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MODEL RAILROAD TRACK AND ELECTRICAL INFORMATION

Note: The author is not an electrical engineer or electrician. While the information on this page is believed to be sound, he cannot determine your skill level nor the quality of your work, and so disclaims any liability for any damage or injury. You should always use safe wiring and working procedures to reduce the chances of injury or property damage. If you are not certain that you are doing something correctly and safely, seek the advice of a qualified expert.
 
  Track
What Gauge Is It?
Know the Code
Railroad Ties

Electrical
Digital Command Control (DCC)

Track Alignment and Other Information

General Model Railroad Information
Rolling Stock Information
 

Track is Important

Track is what transforms a model into a model railroad. Taking a little extra time to ensure that your track is laid correctly will let you enjoy the other aspects of the hobby, instead of spending all your time picking up cars off the floor and redoing your track. Poor quality track leads to derailments, short circuits, and frustration. Take particular care with track switches, so that your trains will follow one track or the other, not "half-and-half" causing a derailment. An N.M.R.A. gauge (see the links page) will allow you to check that your track is not too wide or too narrow for reliable operations.

On modular layouts, there are more opportunities for track trouble, due to the removeable "bridge" sections of track that connect the tracks from one module to the next, and the potential for damage when modules are carried from one location to another. Some clubs run their tracks all the way to the end of their modules to eliminate the short piece of connecting track, but doing this means that the alignment of the modules is even more critical. It also means that their modules cannot be easily connected with other modules that do use the bridge tracks.

See also the discussion of rail codes, gauges, and scales elsewhere on this page.

Three important ways of looking at model railroad track:

  As a guideway for trains
On railroads, and on model railroads, the track guides the trains, keeping them on course. This is accomplished by the use of a flanged wheel. the flange along the edge of the wheel touches the side of the rail, which resists its force, pushing the wheel back toward the center of the track. On the other side of the track, the same thing is happening, so each pair of wheels is forced to stay between the rails. If the rails are not placed correctly (too far apart or too close together) this balance can break down, causing a derailment.

  As a conduit for electricity
On a real railroad, there is electricity in the rails, but it is there in a small amount to detect trains, and activate signals based on whether a train is in the area or not. On model railroads, there is electricity in the rails, but it is there to provide power for propulsion. Without this power, the trains won't run.
On a model railroad equipped with DCC, the signals from the throttle to the locomotive are also carried by electrical signals transmitted through the rails.

  As a scenic feature
The appearance of model railroad rails can enhance realism or detract from it. Real rails are not shiny, except on the top, and part of the inside edge - wherever the wheels touch the rails. Model railroad rails can also be weathered to look like the real thing, using paint. Floquil's "Rail Brown" or "Grimy Black" are good colors for the sides of model rails. The top should be wiped clean to allow for electrical contact with the wheels of model trains.
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What Gauge Is It?

Some modelers use the terms "scale" and "gauge" interchangeably, although they are not the same thing. Scale is the ratio between the model and the real object on which it was based, while gauge is the distance between the rails.

Most railroads in the USA today use two rails, and are built to the "standard gauge" of four feet, eight-and-a-half inches between the rails. Most railroads in the rest of the world use a gauge of 1435 millimeters; for those of you who aren't good at converting between metric and US measurements, that is four feet, eight-and-a-half inches. There are some railroads (in the U.S. and elsewhere) that were built to other gauges, usually referred to as "narrow gauge" or "broad gauge" depending whether they are narrower or wider than standard gauge. There are usually historical, economic, or political reasons why a different gauge is (or was) used, but the problem is that cars and locomotives designed for one track gauge cannot be used on track of another gauge. Sometimes, this was the aim - to keep cars from leaving one territory and entering another. Sometimes, narrow-gauge railroads were built because they were cheaper to construct. Before there was a standard gauge, there were a variety of different gauges used, and the inventor of each felt that his should become the "standard." Different countries often had (or still have) different gauges. For a great listing of gauges used throughout the world, take a look at this web site.
For more information on gauges, take a look at this web site.

