Drawing Your Layout - Manual and Software Solutions

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There are several ways to design and build a layout. The first is a brute force method of just starting to lay track and see where it takes you. If this is your preference (and I know of several large layouts which were designed and built like this), then go for it. However, this site and group are more devoted to those people who want to design the layout before starting to build it.

The second way is with pencil (not pen) and graph paper. John Armstrong developed a method of designing a layout using what is called "Armstrong Squares". More detail can be also be found in books published by Kalmbach (among others).

A third way is to use a computer program to design the layout. There are many out there which will do the job. You can always use a pencil to scetch ideas, then when you have something that seems good, you can transfer it to your computer design program of choice.

Why even draw a scale layout plan?

There are at least four good reasons to prepare a scale track plan and design drawing for your dream layout:

  1. A scale drawing is a great check method to confirm that everything will fit.
  2. The drawing is there to remind you of your earlier plans because your memory can play tricks on you.
  3. A picture/diagram will save about a thousand words when you try to describe your layout plans to colleagues.
  4. Diagrams and drawings are records for the changes you incorporate as you build. Maintenance, too, is easier with a current design that you may modify continually as your layout changes.

How do I begin my layout plan?

Do your homework first

See what other people have done. Visit other layouts, and talk to the people who built and operate them. Get some good input from as many sources as possible. Attend train shows and check out the layouts for ideas, and talk to the ones who built them. If a model railroad club in your area built the layout, spend time with them learning how they created it. Contact your local model railroad hobby shop, and discuss your ideas with them. Hobby magazines such as Model Railroader may also inspire you. Read great books on track planning like John Armstrong's Track Planning for Realistic Operation by Kalmbach Publishing. A good book on bench work is How to Build Model Railroad Bench Work, written by Linn H. Westcott and published by Kalmbach Publishing Company . Get acquainted with the N.M.R.A. ( National Model Railroad Association), and Layout Design Special Interest Group and its guidebooks on layout design.

What is your environment?

Where is your railroad located - Far West, Midwest, Rocky Mountains, or the East? What era, industries, equipment, and location do you intend to model? What kind of equipment do you want to run: steam, diesel, or some of each such as occurred during the 1950's and 1960's transition period? Do you want to focus on passenger or freight trains? What is a typical passenger and freight consist? What industries use those kinds of cars, and do you want to model those industries? What radius curves will be required for your long articulated steam engines or short narrow gauge locomotives or four- and six-axle diesels. Do you want a switching yard out in the open or hidden? There are lots of environmental considerations to consider before starting in on a track plan, and they all make a very big difference in how you design your track work.

Is your room finished?

Complete your room and lighting construction before you start building your layout. In this way, you will not have to crawl over or under your layout to install room lighting, ductwork, or paneling. If your floor is concrete, paint and seal it to keep dust and dirt away from your layout.

How much space is available?

Sometimes we have either small spare bedrooms, attic rooms with tough access or weird ceilings, poorly lighted and damp basements, or garages that are too hot in the summer and too cold in the winter. Whatever your available space, be sure to measure it carefully and note the locations of doors, windows, and other obstacles (drain pipes, furnaces and other utilities, electrical panels, doors and cabinets, overhead obstructions, etc.). Spend some time drawing the space to scale. Construct a 3-D model of the space if desired. Start a three-ring binder for your design and make Page 1 your layout space drawing.

Maximizing the size of your available space requires a great deal of the layout designer's creativity. John Armstrong describes these as "political boundaries." You may want to read about them before proceeding in order to maintain peace in your household.

Allow enough work-space for your own needs, too. The width of your aisles is very important if you intend to have operating sessions with several people. Finally, ensure that you have maximum accessibility to any layout spot. If you can't reach critical layout sections to work on them or repair whatever's mounted there, you should think about some new ways to make that spot more accessible.

Key dimensions to remember are (1) room size, (2) minimum curve radius, (3) minimum switch number (5 or greater is highly recommended), (4) minimum aisle widths that depends on your width as well as your colleagues (3 feet is recommended), and (5) your arm reach (typically 28-35").

Move or Stay?

If you think you are going to move your layout to another location someday, you may wish to consider a modular or domino style layout. If so, light-weight materials are important. A modular layout made up of sectional bench work will let you remove the legs so that you can carry each section easily through the door when it's time to leave. If modularity makes sense, the NMRA issues guidelines for compatibility between sections so they will be easy to set up in another location and wired them together. On the other hand, permanent layouts may require different materials, and construction techniques. Each type -- temporary or permanent -- should be thoroughly evaluated in light of your own needs.

What's the best layout height?

Easy access to the layout's bottom side is crucial not only during the building and wiring phases but also for maintenance and modifications. Layout height preferences will also impact a lot of design decisions relating to scenery vertical heights.

