Model scale comparison

There is a plethora of different model building scales out there, and if you like scratchbuilding, you're not limited to those that have kits available. Here's a quick roundup of the most popular scales in model railroading and how they compare to other model building hobbies.

The basic scales

Scale	Ratio	Track gauge (inches)	Common curve radii (inches)	Notes
Z	1:220	0.257	5¾ 7 11/16 8 11/16	the smallest commonly available scale
N	1:160	0.353	9¾ 11 19	currently the second-most popular scale
	1:144			some toys (like the old Micro Machines) and airplane models are built to this scale; models can be used near the foreground of N scale layouts for forced perspective
TT	1:120	0.47		developed in Germany as a "table top" scale, now making a bit of a resurgence
HO	1:87.1	0.649	18 24	currently the most popular scale
OO	1:76.2	varies from 0.649 to 0.75		currently the most popular scale in the UK, most commonly using the same track gauge as HO scale
S	1:64	0.883		scale modeling often seen in the form of Sn3 narrow gauge railroads; 3/16 inch = 1 foot
O	1:48	1.25		used to be known as "the king of scales"; ¼ inch = 1 foot
	1:24			most common automobile modeling scale
G	varies from 1:20.3 to 1:32	1.772		commonly used in garden railway applications

 

The modifiers

So what do all those "n3", "n2½", "e" and "m" (and many more) appendages on scale names mean? Generally, it means that the models are to the scale shown but the trains run on tracks that are modeled at something other than standard gauge (which measures at 4 ft 8½ inches for prototype railroads). The "n" designates "narrow gauge" and the number after it indicates the prototype track gauge (in feet) being modeled. For example, HOn3 is HO scale with 3 foot narrow gauge track; the former Denver & Rio Grande Western operated on 3 foot track, so many DRGW narrow gauge modelers build HOn3 models.

The special cases are the "e" and "m" appendages. HOe modelers are building HO scale models that run on standard gauge N scale track; it works out close to HOn2½, or 2½ foot gauge track. The "m" is an abbreviation for metre gauge, so Nm is N scale operating on 1 metre gauge track (a little smaller than Nn3 track).

For further reading

There are quite a few more scales than I've listed, these are just the most common. For more information, see:

• NMRA Standard S-1.1: Standards for Proto Models
• NMRA Standard S-1.2: Standards for Scale Models
• NMRA Standard S-1.3: Standards for Scales with deep flanges
• Wikipedia: Rail transport modeling scales

Modelling the Undec & Western

Undec & Western??? Yes, the Undec & Western. It's another term for freelancing. But why would anyone want to build a model railroad that never existed? The best answer is that the modeler likes too many different models to restrict himself to a particular prototype or era. But how do you make all that stuff up? Well, let's find out......

Before we get too much further into this discussion, I need to point out that, yes, there are quite a few women who are active model railroaders. Personally, I know one who has earned an MMR certificate from the NMRA, and another who is quite close to earning hers. My own wife is a model railroader (why do you think I asked her to marry?). For most of this article I refer to the model railroader with masculine terms merely to keep the prose simple.

Favorite prototypes

Just like any other model railroader, the freelancer has favorite prototype railroads too. The only difference is that the freelancer doesn't always restrict himself (or herself) to a particular time and place in the real world. His world is more imaginary, but takes the "best" parts of his favorite prototype to use as standard practices on his own layout. For example, Tony Koester's former Allegheny Midland was based on the question "What if the Nickel Plate got to West Virginia?"

Favorite equipment

Rather than a single favorite prototype, the modeler may decide that he has several favorite pieces of equipment (be it motive power, freight cars, or whatever). The modeler can then unite all of these favorites together into a single railroad that may have never had any of the equipment except one piece. A prime example of this is John Allen's Gorre & Daphetid that was all steam powered except for a triceratops and a giant from another scale.

Favorite era and/or locale

Maybe the modeler just likes everything there is to do with a certain era. Again, the modeler can take his favorite parts and unite them all together into a single railroad. The New England Berkshire & Western is based on this idea; trains run on rights of way roughly based on the Rutland and the Central Vermont railroads of the 1940s and 50s.

Creating the name (building an identity)

There are several ways to choose a good name for the railroad. The easiest is for the modeler who works on the favorite prototype scheme. He can make his railroad the "Montana Division of the Southern Pacific Railroad" even though the SP never got to Montana on its own tracks; or he could model the Monon Railroad as it might appear in the mid 1980s even though the real road was merged into the Louisville & Nashville in 1971. The most common scheme however, is that the railroad is a completely new entity on the planet (it doesn't necessarily have to be in the US, or on Earth for that matter).