Some model railroaders build models of narrow-gauge trains, and need special track to run their trains. HOn3 (HO scale, narrow-gauge, 3 foot) is a relatively popular scale and can be found at better-stocked hobby shops, but if you model in a scale or gauge that is not as popular, you may have to search to find track that fits your equipment, or make your own track. Sometimes, by coincidence, one scale's standard gauge track can be used by another scale's narrow gauge; for example, in O scale, a 30-inch-gauge train can run on the same track that would be used in HO scale for a standard gauge train.

There are a few things which add confusion to the situation. One is the fact that Lionel had a line of equipment years ago which was called "standard gauge" and since many people are familiar with this, they may be confused if you tell them that your trains are "standard gauge in HO scale." Another is what is called G-scale or G-gauge; this is a large scale sometimes used in backyard railroads. When it was invented, the gauge (distance between the rails) was set, but different manufacturers made equipment to different scales to fit the same track. Some of them are replicas of standard gauge equipment, and others are replicas of equipment in various narrow gauges. Notice here that the track gauge of the model track is the same, but that the scales change. For this reason, it probably is correct to call this one "G-gauge" rather than "G-scale." If you want to use it and build accurate models, you will need to decide which scale to use.
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Know the Code

You may hear model railroad track referred to as "code 100" or "code 70" and wonder what this code is. This code does not require the use of code books or complicated decryption; it is a measure of the rail's height, in thousanths of an inch. The rails used by real railroads vary in size, depending on the amount of use that rail is expected to carry. The rails used on model railroads are available in different sizes to duplicate this variation, although we vary our rail size mainly so that it looks right (or more like the real thing.)

Although most trains will run on your track regardless of what height the rails are, some modelers find that having the "correct" size rail looks better. What code, or size, of rail you use depends on what scale you are modeling in, and what type of railroad line you are modeling. In HO scale, code 100 used by many modelers because it is easily available, but some don't like it because it is "too big" to look right. Code 100 rail is 100/1000 (or 1/10) of an inch high. In HO scale, code 100 rail would be accurate for 155-pound-per-yard main line rail, but this was about the heaviest rail ever used in the U.S. Most modern main line tracks use 130-pound to 132-pound rail, which translates to code 83 in HO scale. For branch lines, yards, and sidings, lighter rails were used, and can be replicated using code 70, code 55, or code 40 rails.

In smaller scales, rail of these sizes may be "too big" or suitable only for main line use, and smaller-sized rails may be available. In larger scales, larger-size rails (code 125 or bigger) may be more appropriate.
Some sizes are available in prefabricated switches and "flex-track." while other sizes come only as loose rails that have to be "hand-laid" using individual wooden ties and metal rails. This is not as tough as it sounds, although the size and complexity of the track work makes a difference. Beginners should stick to the larger size rails and straight track, then work their way up to curves, switches, crossings, etc. One handlaid track "guru" whom I know said that working with code 100 rails is "easy" while code 40 rails are so light that you only have to look at them wrong to make them twist. Remember that code 40 rails are less thank half the size (4/10 to be exact) of code 100 rails.
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Railroad Ties

Yes, I know a couple of guys who have ties with railroad logos on them, but in this case I am talking about the cross ties upon which the rails sit.

Most railroad ties are still made of wood, just as they have been for over 150 years. Very early railways used stone blocks, but this practice was abandoned within 20 to 30 years. The blocks were prone to shifting in the soil, and did not maintain the rails at a consistent distance apart (see gauge elsewhere on this page.)

Wooden ties (usually 8 feet in length) were not only more flexible, but they also had far more surface area to resist movement, and had both rails spiked to them, so they could maintain a constant gauge between the rails, allowing smoother movement of trains. They were also much easier to install, even with unskilled labor.

Concrete ties were developed in the last half of the 20th century, and are now used on most "high-speed" main lines, including Amtrak's Northeast Corridor in the US, the TGV lines in France, and the Japanese Shinkansen lines. The heavier weight of concrete ties helps them resist movement even better than wooden ties, and better quality concrete than was used in the 1960s keeps them from breaking down under the pounding they get from passing trains.

