedal a second time, since the tractor with good traction cannot perform a turn with the diff-lock engaged. In many modern tractors, this pedal is replaced with an electrical switch.


Levers and switches

Many functions once controlled with levers have been replaced with some model of electrical switch with the rise of indirect computer controlling of functions in modern tractors. Until the late of the 1950s, tractors had a single register of gears, hence one gear stick, often with three to five forward gears and one reverse. Then, group gears were introduced, and another gear stick was added. Later, control of the forward-reverse direction was moved to a special stick attached at the side of the steering wheel, which allowed forward or reverse travel in any gear. Now, with CVTs or other gear types, fewer sticks control the transmission, and some are replaced with electrical switches or are totally computer-controlled. The three-point hitch was controlled with a lever for adjusting the position, or as with the earliest ones, just the function for raising or lowering the hitch. With modern electrical systems, it is often replaced with a potentiometer for the lower bound position and another one for the upper bound, and a switch allowing automatic adjustment of the hitch between these settings. The external hydraulics also originally had levers, but now are often replaced with some form of electrical switch; the same is true for the
power take-off A power take-off or power takeoff (PTO) is one of several methods for taking power from a power source, such as a running engine, and transmitting it to an application such as an attached implement or separate machine. Most commonly, it is a sp ...
shaft.


Safety

Agriculture in the United States is one of the most hazardous industries, only surpassed by mining and construction. No other farm machine is so identified with the
hazard A hazard is a potential source of harm Harm is a moral and legal concept. Bernard Gert construes harm as any of the following: * pain * death * disability * mortality * loss of abil ity or freedom * loss of pleasure. Joel Feinberg giv ...
s of production agriculture as the tractor. Tractor-related injuries account for approximately 32% of the fatalities and 6% of the nonfatal injuries in agriculture. Over 50% is attributed to tractor overturns.Donham, K., D. Osterberg, M.L. Meyers, and C. Lehtola. 1999. Final report tractor risk abatement and control: the policy conference, September 10–12, 1997. The University of Iowa, Iowa City, Iowa. The
roll-over protection structure A rollover protection structure or rollover protection system (ROPS) ( or ) is a system or structure intended to protect equipment operators and motorists from injuries caused by vehicle overturns or rollovers. Like rollcages and rollbars in ca ...
(ROPS) and seat belt, when worn, are the most important safety devices to protect operators from death during tractor overturns. Modern tractors have a ROPS to prevent an operator from being crushed when overturning. This is especially important in open-air tractors, where the ROPS is a steel beam that extends above the operator's seat. For tractors with operator cabs, the ROPS is part of the frame of the cab. A ROPS with enclosed cab further reduces the likelihood of serious injury because the operator is protected by the sides and windows of the cab. These structures were first required by legislation in Sweden in 1959. Before they were required, some farmers died when their tractors rolled on top of them. Row-crop tractors, before ROPS, were particularly dangerous because of their 'tricycle' design with the two front wheels spaced close together and angled inward toward the ground. Some farmers were killed by rollovers while operating tractors along
steep Steep may refer to: Arts and entertainment * ''Steep'' (2007 film), a film about extreme skiing * ''Steep'' (video game), a 2016 video game Places England * Steep, Hampshire, a village in central Hampshire, England * Steep Hill, a popular to ...
slopes. Others have been killed while attempting to tow or pull an excessive load from above axle height, or when cold weather caused the tires to freeze to the ground, in both cases causing the tractor to pivot around the rear axle. ROPS were first required in the United States in 1986, non-retroactively. ROPS adoption by farmers is thus incomplete. To treat this problem, CROPS (cost-effective roll-over protection structures) have been developed to encourage farmers to retrofit older tractors. For the ROPS to work as designed, the operator must stay within its protective frame and wear the seat belt. In addition to ROPS, U.S. manufacturers add instructional seats on tractors with enclosed cabs. The tractors have a ROPS with seatbelts for both the operator and passenger. This instructional seat is intended to be used for training new tractor operators, but can also be used to diagnose machine problems. The misuse of an instructional seat increases the likelihood of injury, especially when children are transported. The International Organization for Standardization’s ISO standard 23205:2014 specifies the minimum design and performance requirements for an instructional seat and states that the instructional seat is neither intended for, nor is it designed for use by children. Despite this, upwards of 40% of farm families give their children rides on tractors, often using these instructional seats.


