Model Railroad Planning

model train

Ryan C Kunkle / The Spruce

Planning a model railroad can be a hobby unto itself. Many people never get beyond the design stage, afraid of not getting it right. Here lies the first secret to layout design; planning doesn't stop when construction begins. Don't be afraid to let your plans evolve as your layout progresses. But if you're still looking for ways to "get it right" from the beginning, here are some of the things to consider when designing your model railroad.

Planning for any model railroad involves five steps:

  1. Essentials: Defining the constraints and basic goals that will shape all other decisions.
  2. Givens and druthers: Within your basic constraints, what are your priorities?
  3. Standards: You've established some standards in step one, now its time to get specific about how the layout will be built.
  4. Best practices: Keep these tried-and-true conventions in mind when working on your design.
  5. Drafting the plan: With all of your goals and standards defined, its time to put it on paper.

The Essentials

What are the five essential elements in any model railroad plan? These factors will guide all of your other decisions.

Theme: What are you modeling? This includes the prototype, locale, and era. It also includes the operations you'll be replicating. You have a lot of freedom of choice here, but that doesn't make this decision any less essential. There is, after all, no reason to build a model railroad if it's not the railroad you want. A model railroad doesn't have to follow a specific prototype. Many modelers freelance, picking and choosing what they like best. Some even create their own railroad names, rosters, paint schemes, etc. It's your railroad, model what you like.

Area: How much space do you have? This is one factor that is more or less "fixed" from the start. But don't let the fact that you only have a small bookshelf convince you that you can't have a model railroad. With a little creativity, you can make the most of just about any space. Multi-level designs, modular layouts and other creative alternatives allow you to squeeze a lot into any odd-sized or shaped space.

Standards: Every model railroad has a list of constraints: minimum radius, maximum grade, etc. There is no simple answer to what is an acceptable standard, however. The theme of your layout will have a lot to say about what sort of standards need to be applied.

Take a minimum radius for example. An 18-inch radius curve is the standard train set curve in HO. Most trains will run on it but longer cars may derail, so its probably not best for a modern heavy mainline. It will work fine however for an HO scale industrial or narrow-gauge theme. In N scale, 18 inches is a very comfortable curve for just about everything. For larger scales, 18 inches is going to limit you to very toy-like trains or a nice O scale trolley layout, or a larger scale switching layout without deep curves.

Time and budget: Like space, we all live within certain time and budget constraints. Be realistic about what you can afford to build and maintain. Many modelers have homes filled with unassembled kits without a layout to call home. Starting small, planning for expansion, or building in modules or sections can get you running sooner and get you past those beginner's fears.

Scale and gauge: While some modelers do build railroads in multiple scales or build multiple layouts in different scales, for most of us one is enough. The size of the trains you choose will go a long way toward determining many of the subsequent standards you'll want to follow in your plan.

Combining gauges on a single layout is another matter altogether. Standard and narrow gauge trains all share a common scale, so your scenery won't have to compromise. Modeling an interchange between different gauge lines can add a lot of operation and visual interest. Since narrow gauge trains can normally negotiate tighter curves than their standard gauge cousins, they may be a way to get into a larger scale without needing a larger space.

Achieving your vision requires balancing your priorities and standards within the essential parameters of your layout. No two model railroads are ever the same.
Ryan C. Kunkle / The Spruce


Now that you've laid out the essentials, what do you really want? Take that basic theme you've already created and build upon it.

Making a list: Start with a list of all the things you want on your layout. Separate columns for "Must Have/Would Like/I'll Take It if I Can Get It" help keep things in perspective.

Your list should include things like scenic features, operating schemes, control systems, benchwork designs, and any other special desires. "Must be child-friendly," "Lots of bridges," "Plenty of switching," are all worthy goals.

Maybe you already have a favorite prototype. If so, take a look at your list and see what part of that railroad best suits your needs. A popular line like the Santa Fe, for example, could be used for a prototype for anything from a busy mountain mainline, to a seaside port switcher, to a flatlands racetrack.​

Maybe you don't know exactly what railroad you want to model, but you know what you want your layout to look like, or how you want it to operate. Your list can help point you in the right direction.

It's also a good idea to include smaller goals in these early plans as well. "All curves should be super-elevated," might not have a major impact on your final track plan. But keeping this goal in mind from the beginning will help ensure it gets done in the end.

Checking it twice: It's good to get everything on the list to start. But once your list is complete, be prepared to start cutting it back. You probably won't have room for everything. Let the negotiations begin.

This may take some time. With so many options available, there may be multiple ways to get what you want. You may not be able to change the essential elements of your layout plan, but you can be very creative in how you work within your constraints. You will probably revisit your priority list frequently as you proceed with the design.

Raccoon Creek Bridge
Ryan C Kunkle / The Spruce

Applying Your Standards

Now that you know what you want and how much space, money and time you have to build it, it's time to start making some hard choices and compromise and pull it all together.

Some compromises are harder to make than others. If you want a long mainline but don't have a lot of space, you'll need to consider a smaller scale or perhaps a multiple level layout. Model trains can climb relatively steep grades and negotiate tight curves and switches, but they have their limits. Clearances in yards, tunnels, bridges, etc. can only be so close. These minimums will be determined by the model trains you've chosen.