One idea that I actually started building, the Minnesota & Pacific, roughly follows the route of the Milwaukee Road from Minneapolis westward, although most of the equipment is second hand from the Santa Fe. I chose the name because at the time I was a big fan of Prairie Home Companion (from Minnesota) and lived in Los Angeles (on the Pacific).

The modeler could also choose something based more on the style of common railroad names, like the Burlington Central. In this case the name was taken from a local high school in Illinois, and the modeling scheme (what if the Burlington Northern and Illinois Central were to merge?) grew from the name.

The herald

A railroad's herald (or logo) is probably it's most important identifying mark. The herald can use just the railroad's initials (in my case M&P) or the entire railroad name. The most important thing here, especially when you're designing a railroad that is not based on a real prototype, is to be as absolutely creative as possible. I've included three somewhat standard herald ideas here plus one created by just sitting in front of my drawing program and playing around for a little while. Don't think that your herald can't ever change, though. Prototype heralds (and paint schemes for that matter) change quite often, so once you've chosen, you're not locked into it for life.

Favorite prototype modelers using their own railroad name can use their favorite prototype's herald as a starting point and just let the creativity flow from there.

Placing the railroad (era and locale)

Every railroad is built to move freight and/or passengers from one point to another, so every model railroad has to run between at least two places (not necessarily cities). Where & when the railroad runs is usually somewhat set by the identity and modeling scheme chosen for it. If the railroad is the St Louis & Houston RR, then the railroad should (but doesn't necessarily have to) run between the two cities in its name. The railroad could, though be a bit more ambiguous, like the Buckshot Southern. In that case the modeler is a little more free to choose the cities the line serves.

A railroad need not serve two cities, however. It could be a switching line that runs mainly on city streets in a single large city; it could be a privately owned and operated industrial line that gets rocks from the mine to the smelter; it could be a tourist line that runs just two trains per day out and back; or it could be a major passenger terminal operator in a large city.

Wherever the layout is placed, it should be placed in a certain time frame. This will mainly be set by the equipment that the modeler chooses to buy for the railroad. If he likes tiny 4-4-0s and 2-6-0s, he could make the railroad a narrow gauge line in the 1890s; if he buys C40-8s and SD60MACs, it should be set in the 1990s.

But how do I model it?

Once you've decided on an identity, era and locale for your railroad, you're ready to start building your empire. If the railroad is going to be an imaginary division of an existing railroad for your era, the choices of rolling stock (and structures) are somewhat obvious. The exception would be a scheme like the Illinois Central of the 1980s building track into the mountains toward the Carolinas (since that would entail more rugged terrain than the IC really goes over, they might want a few tunnel motors or SD45s).

The idea here is to choose equipment that matches the terrain and era more than anything else. A mountain narrow gauge line of the 1920s isn't going to have too many diesels, nor is a Class I mainline through Kansas in the 1970s going to have any 4-4-0s (well, okay, this might actually happen, but it will be the exception rather than the rule). A little common sense goes a long way when the locomotive foreman is making his purchases (regardless of what the treasurer thinks!).

As to paint and details, again, the favorite prototype modeler's choices are somewhat obvious, but any freelancer can buy any piece of rolling stock for his own road. The easiest and best, of course, would be undecorated models. Buying "Undec & Western" saves lots of time and aggravation since nothing needs to be taken off the model, and the model is more or less ready for the new home road's paint and decals.

If the necessary model is not available undecorated or you can get a large quantity of them (not necessarily all in the same paint scheme) at a great price, don't be afraid to remove the existing paint. It's a lot easier than you might think. There are too many paint stripping products out there to list them all here, so ask at your local hobby shop for recommendations.

If you're too afraid of removing paint that's already been applied, you could just add a patch of paint or colored decal sheet over the offending road's reporting marks and add your own. You could also use any of the myriad of weathering techniques to hide the old road's marks to add your own. Rolling stock is often painted in "black patch" style like this on the prototype, so why not do it on the model?

I've got a name, herald and equipment, now what?

If you're going to model your own road (especially if you've got a somewhat elaborate herald), you might want to consider getting custom decals made for your road. It may cost a bit more, but the way the equipment looks after applying your own custom decals can't be beat by picking and choosing from alphabet and number sets. Custom decal and dry transfer print shops advertise every month in the popular model railroad magazines. Write to them for their terms (minimum size of the run, colors, lettering styles, logo sheets, etc), get some samples and bids for your work (you are hiring them, after all), and choose the one you like best.

Tell me more about ....