Applications and variations


Farm

The most common use of the term "tractor" is for the vehicles used on farms. The farm tractor is used for pulling or pushing
agricultural Agriculture or farming is the practice of cultivating Plant, plants and livestock. Agriculture was the key development in the rise of Sedentism, sedentary human civilization, whereby farming of Domestication, domesticated species created food ...
machinery or trailers, for
plow A plough or plow ( US; both ) is a farm tool for loosening or turning the soil before sowing seed or planting. Ploughs were traditionally drawn by oxen and horses, but in modern farms are drawn by tractors. A plough may have a wooden, iron or ...
ing, tilling, disking, harrowing, planting, and similar tasks. 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 tractor A lawn mower (also known as a mower, grass cutter or lawnmower) is a device utilizing one or more revolving blades (or a reel) to cut a grass surface to an even height. The height of the cut grass may be fixed by the design of the mower, but g ...
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. 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 pneumatic drill air compressor permanently fastened over the
power take-off A power take-off or power takeoff (PTO) is one of several methods for taking power from a power source, such as a running engine, and transmitting it to an application such as an attached implement or separate machine. Most commonly, it is a sp ...
. 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 The Global Positioning System (GPS), originally Navstar GPS, is a Radionavigation-satellite service, satellite-based radionavigation system owned by the United States government and operated by the United States Space Force. It is one of t ...
devices, and robust on-board
computers A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as programs. These programs ...
installed as optional features on farm tractors. These technologies are used in modern, precision farming techniques. The
spin-off Spin-off may refer to: *Spin-off (media), a media work derived from an existing work *Corporate spin-off, a type of corporate action that forms a new company or entity * Government spin-off, civilian goods which are the result of military or gove ...
s from the space race have actually facilitated automation in plowing and the use of autosteer systems ( 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 cultivating. Several tractor companies have also been working on producing a driverless tractor.


Engineering

The durability and engine power of tractors made them very suitable for engineering tasks. Tractors can be fitted with engineering tools such as
dozer blade A bulldozer or dozer (also called a crawler) is a large, motorized machine equipped with a metal blade to the front for pushing material: soil, sand, snow, rubble, or rock during construction work. It travels most commonly on continuous tracks, ...
s, buckets,
hoe Hoe or HOE may refer to: * Hoe (food), a Korean dish of raw fish * Hoe (letter), a Georgian letter * Hoe (tool), a hand tool used in gardening and farming ** Hoe-farming, a term for primitive forms of agriculture * Backhoe, a piece of excavati ...
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 A bulldozer or dozer (also called a crawler) is a large, motorized machine equipped with a metal blade to the front for pushing material: soil, sand, snow, rubble, or rock during construction work. It travels most commonly on continuous track ...
is a 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 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 The pallet fork is a component of the lever escapement of a mechanical watch. The pallet fork and the lever form one component that sits between the escape wheel and the balance wheel. Its purpose is to lock the escape wheel, and release it one t ...
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 loaders, but nicknamed "
Bobcat The bobcat (''Lynx rufus''), also known as the red lynx, is a medium-sized cat native to North America. It ranges from southern Canada through most of the contiguous United States to Oaxaca in Mexico. It is listed as Least Concern on the IUC ...
" after the original manufacturer, are particularly suited for small excavation projects in confined areas.


Backhoe

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 A backhoe—also called rear actor or back actor—is a type of excavating equipment, or digger, consisting of a digging bucket on the end of a two-part articulated arm. It is typically mounted on the back of a tractor or front loader, the latt ...
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 Hoe or HOE may refer to: * Hoe (food), a Korean dish of raw fish * Hoe (letter), a Georgian letter * Hoe (tool), a hand tool used in gardening and farming ** Hoe-farming, a term for primitive forms of agriculture * Backhoe, a piece of excavati ...
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 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 urban engineering projects, such as construction and repairs in areas too small for larger equipment. Their versatility and compact size make them one of the most popular urban construction vehicles. In the UK and Ireland, the word "
JCB JCB may refer to: * JCB (company), a British manufacturer of heavy industrial and agricultural vehicles * JCB Co., Ltd., originally Japan Credit Bureau, a credit card company based in Tokyo, Japan * JCB Prize, a literary award sponsored by the c ...
" is used colloquially 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