Other standards are more a matter of preference than necessity. Even the largest HO scale trains will negotiate a 24-inch radius curve. These trains would look much better on a larger radius, however. You may decide that you want to maintain at least a 30-inch or 48-inch minimum radius. If you do, it will greatly impact the track design you create.

Ultimately these higher standards give you more opportunity to compromise. Perhaps you can live with a 46-inch curve in just this one corner, or hide a tighter curve in a tunnel. Just make sure you can be happy with whatever compromises you choose and don't sacrifice quality for quantity.

K27 radius test
Ryan C Kunkle / The Spruce

Best Practices

No matter what scale you choose, what railroad you model, or how large your railroad may be, certain design tips will never steer you wrong.

Access: If you can’t reach it, you can’t maintain it. It is always a good idea to keep track within arm’s reach. This can have an impact on the size and shape or your layout. Access also includes tunnels and other long stretches of hidden track, and other important things like switch machines, electrical components, and operating accessories.​

If you do have the option of filling an entire room with trains, remember to leave enough room for you and your guests to move around as well. Aisle width is as important as platform width. Around-the-walls designs or moveable/removable benchwork sections can make layout access much easier and provide more interesting operating designs.

Keep it simple: The “spaghetti bowl” effect, or simply packing as much track onto a platform as possible often proves the adage, “Less is more.” Real trains rarely pass through the same scene repeatedly. A looping layout plan may add a longer run, but it detracts from the appearance that the train is actually going somewhere.

A balance between tracks and scenery can be hard to achieve, especially in yards where more track would seem to lead to more fun. It’s not the amount of track but how it’s used that matters. Especially on a small layout, a little space actually makes the railroad seem larger.

Height: There is no single best height to build your train layout, but it is still an important consideration in any design. Higher platforms offer more natural viewing angles for adults and easier access underneath for construction and maintenance. Lower platforms allow a longer reach for wider layouts and are more comfortable for children. Then there are multi-level layouts that combine the best (and worst) features of both.

Take a look at your list of needs and consider the layout height carefully before you begin construction. Ultimately, choose a height that is comfortable for you.

Expansion: You don’t have to build it all at once. If you are considering future expansion, plan ahead and make tomorrow’s project easier. Extending a track or two to the end of the current platform, for example, will allow you to add on without cutting into existing tracks.

Consider future needs when purchasing a power supply or control system as well. A starter power pack or basic DCC system may be fine for your current needs, but if you know you’ll need more power later it may make sense to spend a few extra dollars upfront. Not only will you be out the cost of the basic system later, but you may also find yourself replacing a lot of wiring under the platform.

spaghetti western railroad
Ryan C Kunkle / The Spruce

Drafting a Plan

Drafting a plan can be a lot of fun. There is a challenge in replicating a subject within constraints coupled with the artistic expression of creating a unique design. Indeed, many enjoy design so much they never build an actual layout. There are two ways to draft your plans for a model railroad; computer-aided design and good ol' pencil and paper. Both have their advantages, and both can yield excellent results.

Computer design: Many different design programs are available for model railroaders. These range from simple “click and drag” programs that use a library of standard tracks to sophisticated CAD software. Some create three-dimensional views or run virtual trains over the layout. While more elaborate programs offer greater flexibility for complex designs, they also present a steep learning curve.

Which, if any, program is right for you depends on the complexity of your plan and your comfort with computer software. If you really enjoy computer design, or if you are simply willing to put in the time to learn, a high-end program may be a worthwhile investment.

The ability to take a flat design and show it in three dimensions is an asset on layouts with grades and multiple track levels. The ability to design in layers allows you to see potential construction problems before they happen. Some programs are so sophisticated, modelers simply choose to build and operate entirely in the “virtual” world.

Layout design BC (before computers): There is nothing wrong with drawing a plan with your own hands. Just like a computer program, with practice, you can get very proficient at drawing track plans that not only look good but work well.

  • Start with a rough sketch. Some amazing layouts got their start on the back of a cocktail napkin or a school notebook.
  • Next, add some actual measurements to the plan. A ruler and compass are all you need. Graph paper can help maintain scale. Track planning templates with standard sizes track pieces are also useful and available in every major scale.
  • Your plan can be as simple as an outline of the platform and track or done in layers to include benchwork design and scenic features.
  • Once you’ve got the tracks down, consider adding a little color by drawing in scenic features with colored pencils or markers.

And of course, if you change your mind, an eraser or a blank sheet of paper is never far away. You’ll be surprised how quickly your eye can spot the curve that’s too tight or the yard tracks that are a little too close together even without measuring.

A "model" model railroad: If you’re still not satisfied, the ultimate plan is a 3-D model. These mockups don’t need to be complex. Some balsa or basswood, paper and perhaps a little modeling clay are all that is necessary.

Mockups are especially useful for multi-level designs. These models allow you to see how the levels will interact. Scale figures can also be used to help determine aisle widths and viewing angles.

track planning tools
Ryan C Kunkle / The Spruce