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Creating the Drawings - Preliminary Steps

The drawings on this site are now into their third decade, with the first 1:880 "tiny trains" completed in 1998. But what actually goes on behind the scenes in their creation? Read on below!

Drawing Process

Research and Selection

The first step is research. Before making any drawings, I gather reference material - scouring the Internet (and books) for rosters, detail photos and diagrams. For many locomotive models, I'll find and classify photos of almost every railroad variation in order to establish phase and production details. A lot of the phase details and spotting features listed in the Descriptions and Phases are the result of original research, but I also rely heavily on other sources (such as the Unofficial EMD Homepage) for rosters and production information. I've attempted to list as many reference sources as possible in both the Links section and in the Descriptions and Phases pages as they've been updated in recent years.

I tend to start with the familiar: Each time I've started a new drawing scale, the first drawings were second-generation EMD units, largely because I was more familiar with them than almost anything else. Even when I've had detailed mechanical diagrams to work from, I've generally still familiarized myself with the locomotive (or car) in question more generally before drawing it. This can be a challenge with first-generation diesels since many were sold with few options across a huge number of railroads, and I've sometimes elected to just draw a "generic" version instead.

In the case of modern locomotives that are still in production, I'll generally refrain from creating or mentioning "phases" until the production run is complete. I'll also often (but not always) refrain from drawing the most recent version until some small detail has changed - so I don't have to keep on updating the roadnumber ranges.

At left: An example of my folders for reference images, in this case for the MLW RS-18 for which I have some 300 images separated into 20 folders. Derivative models with few variations require much less reference material; for the GE Dash 9-40C I have just a couple dozen photos and no subfolders or diagrams (since I derived it from the Dash 9-44CW). In contrast, for the the EMD SD40-2 alone (not including the SD40-2F, SD40-2(W) or SD40T-2) I have over 1,200 images in about 80 folders.

Reference Images

I specifically look for two photo types: "As-built" photos (of any size) taken as close as possible to the date of manufacture, and higher-resolution detail photos from any date or railroad. I've taken advantage of various trips to museums to extensively photograph and measure preserved locomotives and rolling stock.

The reference material often determines what models or variations I draw first. For instance, since I took a huge number of MMA C30-7 detail photos starting around 2006, the C30-7 was the first GE locomotive model I drew in the 1:36 series in 2008. Likewise, since most of the EMD SD50 detail photos I've found are of DRGW and UP units, the first version I've drawn in all three scales is a DRGW variation. As I've moved into larger scales, I've often given a bit of extra priority to whatever didn't make it into the previous scale.

Reference material has also been the biggest determining factor in what doesn't get drawn - at least in 1:36 and 1:18. As a rule, I don't omit or "fudge" the smaller details that may not be clearly visible in photos (and which are often absent from diagrams). I also won't make a drawing unless I'm fairly certain I can get the dimensions sufficiently accurate. For this reason, there are some more obscure models I drew in 1:55 that I'm not (yet) able to re-draw in 1:18.

If after gathering reference material I find that I don't have enough, I'll put that particular model on the back burner and do fresh searches for new material every few years. In the case of the GE P42DC, I had basic dimensions going back to the 2000's and many of my own detail photos from 2013-2014, but wanted a bit more reference material to fill in the underframe details (especially since they were unique compared to other GE units). Waiting a bit longer paid off, since in early 2022 I came across a P42DC parts catalog that provided better reference material than I ever imagined I'd have.

As of early 2024, the "Reference Images" folder on my hard drive contains about 52,000 files in 3,900 folders - which doesn't include most of my own photos (which are stored separately by date) nor everything from a couple of large batches of files forwarded to me separately (which I haven't yet merged into my own filing system). I don't delete reference files after finishing drawings, except for duplicate copies of my own photos.