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 with available
power take-off A power take-off or power takeoff (PTO) is one of several methods for taking power from a power source, such as a running engine, and transmitting it to an application such as an attached implement or separate machine. Most commonly, it is a sp ...
(PTO) power ranging from . CUTs are often equipped with both a mid-mounted and a standard rear PTO, especially those below . The mid-mount PTO shaft typically rotates at/near 2000 rpm and is typically used to power mid-mount finish mowers, front-mounted snow blowers 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. One of the most common attachment 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 structures just like agricultural tractors. The most well-known brands in North America include Kubota, John Deere Tractor, New Holland Ag, Case-Farmall and Massey Ferguson. Although less common, compact backhoes are often attached to compact utility tractors. Compact utility tractors require special, smaller implements than full-sized agricultural tractors. Very common implements include the
box blade A box blade is a type of implement used on tractors for smoothing and contouring land. It is almost always unpowered, though can have auxiliary hydraulics attached in order for adjustments to be made without leaving the seat of the tractor. It ...
, the grader blade, the landscape rake, the post hole digger (or post hole
auger Auger may refer to: Engineering * Wood auger, a drill for making holes in wood (or in the ground) ** Auger bit, a drill bit * Auger conveyor, a device for moving material by means of a rotating helical flighting * Auger (platform), the world's f ...
), the rotary cutter (slasher or a brush hog), a mid- or rear-mount finish mower, a
broadcast seeder A broadcast seeder, alternately called a broadcaster, broadcast spreader or centrifugal fertilizer spreader (Europe) or "spinner" (UK), is a farm implement commonly used for spreading seed where no row planting is required (mostly for lawns and me ...
, a
subsoiler A subsoiler or flat lifter is a tractor-mounted farm implement used for deep tillage, loosening and breaking up soil at depths below the levels worked by moldboard ploughs, disc harrows, or rototillers. Most such tools will break up and turn over ...
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.


Standard

The earliest tractors were called "standard" tractors, and were intended almost solely for plowing and harrowing before planting, which were difficult tasks for humans and 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

A general-purpose or row-crop tractor is tailored specifically to the growing of crops grown in rows, and most especially to cultivating these crops. These tractors are universal machines, capable of both primary tillage and cultivation of a crop. 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 Deere & Company, doing business as John Deere (), is an American corporation that manufactures agricultural machinery, heavy equipment, forestry machinery, diesel engines, drivetrains (axles, transmissions, gearboxes) used in heavy equipment, ...
designed the 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. Oliver refined its "Row Crop" model early in 1930. Until 1935, the 18–27 was Oliver– Hart-Parr's only row-crop tractor. 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 A rollover protection structure or rollover protection system (ROPS) ( or ) is a system or structure intended to protect equipment operators and motorists from injuries caused by vehicle overturns or rollovers. Like rollcages and rollbars in ca ...
(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
rollover Rollover or roll over may refer to: Arts and entertainment * ''Rollover'' (film), a 1981 American political thriller *''Roll Over'', a 1992 album by Hound Dog * "Roll Over", a 2006 song by Zico Chain * "Roll Over", a 1989 song by Steven Wayne ...
. Canadian agricultural equipment manufacturer Versatile makes row-crop tractors that are ; powered by an 8.9 liter Cummins Diesel engine. Case IH and New Holland of CNH Industrial both produce high horsepower front-wheel-assist row crop tractors with available rear tracks. Case IH also has a four-wheel drive track system called Rowtrac.
John Deere Deere & Company, doing business as John Deere (), is an American corporation that manufactures agricultural machinery, heavy equipment, forestry machinery, diesel engines, drivetrains (axles, transmissions, gearboxes) used in heavy equipment, ...
has an extensive line of available row crop tractors ranging from . Modern row crop tractors have rollover protection systems in the form of a reinforced cab or a roll bar.


Garden

Garden tractors, sometimes called lawn tractors, are small, light tractors designed for use in domestic gardens, 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 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-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 hydraulic drives). Garden tractors from
Wheel Horse Wheel Horse was a manufacturer of outdoor and garden power equipment, including lawn and garden tractors. The company's headquarters were in South Bend, Indiana, USA. History The business was started in the two-car garage of Elmer Pond in 19 ...
,
Cub Cadet Cub Cadet is an American company that produces outdoor power equipment and services, including utility vehicles, handheld and chore products as well as snow throwers. History IH Cub Cadet was a premium line of small tractors, established in 196 ...
, Economy (Power King), John Deere, Massey Ferguson and Case 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

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 tractors 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 China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...
, Bangladesh, India, and other Southeast Asia countries. Most two-wheel tractors today are specialty tractors made for one purpose, such as snow blowers, push tillers, and self propelled push mowers.


