The Power of Steam – Part 3, by A.Y.


Heating the Water

While water management is one of the most important aspects of boiler operation, the other is being able to heat the water. Since the age of the steam engine, wood, coal, and oil have been the three main fuels used to boil the water. Each has their advantages and disadvantages, and this must be considered thoroughly for use at a retreat. In this discussion, oil will not be considered as a fuel; the reason for this is, like gasoline, it can be expensive to constantly replenish, needs large volumes of storage space, and takes refineries to process.

The first fuel that is commonly considered for use is wood. Most traction engines and small stationary boilers use wood, and their fireboxes are designed to most efficiently channel the heat. A wood burning firebox will be narrow and tall, allowing wood to be piled up inside to create a large burning mass. The bottom of the firebox will have grates for the wood to sit on, and these usually will be fixed and only can be removed when the boiler is cold for cleaning. A wood-burning steam engine will be the most useful for retreat purposes, as wood is the most common resource available to the average person. While the engines can have a large appetite for wood, they can also expedite the process of cutting, splitting, and moving wood to and from storage and can offset the extra needed supply. Just like with a woodstove, different types of wood will perform differently in a boiler. Pine and other softwood will burn very quick with high heat, but the fireman will have to constantly add more fuel to the fire. Hardwood will burn slightly cooler, but the wood will last longer and give heat over a longer period of time. Most often, boilers will be fueled with scraps of wood left over from other activities, since they are not picky about the size and type of wood used. Again, for our purposes, a wood-fired boiler would be the best option.

Coal is the other common source of fuel for boilers. While only some larger types of traction engines and stationary boilers are built to be fired with coal, most railroad locomotives built after the 1880s were designed to be fired with coal. A coal firebox will not be very deep, but rather will be wider and longer than wood fireboxes in order to give a large heating area. A coal fire works best when kept even and around three to four inches in depth. Piling coal too deep can cause cold spots in the firebed and lead to wasted fuel and less efficiency; keeping the firebed too shallow will cause holes in the fire and lead to uneven stresses on the metal and less efficiency as well. Likewise, if the coal has contaminants in it, such as mud or iron, clinkers can form where the impurities stick together. These clinkers can create a massive clump of waste. These have to be fished out of the firebox to prevent the fire from losing efficiency, as they block air from being pulled up through the fire, and they take up space where burning fuel needs to be. Coal fireboxes will have moveable grates that the burning coal sits on; these grates must be shaken from time to time to let the burned ash fall through them to keep the fire clean. While coal is currently very available, for our purposes it is not the first fuel of choice, as it must be transported to the retreat and can take up a large area for storage. However, it does not need to be refined as oil does, and it will store indefinitely without losing its ability to provide heat.

Regardless of whether the steam engine used will be fueled with wood, coal, or something else that can burn, the most important item is giving constant and careful attention to the way the boiler is operated. The water must be constantly added or taken away to maintain a safe level, and good firing by an experienced person is a must to obtain the best performance from the boiler. Once again, practical experience is the best teacher when it comes to firing a steam engine.

Lubricating the Boiler

Since the importance of water and fuel has been addressed, the next important step in operating a boiler is maintaining a good level of lubrication. Like any vehicle, vintage steam engines need constant oiling and greasing in order to keep operating. However, this is usually done by hand instead of a splash-oil method, and each moving part of an engine needs a different type of lubrication. The specific type of oil needed is called steam oil, as it is used to lubricate the cylinders, valves, and crossheads on an engine where steam will be applied. It is a heavy oil that is designed to be mixed with steam and can be injected into higher heat areas without being excessively thinned. It should be kept in a marked can and applied liberally to all higher temperature moving points. Too much oil is much less expensive and easier to replace than worn out and overheated metal. In common solid bearings, such as on old railcar axles or traction engine axles, regular used motor oil will suffice, if it is clean with no trash in it.

Greaseis also an important lubricant and can be used for crank shaft bearings and rod bearings. Soft grease is the easiest type to work with and can be applied with any common grease gun, but a hard grease called Alemite can be used when bearings will not be accessible for a long period of time, such as on a moving locomotive. Alemite grease comes in sticks and must be injected into bearings with a special grease gun and will release its lubricating properties continuously over an extended period of time. If an alemite stick drops on the ground, do not use it in the bearing, as it has picked up trash from whatever it was just dropped on, and it needs to be discarded. Just one grain of sand in the stick can ruin a perfectly good bearing. As with lubricating oil, liberally applied grease is better than not enough, and a large amount should be stored for use.

Like any vehicle with moving parts, these engines must constantly be inspected for wear and tear. Previously, problems such as scale and corrosion have been mentioned in this article, and these should be looked for on a constant basis. Frequent visual inspections are extremely important, and defects must be scoured for over all parts of the machine. Problems to look for include bulges, cracks, leaks, and wear on the firebox sheets and boiler barrel, which is the main part of the boiler. This includes pitting, grooving, corrosion, signs of overheating, mud, and trash in the boiler; it also includes any broken, cracked, and eroded staybolts, rivets, and fittings. Staybolts secure the firebox to the boiler and are fitted within a few inches of each other. They have a small hole in the center, which is used for inspection. No steam or water should be leaking or fizzing out of the hole, and nothing should be placed in the hole to plug it. If the staybolt is leaking, it means it is broken and should be replaced at the first opportunity. Bulging around the firebox is usually attributed to several broken staybolts in the same area and is very dangerous. If bulging is seen, the fire should be dumped immediately and the cause ascertained. Cracks in the boiler usually form first around corners and fittings, such as firebox corners, firedoors, washout plugs, and holes for appliances. Cracks are usually visible under steam, but inspection for them cannot be accomplished inside a hot firebox. Again, special care should be used when visually inspecting for trouble, and a person with a good eye and experience can spot them before they become a major problem. Most cracks can be repaired and welded up, but this should only be done by a person who has experience welding on boilers, as there are specific procedures that involve drilling holes in the steel to stop the crack before welding.

As technology advanced, better tools like hydrostatic tests and ultrasounding allowed better care of steam engines and boilers. Ultrasound machines are used to determine the thickness of the metal sheets of the boiler and firebox, and they are a must in the modern world for boiler inspections. This allows thin spots to be found and cut out and patched before problems develop or it fails catastrophically. Steam shows and railroad museums are excellent places to ask about ultrasound machines and who can perform them locally. This is a very specialized task and probably will not be as available during a societal breakdown, but if done regularly beforehand they can give you an idea about what is happening to the metal of the boiler.

Hydrostatic tests are another important boiler tool and are used to test boilers for soundness and strength before being pressured with steam. Water is forced into the boiler when it is cool and is pumped up to a pressure greater than the operating steam pressure. Different size boilers will have different pressures, and studies should be done to ascertain what pressure is appropriate for testing your particular boiler. The goal of hydrostatic tests is to determine if there are any weak spots, leaks, or cracks in the boiler before steam is built. If a part of the boiler does fail during the test, water will just come pouring out of the failure instead of having a boiler explosion. If a problem is found, the water can be drained immediately and repairs started, instead of wasting fuel and waiting for the boiler to cool down. This test is also done by a boiler specialist and must be done regularly while society is still well. Also, both tests will need to be done for inspection purposes and paperwork will need to be kept on the condition of the boiler, along with repair lists. Most states have their own boiler inspectors that come and declare if the boiler is safe or not. Also, the Federal Railroad Administration has agents that conduct their own tests on locomotives that are even more stringent than regular “hobby” boiler inspections.

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