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O-Gauge Railroading Frequently Asked Questions

This page contains answers to frequently asked questions concerning O-gauge railroading. If you have any questions not answered here, please feel free to contact us.

NOTE: This page is under development and is incomplete in some areas.


1. I'm new to this hobby. Where do I start?
2. What is O-Gauge?
3. Is there a difference between O-Gauge and O-Scale?
4. I've seen terms like O-27, O-36, O-42 and O-72. What do these mean?
5. What companies make O-Gauge trains, track and accessories?
6. Who makes the best O-Gauge trains?
7. Where can I buy O-gauge trains?
8. What's the difference between TMCC, DCS and Conventional?

9. I'm looking to buy used trains. Any advice?
10. What are the systems used to identify the condition (grade) of new and used toy trains, and how do I use them?

Q: I'm new to this hobby. Where do I start?
A: The best place for a newcomer to the hobby to start is a local train store. The friendly staff at any local train will be happy to answer any and all questions you may have and will make recommendations on your first purchase. The Internet is a wonderful utility for buying trains, but if you're just starting off there really is no substitute for walking into a train store and talking to a real person. If you live in the Atlanta area, you can find a list of local train stores right here. Joining our Club is also a good step if you're new to the hobby because it's a great place to start networking with other enthusiasts.


Q: What is O-Gauge?
Put simply, O-Gauge refers to model trains that run on tracks with 1.25 inches between the outer rails. Some O-Gauge tracks have 2 rails and some have 3 rails, but in either case they are both considered O-Gauge because the distance between the 2 outer rails is 1.25 inches. For more information, check out the Wikipedia article on O-gauge.


Q: Is there a difference between O-Gauge, O-Scale and O-27?
A: Although these terms are often used interchangeably, there actually is a difference. O-Gauge simply refers to any model trains which ride on tracks where the outer rails are 1.25 inches apart. That said, there are 2 main divisions within the O-Gauge hobby. O-Scale refers to O-Gauge trains that are built to scale in order to closely match the real-life prototypes. American O-Scale trains are usually built to 1:48 scale, which means that 1 inch on O-Scale is the equivalent of 48 inches (4 feet) of the real-life counterpart. European O-Scale trains, which have been gaining popularity in America in recent years, are usually built to either 1:48, 1:45 or 1:43 scale. Because O-Scale trains are quite large, they require wider curves to function correctly and look realistic. What this means is that O-Scale trains, while more realistic looking, take up more space. What about O-gauge trains that are NOT built to scale? These fall into a separate category called O-27. O-27 trains are the "classic" O-Gauge trains that Lionel made famous back in the days after World War II and which are still very popular today. O-27 trains are usually slightly smaller than O-Scale trains and are easier to fit into a small space since they do not require the wide curves that the larger O-Scale trains do. When walking into an O-Gauge train store, you will probably notice that some O-Gauge trains are smaller than others. This can often be confusing, but now you know that you're actually seeing 2 different types of O-Gauge trains: O-Scale and O-27. It usually won't look right if you mix O-27 trains with O-Scale trains on the same layout, so think carefully about what you really want before you make your first purchase. Determining which direction you want to go in is strictly up to you. Some people enjoy the more toy-like look and feel of O-27 trains, while others strive for realism and go for O-Scale trains instead. Some people base their decision on the amount of space they have to work with. And of course, some people dabble in both O-27 and O-Gauge (though they will usually keep each on a separate layout from the other. Keep in mind that what you've just read are only suggestions. There are no "rules" and whichever direction to choose to go in, you're in store for years of enjoyment and excitement!


Q: I've seen terms like O-27, O-36, O-42 and O-72. What do these mean?
A: The numbers refer to the diameter of a circle of track. For example, a circle of O-72 track is 72 inches in diameter.
Generally speaking, larger O-Scale trains require larger curves in order to look realistic. Additionally, some O-Scale trains are physically unable to run on smaller curves. For this reason, most O-Gauge trains will have a "minimum curve requirement" stated in their description which informs the buyer of the minimum curve which the item can successfully traverse. Because O-Scale trains often require a larger curve to run correctly, they require a more space to operate in. Smaller O-27 trains, as their name implies, do not require the larger curves that O-Scale trains do and can therefore operate in a much smaller area that their larger O-Scale counterparts.


Q: What companies make O-Gauge trains, track and accessories?
A: Although there are many, many companies that make O-Gauge stuff, if you're just starting off in the hobby there are basically 5 brands you need to know about: Lionel, MTH, Atlas, Weaver, and Williams. Here's a chart that will let you know what you can expect from each of these major O-Gauge manufacturers:

O-Scale Trains
O-27 Trains
O-Gauge Track
O-Gauge Accessories
Atlas O
Atlas Master, Atlas Trainman, Atlas Industrial Rail
Lionel, American Flyer, K-line
MTH Electric Trains
MTH, RailKing
Weaver Models
Weaver Models
Williams by Bachman
Williams by Bachman


Q: Who makes the best O-Gauge trains?
A: Nobody. Deciding which manufacturer is "best" is a completely subjective process and is purely a matter or personal opinion and preference. Every manufacturer imparts unique characteristics to their trains that make them special. A better way to answer this question would be that there no companies that make bad O-Gauge trains. The important thing to remember is that all O-Gauge trains are compatible with each other, so don't feel that you have to limit yourself to just one brand.