Orchard

Tractors tailored to use in fruit orchards 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 cowlings and fairings that allow branches to deflect and slide off rather than catch); spark arrestors on the exhaust tips; and often wire cages to protect the operator from snags.


Automobile conversions and other homemade

The ingenuity of farm mechanics, coupled in some cases with OEM or 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 In the history of the 20th century, the interwar period lasted from 11 November 1918 to 1 September 1939 (20 years, 9 months, 21 days), the end of the World War I, First World War to the beginning of the World War II, Second World War. The in ...
, dozens of manufacturers ( Montgomery Ward among them) marketed aftermarket kits for converting
Ford Model T The Ford Model T is an automobile that was produced by Ford Motor Company from October 1, 1908, to May 26, 1927. It is generally regarded as the first affordable automobile, which made car travel available to middle-class Americans. The relati ...
s for use as tractors. (These were sometimes called 'Hoover wagons' during the
Great Depression The Great Depression (19291939) was an economic shock that impacted most countries across the world. It was a period of economic depression that became evident after a major fall in stock prices in the United States. The economic contagio ...
, although this term was usually reserved for automobiles converted to horse-drawn buggy use when gasoline was unavailable or unaffordable. During the same period, another common name was " Doodlebug", after the popular kit by the same name.) Ford even considered producing an "official" optional kit. Many 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). During World War II, a shortage of tractors in
Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...
led to the development of the so-called "EPA" tractor (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 A vehicle frame, also historically known as its ''chassis'', is the main supporting structure of a motor vehicle to which all other components are attached, comparable to the skeleton of an organism. Until the 1930s, virtually every car had a ...
, 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 km/h and allowed people aged 16 and older to drive the cars with a moped license. The German occupation of Italy during World resulted in a severe shortage of mechanized farm equipment. The destruction of tractors was a sort of scorched-earth strategy used to reduce the independence of the conquered. The shortage of tractors in that area of Europe was the origin of
Lamborghini Automobili Lamborghini S.p.A. () is an Italian brand and manufacturer of luxury sports cars and SUVs based in Sant'Agata Bolognese. The company is owned by the Volkswagen Group through its subsidiary Audi. Ferruccio Lamborghini (1916–1993) ...
. 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''
rom ''arbetstraktor'' (work tractor) Rom, or ROM may refer to: Biomechanics and medicine * Risk of mortality, a medical classification to estimate the likelihood of death for a patient * Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac * R ...
the main difference is an A tractor has a top speed of 30 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. The
SFRO SFRO (Sveriges fordonsbyggares riksorganisation) is a Swedish national organisation founded in 1982 with the goal of making it possible to register amateur built vehicles. The goal of SFRO is to help builders to build their own vehicles and registe ...
is a Swedish organization advocating homebuilt and modified vehicles. Another type of homemade tractors are ones that are fabricated from scratch. The "
from scratch From scratch may refer to: Radio and television * ''From Scratch'' (radio), an American National Public Radio series about "the entrepreneurial life" * ''From Scratch'' (TV series), a 2022 Netflix original series * "From Scratch", a 2006 epis ...
" 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 A chassis (, ; plural ''chassis'' from French châssis ) is the load-bearing framework of an artificial object, which structurally supports the object in its construction and function. An example of a chassis is a vehicle frame, the underpart ...
is essentially designed and built by the owner (e.g., a frame is welded from bar stock—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 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 units or traction heads, familiar as the front end of an
articulated lorry A semi-trailer truck, also known as a semitruck, (or semi, eighteen-wheeler, big rig, tractor-trailer or, by synecdoche, a semitrailer) is the combination of a tractor unit and one or more semi-trailers to carry freight. A semi-trailer ...
/ semi-trailer truck. They are heavy-duty vehicles with large engines and several
axle An axle or axletree 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 the vehicle, with the wheels rotating around the axle. In the former case, bearing ...
s. ** The majority of these tractors are designed to pull long semi-trailers, 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 " artic cab" (short for "articulated" cab). ** A minority is the
ballast tractor A ballast tractor is a specially weighted tractor unit of a heavy hauler combination. It is designed to utilize a drawbar to pull or push heavy or exceptionally large trailer loads which are loaded in a hydraulic modular trailer. When feasible ...
, whose load is hauled from a drawbar. * Pushback tractors are used on airports to move aircraft on the ground, most commonly pushing aircraft away from their parking stands. *
Locomotive A locomotive or engine is a rail transport vehicle that provides the Power (physics), motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, Motor coach (rail), motor ...
tractors ( engines) or
rail car mover A railcar mover is a road–rail vehicle (capable of travelling on both roads and rail tracks) fitted with couplers for moving small numbers of railroad cars around in a rail siding or small yard. Vollert has developed an unmanned road-rail rem ...
s – the amalgamation of
machine A machine is a physical system using Power (physics), power to apply Force, forces and control Motion, movement to perform an action. The term is commonly applied to artificial devices, such as those employing engines or motors, but also to na ...
s, electrical generators, controls and devices that comprise the traction component of railway vehicles * Artillery tractors – vehicles used to tow artillery pieces of varying weights. * NASA and other space agencies use very large tractors to move large launch vehicles and Space Shuttles between their hangars and launch pads. * 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. File:UP Diesel.png, Diesel-electric
locomotive A locomotive or engine is a rail transport vehicle that provides the Power (physics), motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, Motor coach (rail), motor ...
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 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