Other materials have been used for railroad ties, including steel and plastic, but these are largely restricted to experimental use, or use in special situations.

Model railroad ties are either wood (used in handlaid track) or plastic (used in prefabricated track.) Occasionally, you may see ties made of PC (printed circuit) board material, but these are typically used in handlaid track where the situation calls for them. Model trolley layouts often have rails soldered to brass ties - this works for them because the "other" side of the electrical circuit is provided by the overhead trolley wire, but this would not work for most model railroad layouts.
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Electrical

Although most of us are not electricians or electrical engineers, model railroads are operated by electricity, so we should all have a basic understanding of electricity. The power supply you use for your railroad must be adequate for the size of the layout and the number of trains and accessories you are using. If the power supply is too small, your trains will not get enough power to maintain speed, your throttles will overheat, and you may blow a fuse in your power supply.

I am not qualified to tell you what size power supply you will need; if you are unsure, you should consult with someone who is. There are also books available on the subject.

Power also needs get from the power supply to the track, and ultimately to the locomotives. If the wires used to transmit this power are too small, the wires can heat up, and the amount of power arriving at the far end of the layout may be greatly reduced, causing trains to slow down when further away from the power supply. Make sure that you connect each module and track section to the power supply via wires and plugs, as rail joiners can loosen and lead to "dead spots" and poor performance.

Track should be kept clean, so that locomotives can pick up the power through their wheels. Some modelers use abrasive "brightboys" to scrape the dirt off the rails, but this wears away some of the metal, and can cause scratches in the surface, creating increased surface area, and increased oxidation of the rail surface.
Other modelers use a small block of Masonite for the same purpose, which causes less damage to the rails.
Still others use chemical cleaners, such as denatured alcohol or electrical contact cleaners. These work well, but should be used with caution, as they can be flammable, poisonous, or otherwise dangerous if not used properly.

Locomotive and car wheels should also be cleaned to keep them from depositing dirt on the track, and to maintain good electrical pick up.

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Digital Command Control (DCC)

One of the most important developments in model railroading in the last 20 years is DCC, or Digital Command Control. This technology allows more realistic operation and simplified wiring. There are several different manufacturers offering dozens of different systems, but some degree of standardization and interchangeablity exists, largely due to the efforts of the NMRA.

Generally speaking, everything below the rails will be made by one manufacturer. There are exceptions.
For example, we use Digitrax command stations, boosters, radio receivers, throttles, and throttle plug-in plates, but use Magna Force power supplies from DCC Specialties to provide powers to the boosters. This choice was based on advice from someone outside the club - someone who had experience in electronics. Learn from the experience (and mistakes) of others! It is easier (and cheaper) than learning from your own mistakes!

Above the rails, the decoders in the locomotives may be by several different manufacturers. Nearly all decoders will work with nearly all systems.

One thing DCC can not do for you is compensate for faulty wiring, short circuits or dirty track. In fact, track should be kept as clean as possible, to ensure that the digital signal is transmitted to the locomotive receivers uninterrupted and without distortion.
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Other Information

When setting up a modular layout, the alignment of the main line tracks is the first thing that needs to be done. Trains on these tracks will be more numerous, and running at higher speeds than trains on sidings or yard tracks. Use a level to make sure the mainline is level from left to right, using the adjustment bolts on the front legs to reach this goal. After this has been accomplished, use the back legs of the module to adjust the front-to-back level of the module. Additional modules should be aligned to meet the ones that are already set up, and then adjusted to maintain a level main line. If, for some reason, you arrange all the modules into a loop, level them all, and then find that the last one is two inches higher than the first one, don't try to compensate for this by just dropping the high end of the module two inches. This will introduce a sharp vertical kink into the main line, causing problems with the operation of trains. By adjusting three or four modules, the height difference can be spread out over a greater distance, minimizing its impact. Of course, you could go back around and re-adjust every module on the layout, but that is time-consuming and unneccessary. Most trains will be able to deal with some up-and-down variations as long as they are not drastic shifts.
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