SOME GENERAL TRACTOR INFO FOR NON TRACTOR DRIVERS

SOME GENERAL TRACTOR INFO FOR NON TRACTOR DRIVERS

Since this blog concerns tractors to a great extent, I thought I might discuss some of the more esoteric terminology and the general classes of tractor types and how they came to be developed for those who might not know already.
Maybe a good place to start is with the origins of the word tractor itself. In the late 1800’s, several companies began selling steam powered “traction engines” for use in plowing the virgin prairies of the mid west, which were notoriously had to turn under for the first time. These were essentially scaled down locomotive boilers with steam engines driving large steel wheels through open gear trains, typically with 1 or maybe 2 speeds forward and one in reverse, and they moved about at walking speed at full tilt. They were also used to drive stationery threshing machines and the earliest stationery hay balers via large endless flat belts. They did the job and were much better than using teams which had to rest several times a day and ate all winter when they weren’t working. But these machines used vast amounts of coal or other fuel (sometimes straw) and lots of water, both of which could be hard to come by in some areas. They were also very labor intensive and not cheap to buy. They also had a tendency to crash through bridges due to there immense weight and if that happened, it often led to an explosion when relatively cold water hit the top of the boiler and cracked it. These were usually fatal to the operators. Meanwhile, inventors had been working on a different type of engine, which burned fuel directly in it’s cylinders and could be made simpler, lighter, and cheaper than steam engines. In 1892, an Iowan by the name of John Froelich used one of these internal combustion engines in a traction engine which he built using parts from a steam traction engine. It was the first traction engine to propel itself both forward and backward using a gasoline engine, and would eventually become the progenitor of the John Deere tractor line. Most of the early “gas traction engines” followed this trend and were quite large and heavy themselves. A company called Hart Parr (after it’s 2 founders Mr. Hart and Mr. Parr) were among the more successful of the early builders and in 1903, the company coined the term “tractor” in their advertising rather than the more cumbersome term “gasoline Traction Engine”. The name stuck and thus we have tractors today. By the way the Hart Parr company’s descendants are in business today. You may have heard of their brand name-Oliver. Oliver was bought out by the White Corporation and is today (many mergers later) known as AGCO.
It was thought for years that a tractor’s job was to do heavy tillage and threshing, not more precise work like planting and cultivating. In the beginning, this would have been quite true, because tractors, like steam traction engines before them, used a front axle with a central pivot point and a chain and winch system of steering, which to say the least was not very responsive. But during the teens, all the major tractor builders, hoping to increase sales, began trying to develop smaller, lighter tractors with handier steering that could be used to cultivate row crops like corn, a job that was done several times a year in those days before herbicides and insecticides. These were known as “Motor cultivators” Most of these attempts were unsuccessful, but the International Harvester Corp. adapted their motor cultivator designs and in 1924 came out with the “Farmall Regular”. The problem with motor cultivators was that farmers didn’t want to have the expense of having to buy another separate tractor unit just for cultivating- they wanted a machine that would do all the work on the farm. Motor cultivators typically lacked the weight, ruggedness, and horsepower to do this. But the Farmall and all the similar tractors that followed it solve this problem. These tractors came to be known as Row-Crop tractors, because they were particularly well adapted to the growing of crops such as corn, cotton, beans and so on that are planted in rows. Up till the very late 1950s they typically had front wheels that were mounted together on a “pedestal” beneath the tractor’s radiator, so that the front wheels could be driven between 2 rows, while the back wheels straddled those same rows. The rear wheels were typically much taller than those on other types of tractors in order to provide crop clearance later into the growing season. Most were equipped with a belt pulley on the right side if the tractor for driving threshing machines, balers, corn shellers, and other machinery. Another reason for the narrow front wheels was that no axle would interfere with the belt as it ran machinery. During the 50’s, cultivation began to give way to the much more convenient and cheaper use of herbicides and insecticides, and those narrow front wheels made tractors much more apt to turn over when crossing ditches, cornering too fast, etc., so they gradually gave way to wide front axles. Adaptability was and still is a hallmark of row-crop tractors, so they typically had side frames punched to accept several different types of bolt on equipment, and rear wheels that could be set to wider or narrower positions according to need (as can today’s wide front axles).In the late 20’s, another form of power transmission device began to take over from the belt pulley, though it took many years to do so completely. This was the PTO or Power Take Off- a splined shaft which typically comes out of the tractor above it’s drawbar in the rear, although you could get a mid point pto on some tractors and still can. At first these shafts turned at 540 rpm, but as tractor power climbed, 1000 rpm ptos became available and still are today. Another innovation that became common on row-crop tractors is the power lift for lifting cultivator gangs, plows etc. at first these were mechanical, but were replaced by the more versatile hydraulic lift systems that are now in common use.
