All about tractors
As indicated in earlier columns, farming is a complex issue, from seed to harvest to distribution of the product in the marketplace. Technology has allowed the farmer to grow more on less land and with less water than ever before. One of the key components of that technology is the development of the tractor. For those of us who live in Imperial County, the sight of a tractor in the field and on the road is common. The tractor of today is certainly a far cry from the first tractors.
By definition, a tractor is an engineered vehicle specifically designed to deliver at a high tractive effort (known as torque) at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction. Most commonly, the term is used to describe a farm vehicle that provides the power and traction to mechanize agriculture tasks, especially (and originally) tillage but nowadays a great variety of tasks. 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 mechanized.
The word tractor was taken from the Latin word trahere, which means to pull. The first recorded use of the word meaning, “an engine or vehicle for pulling wagons or ploughs,” occurred in 1896, from the earlier term traction engine.
Early models
The first powered farm implements in the early 19th century were portable engines — steam engines on wheels that could be used to drive mechanical farm machinery by way of a flexible belt. While there were earlier versions, the first truly portable engine was invented in 1839 by William Tuxford of Boston, Lincolnshire, England. Over the next several years, the traction engine evolved and by the first half of the 1860s, great experimentation occurred. However, by the end of the decade, the standard form of the traction engine had evolved and would change little over the next 60 years. It was widely adopted for agricultural use.
Dan Albone, with his 1902 prototype agricultural motor, built the first successful gasoline-powered tractor. and he did not use the term “tractor.”
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 Iowa. In 1903, the firm built 15 tractors. Their 14,000-pound #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.
Enter Ford
Henry Ford introduced a light-weight, mass-produced design that largely displaced the heavier designs.
While unpopular at first, these gasoline-powered machines began to catch on in the 1910s, when they became smaller and more affordable. Ford introduced the Fordson, a popular mass-produced tractor, in 1917. They were built in the United States, Ireland, England and Russia, and by 1923, Fordson had 77 percent 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. A Fordson is shown in the accompanying photo of the tractor staged at Farm Credit Service in Imperial. While the written history of Imperial County that I could find does not cite the year of the first tractor used in farming, I am advised that this type of tractor was used here in the early 1900s.
Upgrades
Harry Ferguson (finally a name we can identified with the industry today) applied for a British patent for his threepoint hitch in 1926. That allowed three-point attachment of an implement to the tractor, and it is the simplest and only statically determinate way of joining two bodies in engineering. 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 shaft that could be used to power three-point-hitch-mounted implements, such as sickle-bar mowers. This PTO location set the standard for future tractor developments.
The classic farm tractor is a simple open vehicle with two very large driving wheels on an axle below and slightly behind a single seat. The seat and steering wheel consequently are in the center. The engine is in front of the driver, with two steerable wheels below the engine compartment. This basic design has remained unchanged for a number of years, but enclosed cabs are fitted on almost all modern models for reasons of operator safety and comfort.
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 and ethanol as common alternatives. 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.
Diesel power
Diesel fuel gained momentum starting in the 1960s, and modern farm tractors usually employ diesel engines, which range in power output from 18 to 575 horsepower.
Modern tractors have a roll-over protection structure to prevent an operator from being crushed if the tractor turns over. The ROPS does not prevent tractor overturns; rather, it prevents the operator from being crushed during an overturn. For the ROPS to work as designed, the operator must stay within its protective frame. This means the operator must wear the seat belt; not wearing it may defeat the primary purpose of the ROPS.
Those trips to the moon have been incorporated into agriculture in the form of global position system devices, and robust on-board computers installed as optional features on farm tractors. These technologies are used in modern, precision farming techniques. GPS is used in Imperial Valley to level the field for gravity irrigation. Several tractor companies have also been working on producing a driverless tractor, which is a sign of the times with the cost of labor and the lack of skilled drivers.
Tractors have evolved, but the farmers who use them to grow our food likely had a toy tractor as a child — ‘cause we all like really big toys. Just watch children at the fair go straight for the tractor display.