Why do Farm Tractors have funny wheels and go slow

In the early 1700’s, the homes in Europe and America were heated with wood or coal. After centuries of habitation, the supply of wood near the bigger cities was used up so coal became the preferred source of heat. Although coal was abundant, the easy-to-get surface coal was quickly depleted requiring underground mining. With underground mining came the problem of extracting water from the mines, and that brought about the invention of the first industrial Steam Engine.

Thomas Newcomen was a blacksmith and inventor born in Dartmoth, Devon, England. He is often referred to as a father of the Industrial Revolution, primarily for his development of the Newcomen steam engine. Newcomen developed his steam engine with his business partner Thomas Savery in 1712. It was first used later that year at the Conygree Coalworks near Dudley in the West Midlands (England). Although its first use was in a coal-mining area, Newcomen's engine would find its greatest use pumping water out of the mineral mines such as the tin mines of Cornwall.

One hundred and twelve years after Newcomen, in 1824, a French Engineer by the name of Sadi Carnot (pronounced Car-know) published his study of the steam engine in a book entitled Réflexions sur la puissance motrice du feu (Reflections on the Motive Power of Fire"). Carnot’s scientific study of the steam engine produced the definition of an engine and his work later became the foundation for the Second Law of Thermodynamics.

Carnot’s definition of an ‘engine’ is one that produces work from a temperature difference, or work from the heat flow from a hot temperature to a cold temperature. For us today, that means taking horsepower from the difference between the combustion chamber temperature to the radiator temperature. All engines have a radiator in some form, which serves as a heat sink or the cold(er) side of the engine.

Under Carnot’s definition, we can identify the ‘external’ combustion (steam engine) and ‘internal’ combustion (gas or diesel engine). Under the heading ‘internal combustion’ we can identify the two cycle (outboard engine, chain saw) and the four cycle (most car and tractor engines). There are two main variations of the ‘external combustion’ engine including the piston engine (Rankine cycle) and the steam turbine.

In 1898, Rudolf Diesel was granted patent #608,845 for an “internal combustion engine.” Within the Diesel cycle, there are two engine types including the two-cycle engines (the Detroit Diesel or the model airplane engine) and four-cycle engines (most diesel tractors today).

An engine is a device that takes power from a temperature difference. A Motor is a device that takes power from non-thermal sources such as electricity (the electric motor), wind (the windmill), water falls (the water turbine), air tools in your shop and other potential energy sources. It seems strange that General Motors manufacturers neither motors nor engines as their primary product.

Newcomen’s machine was a stationary engine and could not be moved easily. As steam engines evolved to a better weight to horsepower ratio, it was possible to make the engine movable either by wheels, by boat or on rails.

There were several early attempts to propel boats by steam. Newcomen's engine was far from being suited to marine propulsion. The weight for a given power was enormous. Any engine of that era that was capable of developing power enough to propel a boat would have sunk the boat by its own weight.

The pumping engine of Newcomen had a simple up and down motion. Between 1775 and 1782, James Watt developed the Cornish pumping engine, and later the double-acting rotative (crankshaft) engine suitable for all kinds of power purposes. For the first time, the horse-power obtainable from an engine and its boiler was reduced within the limits of displacement of a boat that the engine could propel at a reasonable speed.

The locomotive, another version of a portable steam engine is usually credited to George Stephenson. None of today’s shop equipment was available and every part of the engine had to be made by hand. After ten months' labor, Stephenson’s first locomotive, called the “Blucher”, was completed at Killingworth (England) in 1814, and tested. On an ascending grade of one foot in four hundred and fifty feet, this engine succeeded in pulling eight loaded coal wagons weighing thirty tons, at about four miles an hour. This was the most successful working engine that had been constructed up to this time. Seeing all the defects of his first engine, and the effects of the steam-blast in facilitating the combustion of the fuel used in generating steam, George Stephenson set about constructing his second engine, with a patent date of February 28, 1815.

The fire engine is representative of the need to have an engine on wheels. Ctesibius of Alexandria (Egypt) is credited with inventing the first manually operated fire pump around the second century B.C. The first fire engine in which steam powered the pump was used was built by Braithwaite in 1829. John Ericsson is credited with building the first American steam-powered fire engine.