Decide if you want to watch your trains from above (helicopter view) or closer to eye level (rail fan view). Also decide if you will be operating from standing or seated positions. Refer to Section D-7 CONTROL SYSTEMS for more information concerning this important subject.

If children are going to use the layout or visit frequently, it should be at a height so they can see the action when standing on the floor.

The correct layout height, however, ultimately depends largely on who will see, operate, and maintain your layout. Each layout builder has his own height needs.

Design by Squares

John Armstrong also writes a lot about conceptualizing your space in terms of the number of squares it contains. The size of the square is a function of your scale and minimum radius. A fairly common example square size has 26" sides for 22" minimum radius and 2" track-to-track spacing for HO scale.

Creative Doodling

Once you've measured your room, and determined the dimensions of your "Armstrong Square," start carrying available space drawing copies with you so that you can doodle main line track arrangements as ideas hit you. Quadruled paper with the 1/4" spacings is very convenient to use.

Available-space diagrams can then be drawn using a scale so that each square has 1/2" sides. For some of the smaller spaces, four such drawings will fit a single sheet of 8-1/2 X 11" paper. For this phase of layout design, the complex drafting tools consist of a pencil, credit card (for a straight-edge), and nickel (for circles). You'll find that eventually several of your "creative doodles" look good enough to be developed into a track plan. It will then be time to create a scale drawing.

Design Methods

Use either manual drafting methods or computer-aided design methods. The initial drawing time will be about the same with either method. Computer software can save time by allowing the drawing of frequently reused transition curves and switches where they must be individually drawn repeatedly with manual drafting tools. Use whichever method is more comfortable and understandable for you. Transition curves and switch drawing templates can be fashioned from styrene once you've picked a scale. John Armstrong uses a lot of templates for his manual drawings. See the K.I.S.S. Method described below.

Manual Drawing

Tools required include: A solid drawing table where you can leave your taped down track plans until you finish them is a must.

  • Excellent surface lighting
  • Good erasable drafting paper
  • T square & 30- and 45-degree right triangles
  • Engineer and architect scales
  • Scale conversion rulers (K.I.S.S. Method)
  • Calculator
  • K.I.S.S Method templates (see ...)
  • Eraser and eraser shield
  • Drafting or masking tape
  • Hard lead pencils and pencil point

Drafting Techniques

Draw with a light pencil line using a #3 or #4 pencil because you're going to be doing a lot of erasing. Draw your most complex track arrangement - such as a classification yard - first and then fit the rest of the track plan around it. The yard is most likely located paralleling a long wall.

Some modelers prefer track parallel to the walls and aisles, but often track at a slight angle to the walls and aisles will make the scenery look better.

Layered Planning

Diagram your room on one piece of paper. On top of that, use tracing or translucent paper to detail your bench work. Above that, use another layer to draw the lowest track level. Continue adding layers of track configurations as you work your way to the highest level of your layout. Dashed lines show when one line goes under something and are lost to sight. Colors differentiate levels or areas. Be as clear as possible when you make your track diagrams. Separate drawing sheets enable you to easily change one layer without disturbing another.


Mark all three ends of each turnout and remember to allow one to two scale inches for the lead before the points. Mark all your turnout numbers so that you know what number turnouts to use at each location when you actually start constructing your layout. Mark all the curve radii in the same way as well as for your anticipated elevations. Allow enough vertical clearance for your sub-road bed, roadbed, track height, and your tallest rolling stock and locomotives.


An easement is a transition, or spiral curve between a tangent(straight track) and a curve. The Easement starts out as a straight line of track that gradually becomes a tighter and tighter curve leading into a designated curved track. It reduces an abrupt outward swing of rolling stock and engines caused by centrifugal force when entering a relatively sharp curve. The use of easements can easily prevent derailments and improve operational appearance into and out of curves. Their use is suggested on curves with a radius less than 30" in HO, 15" in N scale, and 60" in O scale. Easements are not needed with the curved leg of a turnout since the turnout itself serves as the easement.

K.I.S.S. Method Track Planning Tools

a. If your preference is for the manual drawing method, these tools should help you create a layout design faster and better. Steve Moore developed this tool kit based on his own frustration with the general lack of such for designing layouts as well as personal encouragement from John Armstrong. b. These tools are a complete set of clear plastic tools for designing a model railroad on paper. c. The well-made kit includes the following: (1) Nineteen see-through multi-radius circles and holes for drawing track curves in O, HO, and N scale (2) Easement guides, tangent alignment tools, and scaled rulers

Software Design Tools

Here is a good article on what makes a good layout design program in the RRSoftware Yahoo group: Software Criteria . A brief summary of some of them follows:

Various Paint programs (ie: MS Paint): These programs are simple graphical drawing programs. Their advantage is that they are usually cheap or free. However, they are cumbersome to use and provide no assistance in various tasks which you need to do while designing a layout

XtrkCad: A free, powerful software package. This used to be a commercial package, but the author ended development and released it to the public. It is now under development by several dedicated individuals. It is also the only package available on Linux as well as Windows. It is said that a Macintosh version will soon be available. It is available at XtrkCad

RTS Freeware: Free software available from Atlas. The only track libraries are Atlas track. RTS Freeware

RRTrack: A good commercial package. Available at RRTrack

CADRail: A powerful commercial software package. CadRail

3rd PlanIt: One of the best packages out there. A new version has been under development for over a year. Right now there is no scheduled release date. You can get it at 3rdPlanIt. There is also a resource site which contains hundreds of plans and plan elements at 3pi.info

Templot: Not really a full track planning package, this is meant to design switches, for those people who lay their own track. However, the author has published instructions on how to use it with 3rd PlanIt.