As all this development was going on with the row-crops, tractors were being optimized for those farmers growing cereal grains, too. These tractors came to be known as wheatland or standard tread models. To begin with, they adopted automotive type steering just as the row-crops had. Since these tractors didn’t need much crop clearance and were often used in hilly areas such as Washington’s Palouse region, they typically used shorter rear wheels for a lower center of gravity, and their axles do not allow the wheel track to be changed, hence the “standard tread” moniker. They also didn’t need to run anything other than threshing machines at first, so they often didn’t have pto’s. Later, when belt driven threshing machines were traded for combined harvesters (Combines for short), the combine was often driven by it’s own engine. Still later, self propelled combines relegated the tractors to the shed during harvest, though today, many grain growers use large grain carts which require a pto to empty. This keeps semi trucks from getting stuck in fields. Hydraulics were also deleted from these tractors many times, though with grain carts, you also need hydraulics to control the position of the unloading auger.
Another type of tractor that became common is the utility tractor. It combines aspects of both the row-crop and wheatland tractors. Though these tractors are typically low and have wide front axles, they also usually have adjustable front axle widths and at least some adjustability of the rear wheel width. They also have pto’s and hydraulic systems, most often including 3 point hitches, which were the greatest innovation of the most famous and maybe earliest of the type, the Ford Ferguson- also known as the 9N. They tend to have shorter wheelbases than standard tread tractors, often achieved by using a front axle that arcs of slants back toward the rear axle. This allows for shorter turning radiuses. There are scads of these tractors on the market today, billed as compacts or compact utility tractors, typically with four wheel drive, diesel engines, and front end loaders. Most sold today use infinitely variable hydrostatic transmissions, and have power steering, turn signals and 4 way flashers, just like cars. Some even have cabs. At first, many of these tractors found work as roadside mowing units, tugs used to move products in factorys, aircraft tugs, and in orchards and vineyards. Later specialized orchard and vineyard tractors were developed, mainly from this class of utility tractors.
The other major class of tractors you might hear about is the high crop tractor, which grew out of the row crop genre to serve a very small market- growers of tall bushy crops or those grown on raised beds. The most common use of high crop tractors is probably sugar can growing, which is done in hot, wet climates that tend to lead to rust, so if you find a used high crop tractor, it will probably be a real rust bucket. (In my opinion they are just plain ugly, too!)
So there you have it- a not so brief primer on tractor history and classification. Most tractor companies offered (or still offer) some or all of their models in several of these classes as variants of the base model. By far, the most common is the row crop, the least common is the high crop. Utilities are probably second most common, and standard treads are in third. A couple of other terms you might hear or read are distillate or tractor fuel. These were one and the same for all intents and purposes, and it was a fuel that would fall somewhere between kerosene and gasoline today. It was used because it was cheaper and less volatile than gasoline and was theoretically more powerful per gallon than gasoline. Using this fuel required that you get the tractor started on gasoline and get it warmed up to about 200 degrees coolant temperature, then when you shut the tractor down, you ran it out of fuel so that the carburetor would be ready for gasoline again when you were ready to restart it. Also, distillate would tend to preignite, so most tractors that used it were equipped with a water injection system that took radiator water and misted it into the carburetor along with the fuel. This led to many a cracked block when the weather unexpectedly took a turn toward the cold at night or when memory failed the owner and he forgot to drain the radiator. Antifreeze was a no-no in these tractors. In the 50’s distillate began to lose popularity in favor of gasoline and then diesel engines.
The final term you may not get the meaning of is “styled” or “unstyled”. This referred to the tractor’s sheet metal. In the beginning, sheet metal was used only where necessary for safety or to keep dirt out of things, and tended to be very simple in design and shape. In the 30’s, streamlining came into vogue in the auto industry and in aircraft, and took hold in most industries, tractor building among them. Oliver was probably the first to style their sheet metal in 1935. Allis Chalmers, John Deere, and Farmall all went to styled metal in 1939. It probably shows my age, but I still love the looks of the oliver 60 and 70, the WC from Allis Chalmers, the Farmall H and M, and the John Deere A’s,B’s and other letter series tractors.