The first self-propelled steam engine was used as a fire truck and was built in New York in 1841. It was the target of sabotage by fire fighters and its use was discontinued. Motorized fire engines did not become commonplace until the early 20^th Century.

The first engine-powered farm tractors used steam and were introduced in 1868. These engines were built as small road locomotives and were operated by one man. The Charter Gasoline Engine Company of Sterling, Illinois, was the first to successfully using gasoline as fuel. Charter's creation of a gasoline fueled engine in 1887 soon led to early gasoline ‘traction engines’ before Hart-Parr coined the term “tractor”. Charter adapted its engine to a Rumley steam-traction-engine chassis, and in 1889 produced six of the machines to become one of the first working gasoline traction engines."

John Froelich mounted a Van Duzen gasoline engine on a Robinson chassis and rigged his own gearing for propulsion. Froelich used the machine successfully to power a threshing machine by belt during the harvest season of 1892 in South Dakota. The Froelich tractor is the forerunner of the Waterloo Boy tractor and is considered by many to be the first successful gasoline tractor known. Froelich's machine fathered a long line of gasoline engines including the Waterloo Boy. The Company was later sold to John Deere and became the two-cylinder tractor that some of us still love today.

Charles W. Hart and Charles H. Parr began their pioneering work on gas engines in the late 1800s while studying mechanical engineering at the University of Wisconsin at Madison. In 1887 the two men formed the Hart-Parr Gasoline Engine Company of Madison. In 1900, they moved their operation to Hart's hometown of Charles City, Iowa, where they found financing to make gas traction engines based on their ideas. The firm's first tractor, Hart-Parr No.1, was made in 1901. Hart-Parr joined Oliver in 1929, which previously made only plows starting in the middle of the 19^th century. .

J.I. Case produced a gas traction engine with a patent date of 1894. This early Case gas engine did not run well enough to be commercially produced. The Case Company produced over 36,000 steam engines, many with over 100 horsepower.

Between 1810 and 1830, Robert McCormick and his son Cyrus experimented with mechanizing a working version of a mechanical reaper. This reaper would serve as the impetus for the McCormick Harvesting Machine Company that was formed in 1848 in Chicago. Cyrus H. McCormick led the effort to bring together the largest harvester manufacturers of the day to form International Harvester in 1902. McCormick and International Harvester pioneered the first dealer distribution channel, the first full-line product offering implements, tractors, harvesting, hay, and other equipment. International Harvester’s signature product, the famous Farmall tractor, was the pioneer for row-crop tractors. It is interesting that the 1940s line of Farmalls, the C, H, and M were the initials of Cyrus H. McCormick.

Henry Ford produced his first experimental gasoline powered tractor in 1907, under the direction of chief engineer Joseph Galamb. It was referred to as an "automobile plow" and the name ‘tractor’ was not used. After 1910, gasoline powered tractors were used extensively in farming.  Fordson was one of the first mass produced tractors starting in 1916.  Plowing speed was 2.8 mph and it weighed over a ton.  It ran on kerosene and could plow 8 acres on one tank of fuel.

Early tractors utilized wide metal tires, especially in the rear of the machine to disperse the weight.   Front wheels often had ridges to help them steer in the dirt.  In 1932 Allis-Chalmers began to use pneumatic tires from Firestone Tire and Rubber Company.  The tires had a much better grip on the soil. Rubber tires have many advantages over the metal tires, including their weight.   Today most of the tires used are wide and grooved (cleated) for best results.

Problems with traction pushed engineers to design another form of wheels.  The caterpillar track was invented by a British company named Hornsby in 1905. A continuous belt with slats was fitted to the front and back wheels (tracks).  The patent for the track was sold to Holt (1919) and became the Caterpillar Company. Caterpillar tracts are still used in heavy earth moving equipment today.

Farm tractors replaced most horses in the 1920’s through the 1940’s. Gasoline tractors became red, green, orange and a variety of other colors. Tractors of the last 50 years have rubber tires with a wide cleated tread for better traction. They go slow, trading speed for the ability to pull heavy loads. They may look funny but the design of the modern tractor has lead to the greatest food production the world has ever seen.

Antique Tractor clubs are formed because there are still people that want to hear an engine come to life after 40 years of neglect in an old barn somewhere, and enjoy hearing the governor open-up while pulling a trailer load of corn up Mill Hill.

Ray Sensney

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