TrainPlayer/TrackLayer: While not specifically a layout design program for building a layout, this allows you to lay out a plan and run the trains. It is extremely easy to use. Its best use is to test the operation of a plan drawn in another program. Since it was not intended to be a CAD program, there are no checks for bad switch design, tracks too close, etc. Available at TrainPlayer

MS Train Simulator: A simulator of full size trains, people have used it to design layouts. Train Simulator

Trainz: A simulator for model railroad layouts. TrainZ

There are likely other packages, feel free to add a description if you know of any.

Using a computer program to plan your layout

Planning a new train layout has consumed many of your hobby hours and the result is usually a stack of sketches and doodles that don't easily translate into a real working layout. Most of us spend 90% of our time dreaming up new track configurations but spend little time on anticipating our power and accessory wiring needs, placement of buildings and operating accessories, and the myriad little details necessary in a life-like railroad. It would be nice if all these layout elements could be designed at one time, on one infinitely variable media, then stored for later reference or changes.

Numerous books and how-to guides exist to help both novices and those who are ready to tackle their ultimate layout. While published layouts are all very useful to get ideas, they are fixed. This means that you can't take these track configurations and push and pull them like clay, and come up with your own variations.

Track planning computer software does allow you to mold and shape basic layout schemes on an electronic media, the computer screen. The computer drawing table is a virtual sketch-pad or drawing table on which the software enables our layout to take shape more quickly and accurately.

Software products like 3rd Plan It and RR-Track save time, increase accuracy, and enable you to more easily explore layout variations.

For example, if you intend to build an O- or HO-gauge layout, select a software package that accommodates both O- & HO-gauge track. Modern software planning packages usually allow for multiple gauges including G and N.

If you want both fixed or variable radius curves -- where you bend the curves to suit your design -- the software should enable you to mix and match the track most suitable to your needs. The software you select should allow you to specify custom-radius curves, and give you tools with which to create satisfactory tangents and easements.

The objective is to reduce the trial and error involved with custom cutting and fitting track after it is physically laid down on your bench-work.

Start simple by either planning several small practice layouts or a small portion of your intended layout in order to gain some experience with the software. The learning curve for computer-aided layout planning software is not great, but you do have to learn the commands that tell the software what you want done.

Most such track planning software is quite powerful, yet easy to use. However, you want to avoid getting lost and making time consuming errors until you become proficient.

In about 3-6 hours, you can lay out a working track plan depending on your skills with computer software. While this may seem like a long time compared to simply sketching the layout, the finished drawings are precise in terms of track requirements and scale. Further, you can save your design and change it as often as you like until you have a final track configuration.

Adding computer-generated track layers enables you to design a multi-level layout much easier. Stack the layers so that you can see where there is interference between tracks or insufficient horizontal or vertical clearances for the trains.

You can easily add track grades in order to create a highway overpass or mountain grade. You simply select a track section and tell how high to "lift" the section. The actual grade is specified in percent.

Depending on the software, you may be able to select a scale-size, colored diagram of each accessory or structure you want to position on your layout. This feature is extremely helpful in locating the item in the right place not only for appearance but also to ensure that the overhang of an articulated locomotive doesn't dent it.

If accessory and structure libraries are not available in the software, you can still use simple block diagrams to represent various accessories or rail side buildings. Similarly, reconfigured basic shapes and lines may represent various types of trees, boulders, lakes, and embankments.

Finish your track design work and then diagram your wiring with the software program. Transformers, wiring paths, and track connection points can be added to your track plan or, preferably, diagrammed as a separate layer. If you plan to include a block system with signals, these also may be diagrammed at this time.

Once all these elements are included in your layout design, it would be quite helpful if the software keeps a running tally or each item and its price so you have an initial shopping list.

In summary, computerized layout planning is an excellent investment for any scale modeler as it lets you quickly visualize your track plans in both two and three dimensions. As such it helps to reduce trial and error, facilitate changes, and stay in budget.

About this content:
Original authors: Douglas J. Hughes, Don Woodwell, & Steve Moore. Last revised on 2/3/2003.
Additional content posted by: Jonathan Bayer.
Questions/comments may be posted in the discussion tab.

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