Q: Where can I buy O-Gauge trains?
A: The best place to start buying O-Gauge trains is from a local train store. Most train stores have many items in stock that you may be interested in, any they can order anything else you may want. Aside from your local train store, there are many ways to find what you want. If you're looking for a specific MTH product, you can use the search tool on the MTH website to locate any dealers in the United States that have the desired item in stock. Atlas O sells many of their products through their online store. Weaver Models sells all of the product offering through their online store as well. Lionel has a limited online store, so it's usually best to consult your local Lionel dealer for any Lionel items you may be interested in. Another fantastic medium for purchasing (and selling) O-Gauge trains is If you're patient, you can usually find almost anything you're looking for on ebay, and occasionally you can get a real deal on something! Of course, you should always excercise caution when shopping on ebay. You shop at your own risk, so try to stick with sellers who have a high positive feedback rating. It's easy to get carried away when a bidding war ensues over some item, so use some common sense when you get into those situations. Above all, when shopping on ebay remember that if something looks too good to be true, it may very well be. In addition to online options and train stores, there's always the train show or swap meet. Train shows and swap meets can be a great place to get hard-to-find items, used items and all sorts of odds and ends.


Q: What's the difference between TMCC, DCS and Conventional control?
A: TMCC and DCS are digital systems use to control modern O-Gauge trains. These systems allow a wife arrange of control options for your trains and are both quite amazing. Conventional Control refers to the "traditional" non-digitally controlled trains. This includes any pre-war or post-war Lionel engine as well as any modern engines made with only conventional control. The following is a more detailed description of each of the afore mentioned control systems.

Conventional Control
Conventional control is nothing more than the "classic" way of controlling an electric train. Power is applied to the track and the train engine responds to the applied power by moving forward or backward. Changing the voltage applied to the track controls how fast the train moves and can also blow the horn. Under conventional control, you have no control over individual engines and unless you employ some very complicated wiring (blocks and relays) you cannot easily run more than 1 conventionally powered engine on the same track at the same time. All pre-war and post-war Lionel engines were controlled by conventional means and many engines made today are still powered in the same fashion. Because of their simplicity, conventionally controlled engines are very inexpensive and are often included with starter sets. If money is extremely tight, conventionally powered trains offer an low-cost way to enter into the hobby. If you can afford to spend a little extra money, however, it's probably better to start off with a set that has digital control available. Keep in mind that most digitally controlled O-Gauge trains can operate in conventional mode, so by purchasing a set with digital control you can start off using conventional control and later utilize the digital features if you so desire.
DCS (Digital Command System)

Digital Command System (DCS) is the proprietary digital control system created by MTH Electric Trains. This system works by transmitting an electric digital signal along with the power from the transformer to the track.  The unit operates all MTH equipment that is equipped with the Proto-Sound 2.0 system. DCS can also control Lionel TMCC controlled engines to some extent. DCS can also control conventional engines.

The DCS system transmits the digital signal through the center rail. All new MTH O-gauge engine are equipped with the DCS system. DCS is updateable.  By going to the MTH website you can download updates to the DCS system.  You can also add sound new sound systems to engines. For DCS to run TMCC equipment you have to own the TMCC base unit. With DCS you do not have to remember engine numbers. When a DCS looses it's signal it will continue to run at it's last command until it pick-ups another command. DCS give you the ability to read your signal strength anywhere on your layout.

TMCC (Train Master Command Control)
Train Master Command Control (TMCC) and their new updated version, Legacy, is manufactured by Lionel. This system also transmits digital signals and power into the track allowing the operator full control over their railroad. The Lionel system transmits the digital signal through the outside (ground) rails. All new Lionel O-gauge engines ARE NOT equipped with the digital system.  You need to check the engine for the digital system. Atlas, Weaver and 3rd rail use TMCC/Legacy equipment. TMCC does not have train speed readout. With TMCC you have to remember what number you assigned to each engine. When the TMCC looses it's track signal the engine stops or shutters. Legacy speed control has three times the granularity of DCS speed control which permits greater (longer running before requiring an adjustment) unattended operation. The TMCC remote does not have any kind of a read out display. Legacy has an LCD screen.


Q: I'm looking to buy used trains. Any advice?
A: This document may help.


Q: What are the systems used to identify the condition (grade) of new and used toy trains, and how do I use them?
A: Please read this document.
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