Steam Engines: The Why and How

Add to this a pump and/or injector to replenish boiler water, a lubricating system to feed water-soluble oil into the steam, a safety valve to prevent boiler explosion, a whistle to signal to the crew, and running gear and steering mechanism and you have a basic steam engine. Many other refinements appeared such as insulation to limit heat loss from the boiler, two cylinders to furnish more even power, use of compound cylinders to utilize more of the pressure left in the exhaust steam, and automatic controls to increase safety and lessen the need for constant attention. Entry of steam into the cylinder can be limited to certain parts of the piston travel, thus conserving steam when full power is not needed but when full speed must be maintained. The reverse lever will start and run the engines in either direction so reverse gears are not necessary.

The initial reaction to a first experience with steam power is one of amazement at the quietness of the operation; the second is a surprise at the great amount of power produced by a single cylinder. It should be pointed out that steam pushes the piston, at full power, through the full length of each direction of every stroke, not for just a part of every fourth stroke as in a gas engine. At one hundred pounds boiler pressure, a steam engine with a ten inch cylinder will have a constant force of about four tons acting on the piston. This translates into more than eighty horsepower which can be increased as needed by increasing the boiler pressure. Little wonder that this excellent source of farm power had such a profound impact upon the agricultural industry!

Many, many engines were broken up in the scrap drives during World War II but many, luckily, were saved. They have been restored by very special group of engine enthusiasts who have given freely of their time, talents, and resources to enable us to participate in this impressive sample of bygone years. They deserve our heartiest appreciation for saving this interesting part of our agricultural past for us to see. Although the heyday of steam use on the farm was a relatively brief one, it looms very large in the memory of our older members. The impact felt by the advent of this first large, portable source of farm power changed the whole future of agriculture, permitting the use of power-operated machinery, larger farm acreages and less manual labor. The opening of the midwest to large-scale cereal grain production for world markets was the direct result of steam plowing and threshing, and steam train and steamboat transportation. Thus, increases in farm food production during the first quarter to the present century can be traced directly to the use of the steam engine. Probably no other single invention had a greater share in developing the American farm to its present number one position in world food production.