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Thursday, April 23, 2015

The Power of Steam – Part 1, by A.Y.




You have bullets, beans, band-aids, bibles, bullion, and everything else you can imagine for when the cataclysmic end of society as we know it arrives. You bug out to your retreat and have everything ready to weather the storm of looters, power hungry officials, and no infrastructure, but have you considered an alternative way to pump water? What about an alternative way to power electric generators? An alternative way to power machinery? An alternative way to move heavy equipment place to place? A way to help rebuild your community, using some clean water and anything that will burn? I am referring to the 200+ year old technology of the steam engine. In this article, I will discuss what comprises a steam engine, types of engines, what it takes to run and maintain them, benefits of operation, some dangers, and where to find them and information about them.
Using steam for power can be traced back a few thousand years, but it did not become practical until the 1700’s, when steam was harnessed to pump water out of mines and strapped to wheeled carriages to make the first locomotives. Since then, steam power grew exponentially. It is the reason for the Industrial Revolution, as it provided power where water wheels could not. To be technical, it is an external combustion design where the steam heated in a pressurized boiler must be piped somehow to the engine, which either by reciprocation with pistons or steam turbines energy is turned into useful work. These engines, though labor intensive, brought forth the modern era and rushed many blossoming countries to become industrial powerhouses. While the “golden age of steam” vanished in the 1950s, doing away with most railroad locomotives, tractors, and the like, steam has kept up with technology and is still a large part of infrastructure today. Super high-pressure boilers in nuclear power plants, coal and gas power plants, and industrial facilities turn out energy in fantastic amounts. For our purposes, the nineteenth and twentieth century older brothers are the best choices.
An older model steam engine comprises of two main parts, the first of which is the boiler. There are two main types of boilers: Firetube and watertube. A firetube boiler is a large hollow cylinder with a firebox at one end and a smokebox at the other, with flues or firetubes passing through the boiler to connect the two. The flues carry the extremely hot gases from the firebox through the boiler, into the smokebox, and finally out the smokestack. Surrounding the firebox and flues is water, which heats up from the gases and creates steam. Firetube boilers can handle moderate pressure and varying demands of steam. The other type is a watertube boiler, which has the fire underneath the flues and water flowing through the flues or watertubes, creating pressure. These boilers can handle high amounts of pressure, but they do not handle varying steam amounts on demand. Most of the engines you will run into will have a firetube boiler.
The choices of older engines most appropriate to our needs fall into the three categories of
  • stationary engines
  • traction engines and portables, and
  • railroad locomotives.
First, a stationary engine is exactly what it sounds like; it’s a boiler supported on a concrete pad that never moves, and steam is piped to the engine or turbines that are located elsewhere. These are the most stable type of boiler and engine, as they never move over ground or rails and therefore don’t have the added stresses of moving over uneven ground. The water inside is always level, making them somewhat easier to control. They are often used where large machinery is set up to provide power; an example could be an electrical generator. Some advantages of stationary steam engines are that boiler size can be increased. Since it doesn’t have to move, the boiler can be set up to power multiple machines, and permanent defenses and shielding can be constructed around them to protect them from marauders. However, they cannot move, and thus are useless to transport items or if work is needed to be done longer distances away.
Traction engines and portables fall into the most useful category, as these engines are able to move to where the work is located. Engines called portables are just boilers and engines with a flywheel PTO mounted on a wagon frame with wheels, allowing it to be towed to the work site. While these are useful, they are limited to the amount of work they can do because they can’t move themselves; they must always be pulled by another piece of machinery or draft animals. Traction engines, however, not only have the ability to power machinery with a flywheel and belts, but they can pull themselves and other things around via gearing to the wheels and having steering mechanisms. This type of engine is the best to have at a retreat or community, as it can perform work at one location, say a sawmill, then haul the cut lumber to the building site, then go pump water, or power generators or whatever else it needs to do. However, to be able to power itself for movement, size and therefore power is usually somewhat restricted.
Third on the list are railroad steam locomotives. They are what most people think of when they hear the term “steam engine”. They are boilers and engines mounted on steel frames with steel wheels running on steel tracks, with the pistons powering the wheels directly, weighing anywhere from a few tons to over one million pounds. There are a few models still in existence that have pistons that turn driveshafts to power the wheels (Shays, Climaxes, Heislers, and Willamettes), and these are the most valuable to a community with rail access. These smaller locomotives have the unique ability to negotiate poorly maintained or horribly laid track smoothly and climb steep grades, up to 10 percent. While several people would question the usefulness of such a locomotive, when society is rebuilding at a faster pace and communities want to trade bulk goods with each other, no better machine can be found, assuming there are railroad tracks that join the places wishing to do business. While the primary job of these locomotives is to move up and down the rails, they can also act as stationary steam engines with steam transfer pipes fitted or as air compressors, as they use air to stop their trains.
While these three main types of engines have their own advantages and weaknesses, if you look carefully at communities in the last two centuries you will find more often than not all three working together to accomplish work. A traction engine would haul logs down to a mill powered by a stationary engine, then the cut lumber loaded onto a train powered by a railroad locomotive. While it would be incredibly advantageous to have all three types, limited budgets and practicability must force a choice of one, or perhaps two. For example of price, I was privy to a recent traction engine sale. The engine and boiler had been recently restored and certified, and it went for $30,000. While that’s quite a large sum of money for most people, it is not completely unattainable. It could be a large group purchase, for example.
Before rushing out and purchasing your favorite choice of steam engine, it is extremely important to understand how it works, what is needed to make it work, some dangers of operation, where to find extra support and information, and to know that it is NOT a toy. This article is just a basic introduction, as it takes years of experience and knowledge to be proficient at operating and maintaining one of these engines. So, first we will take a look at the basic items a steam engine needs in order to run.
The first and most important thing a steam engine needs is water. A firetube boiler, as discussed before, is a large hollow cylinder with a firebox at one end and a smokebox at the other, with firetubes or flues running in between. The top of the firebox is roughly two thirds of the height of the boiler and is surrounded by water. The heat from the fire and gases pass from the firebox, through the flues, and out the stack, heating water as they move. The water ABSOLUTELY MUST stay above the top of the firebox, which is called the crown sheet. If it does, everything goes well and the engine operates like it should. If the water drops below the crown sheet and exposes the top of it to steam, the extreme heat from the fire will begin to melt the steel top of the crown sheet. When the steel finally gives way, all that hot water in the boiler (far hotter than boiling temperature) will instantly turn into steam when depressurized and blow the boiler up into the air and into little pieces, taking the crew with it. This is called a boiler explosion, and the most important thing to take away from this is once again: Do NOT EVER let the water drop below the top of the crown sheet.

From the Survival Blog

Parts 2, 3, and 4 to follow.

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