Nebraska tests

Nebraska tractor tests are tests mandated by the Nebraska Tractor Test Law and administered by the University of Nebraska, that objectively test the performance of all brands of tractors, 40 horsepower or more, sold in Nebraska. In the 1910s and 1920s, an era of snake oil sales and advertising tactics, the Nebraska tests helped farmers throughout North America to see through marketing claims and make informed buying decisions. The tests continue today, making sure tractors fulfill the manufacturer's advertised claims.


Manufacturers

Some of the many tractor manufacturers and brands worldwide include: * Belarus * Case IH *
Caterpillar Caterpillars ( ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder Sym ...
* Claas *
Challenger Challenger, Challengers, or The Challengers may refer to: Entertainment Comics and manga * Challenger (character), comic book character * ''Challengers'' (manga), manga by Hinako Takanaga Film and TV * ''The Challengers'' (TV series), a 1979 ...
* Deutz-Fahr * Fendt * Iseki *
JCB JCB may refer to: * JCB (company), a British manufacturer of heavy industrial and agricultural vehicles * JCB Co., Ltd., originally Japan Credit Bureau, a credit card company based in Tokyo, Japan * JCB Prize, a literary award sponsored by the c ...
*
John Deere Deere & Company, doing business as John Deere (), is an American corporation that manufactures agricultural machinery, heavy equipment, forestry machinery, diesel engines, drivetrains (axles, transmissions, gearboxes) used in heavy equipment, ...
*
Lamborghini Automobili Lamborghini S.p.A. () is an Italian brand and manufacturer of luxury sports cars and SUVs based in Sant'Agata Bolognese. The company is owned by the Volkswagen Group through its subsidiary Audi. Ferruccio Lamborghini (1916–1993) ...
* Landini * Kubota *
Mahindra Mahindra may refer to: Business * Mahindra & Mahindra, an Indian multinational car manufacturing corporation **Mahindra Truck and Bus Division, an Indian commercial vehicle manufacturer owned by Mahindra & Mahindra * Mahindra Group *Kotak Mahindr ...
* Massey Ferguson *
McCormick McCormick may refer to: Business * McCormick & Company, an American food company specializing in spices and flavorings * McCormick & Schmick's, an American restaurant chain specializing in seafood * McCormick Harvesting Machine Company, a manufact ...
* Mercedes-Benz * New Holland *
SAME Same may refer to: *Sameness or identity Places * Same (Homer), an island mentioned by Homer in the ''Odyssey'' * Same (polis), an ancient city * Same, East Timor, the capital of the Manufahi district * Samé, Mali * Same, Tanzania * Same Distri ...
*
Steyr Steyr (; Central Bavarian: ''Steia'') is a statutory city, located in the Austrian federal state of Upper Austria. It is the administrative capital, though not part of Steyr-Land District. Steyr is Austria's 12th most populated town and the 3rd l ...
*
TAFE Technical and further education or simply TAFE (), is the common name in English-speaking countries in Oceania for vocational education, as a subset of tertiary education. TAFE institutions provide a wide range of predominantly vocational cours ...
*
Ursus Ursus is Latin for bear. It may also refer to: Animals * ''Ursus'' (mammal), a genus of bears People * Ursus of Aosta, 6th-century evangelist * Ursus of Auxerre, 6th-century bishop * Ursus of Solothurn, 3rd-century martyr * Ursus (''praefectus ...
* Valtra * Zetor In addition to commercial manufacturers, the Open Source Ecology group has developed several working prototypes of an open source hardware tractor called the LifeTrac as part of its
Global Village Construction Set Open Source Ecology (OSE) is a network of farmers, engineers, architects and supporters, whose main goal is the eventual manufacturing of the Global Village Construction Set (GVCS). As described by Open Source Ecology "the GVCS is an open techn ...
.