Now that you've got all the models built and running you can turn your railroad executives toward other related projects. Passengers and employees that ride on your regular passenger trains need something that says they are allowed to be there, so design a pass for them. Your railroad might be large enough to issue stock certificates, so print them. Your railroad does move between two points, so make a map. Your railroad didn't just instantly spring to life in its current and extremely elaborate form, so write a corporate history. Your railroad has regular trains, so publish a timetable. Your railroad has some standard operating procedures, so publish a rulebook. Just let your creativity run wild.

Rule Number 1: This is My Railroad

Don't forget the first rule of model railroading. Make your empire the way you like it. As you add new features to your railroad it will take on an identity and personality all its own, and don't ever be afraid to change anything later.

Rule Number 2:

If there are ever any doubts as to the prototype accuracy or any attributes of any item used in or near the model railroad, refer to rule number 1.

Size does matter - selecting a modeling scale

You've decided what you want to model and you know the size of the layout location. There's one more decision yet to make, and it's one that will affect your model building purchases for quite some time. You need to decide on what scale to use in your model building.

Scale vs. Gauge

First of all, there is one important distinction to learn, and that's the difference between scale and gauge. In short, these two terms can be defined as follows:

Scale

The ratio of miniaturization of an object.

Gauge

The distance between the rails on a section of track.

It may be easier to think about the difference between these two terms by thinking about their effect on a model person populating your model railroad. The scale of the model railroad will affect how tall a person stands, while the gauge will have no effect on how tall a model person stands.

Most railroads operating today use standard gauge as the spacing between the rails on their tracks. Generally, this works out to a rail spacing of 4 ft, 8½ in (1435 mm). But, prototype railroads throughout history have used different gauges, especially in the early 19th century before standard gauge was widely adopted. No matter the gauge a railroad used, be it 2 ft, 3 ft, or even 6 ft (as was seen on some early Russian railroads), a 6 ft tall person will still stand 6 ft tall in your selected modeling scale.

Popular model scales

The NMRA specification for standard model scales is documented in S-1.2: General standard scales. While there are other scales that are used for modeling (such as G, 1:24, and 1:200), this document contains the most common scales that you are likely to find at your local hobby shop.

The most popular model railroad scale right now is HO scale; this generally works out to a 1:87.1 ratio of model to prototype sizes. A 6 ft tall person in HO scale would stand at 0.83 inches tall. N scale is currently the second most popular model scale, which is measured as a 1:160 ratio. The same 6 ft tall person stands 0.45 inches tall in N scale.

Along with the size of a person and potential modeler eyesight issues, another major determining factor in selecting a scale will be the minimum radius of a circle of track in each scale. In HO scale, 18 inches is used as a normal minimum radius, while in N scale, 9¾ inches is often used as a minimum radius. Larger scales, naturally, have a larger minimum radius (24 inches is common in O scale, for example). Trains will simply not operate well on radii tighter than the minimum radius in each scale, but wider radii will not only allow you to operate larger equipment on the same track, the equipment will also look quite a bit more realistic on broader curves.

Which scale for you?

There is no "best" answer in all cases. The most common answer is HO scale due to its popularity, but you are by no means restricted to this scale alone. To make the selection, you have to take into account several factors including:

• the size of the layout space available
• the amount of equipment available for your chosen prototype and era
• the amount of fine detail that you want to be able to see on your layout (do you want to see each individual rivet?)
• your desired scenery-to-track ratio
• layout portability
• your own physical accessibility

It's important to note here what is not included in these criteria. For one thing, I did not include layout operations in the equation. No matter what scale or gauge you choose, you can operate your layout with the vast majority of operating schemes that are common today; the model's size does not generally make a significant impact on its operating qualities or its appropriateness for use in operating sessions. What does matter is your own physical accessibility. If your eyesight does not allow you to read the reporting marks on smaller scale equipment, for example, then you may want to choose a larger scale. Other physical limitations such as height and mobility should be taken into account, but they are generally not significant factors in selecting a modeling scale.

After factoring in all of the selection criteria, this is ultimately a personal decision. Some modelers choose a scale that lets them purchase equipment and run it out of the box with little or no modification; others may purposely choose an obscure scale or one that does not have a wide variety of commercially available equipment as a challenge to themselves. Whatever scale you choose, just remember that changing scales is not entirely unheard of. Many modelers start modeling with smaller scales and increase their scale size as they age for various reasons, and there are others that decrease their scale sizes as they age too (I used to know one modeler who switched from HO to N scale after he got into his 80s).

If you're having a hard time deciding, purchase a couple kits and some equipment in the scales that you're considering and try them out. You'll find that as you work with the models, you'll naturally gravitate toward your own scale and gauge preference.