Gallery

File:Trator.JPG, A Ford tractor in Brazil File:Tractors.jpg, Modern tractors, an
Ursus Ursus is Latin for bear. It may also refer to: Animals * ''Ursus'' (mammal), a genus of bears People * Ursus of Aosta, 6th-century evangelist * Ursus of Auxerre, 6th-century bishop * Ursus of Solothurn, 3rd-century martyr * Ursus (''praefectus ...
11054 and Fendt 820 File:A John Deere 9320 at a construction site in the US.jpg, A
John Deere Deere & Company, doing business as John Deere (), is an American corporation that manufactures agricultural machinery, heavy equipment, forestry machinery, diesel engines, drivetrains (axles, transmissions, gearboxes) used in heavy equipment, ...
9320 at a construction site in the US File:Mahindra tractor model1.jpg, A scale model of a modern Ursus and Fendt tractor in Germany File:Balnain 1997a (1).jpg, Farm tractor in Balnain, Scotland File:Traktor na oranju.JPG, A tractor pulling a chisel plow in Slovenia


See also

* Agricultural machinery * Artillery tractor *
Ballast tractor A ballast tractor is a specially weighted tractor unit of a heavy hauler combination. It is designed to utilize a drawbar to pull or push heavy or exceptionally large trailer loads which are loaded in a hydraulic modular trailer. When feasible ...
* Big Bud 747, the world's largest farm tractor * Driverless tractor *
Heavy equipment Heavy equipment or heavy machinery refers to heavy-duty vehicles specially designed to execute construction tasks, most frequently involving earthwork operations or other large construction tasks. ''Heavy equipment'' usually comprises five e ...
*
Lester F. Larsen Tractor Museum The Lester F. Larsen Tractor Test and Power Museum is a museum dedicated to preserving and documenting the history of Nebraska's tractor test law, operated by the University of Nebraska–Lincoln (NU) in Lincoln, Nebraska, United States. The Nebra ...
* Non-road engine *
Power take-off A power take-off or power takeoff (PTO) is one of several methods for taking power from a power source, such as a running engine, and transmitting it to an application such as an attached implement or separate machine. Most commonly, it is a sp ...
* Railcar mover * Terminal tractor * Tractor pulling * Tractor unit * Two-wheel tractor * Unimog 70200


References

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External links


Tractor information


Purdue University Tractor Safety Article re: ROPS, PTO, etc
*
Nebraska Tractor Test LaboratoryHistorical Tractor Test Reports and Manufacturers' Literature
Reports on 400+ models 1903–2006
A History of Tractors
at the Canada Agriculture Museum


Tractor safety


EU Working Group on Agricultural Tractors – Work Safety
* EU Directives on tractor design

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National Agricultural Safety Database The National Ag Safety Database (NASD) was developed with funding from the United States National Institute for Occupational Safety and Health (NIOSH), the US Centers for Disease Control and Prevention, and the USDA Cooperative Extension Service (C ...
)
Tractor Safety
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National Safety Council The National Safety Council (NSC) is a 501(c)(3) nonprofit, public service organization promoting health and safety in the United States. Headquartered in Itasca, Illinois, NSC is a member organization, founded in 1913 and granted a congressi ...
)
Adaptive Tractor Overturn Prediction System





CDC – Agricultural Safety: Cost-effective Rollover Protective Structures – NIOSH Workplace Safety and Health Topic
{{Authority control Agricultural machinery Engineering vehicles Heavy equipment Vehicles introduced in 1901