I try to use as many exact dimensions as possible. Dimensions are commonly shared across many locomotive models, and I make sure that common components line up exactly across different drawings. For instance, the EMD standard cab follows the same basic design from the GP35 to the SD60, so the cab outline and dimensions are the same in all my drawings of these models.

Sources of Dimensions

Diagrams and real-world measurements have benefited many models in the 1:18 series. Many of the diagrams I've used for reference were freely available online and I simply found them from many hours of browsing. However, I've also been sent large numbers of reference photos and diagrams from site viewers, including Nick O'Dell, Jones Rana and James Walton, for which I'm immensely grateful.

The 1:18 GP30 drawings - among my earliest 1:18 drawings - were the first locomotive drawings on the site that I derived almost entirely from EMD mechanical drawings, including cutaway diagrams of the trucks, underframe, cab and most of the hood (supplemented with photos). In 2013, I also started taking detailed real-world measurements of preserved locomotives; the 1:18 MLW M-636 drawings were the first drawings to benefit from such measurements. Several series of 1:18 drawings (mostly MLW locomotives) have benefitted from these measurements, and several other models remain to be done.

mlw m636

An illustration of some of the measurements I took of a preserved M-636 for use in the 1:18 MLW M-liner drawings. This locomotive benefitted from more detailed real-world measurements than most of the other locomotives I've drawn. For more measurements, see the Locomotive Dimensions page.

Measuring Photos

In the absence of detailed dimensional data, I use the main dimensions as a baseline and derive the rest of the measurements from similar models or from photos. While I can scale the drawings from a relatively small number of main dimensions, it requires very good photos from specific angles to do so.

If you visit the Trainiax photo section, you'll find that many of my photos are direct side views taken through a telephoto zoom lens from as far back from the track as possible. I take photos like these specifically as reference for the drawings, since they provide the closest perspective possible to a direct side view. Once I have a few key dimensions from diagrams or data sheets—at a bare minimum, truck centers, wheelbase, wheel diameter, overall height and length—I can isolate the rest of the dimensions using simple ratios between the photos and drawings. This only works if a) the photo is without lens or perspective distortion and b) the listed dimensions are actually correct.

I also intentionally slightly overexpose many photos so that the underframe detail is more visible.

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A typical series of photos I've taken of one locomotive (a CN Dash 9-44CWL) that I use as reference for the drawings.

Here is a downsized crop of the first Dash 9-44CWL photo above, showing how I might measure something such as the walkway height. CN diagrams list the Dash 9-44CWL walkway height as 67.625", which is lower than other Dash-8 and Dash-9 locomotives. Measurements from the top of the rail will often vary considerably as wheels wear - on this unit, the wheels (normally 42") are so heavily worn that they would reduce the walkway height by about 2" compared to new wheels. I therefore always measure the walkway height from the axle centers, which tends to be pretty consistent.

Based on the truck wheelbase (13' 2", or 158") and the pixel measurements from the photo (758 px wheelbase, 223 px axle-to-walkway height), the axle-to-walkway measurement works out to about 46.5". Adding 21" (the radius of a new wheel) gives a walkway height measurement of 67.5", which closely matches the nominal dimension of 67.625".

photo measuring

Measuring the walkway height based on the truck wheelbase.

Once a few major dimensions are established, all the rest of the hood details can be scaled against known dimensions using this method. However, even with a zoom shot such as the ones above, perspective distortion from the varying depth of the components can be enough to throw off measurements if it's not accounted for. I also don't tend to measure using perpendicular dimensions unless I have to - walkway height is an exception, but generally I prefer to obtain a vertical dimension from another nearby vertical dimension.

Dimension Convergence

Simple photo measurements work for smaller dimensions, such as hood doors and air intakes. However, for unpublished key dimensions, I often rely on several different sources converging to the same figure. This is especially true when a series of models has a gradual progression of different dimensions, which can result in very complicated dimension-matching issues.

As an example, almost every GE unit from the early Universal series to the present-day GEVO units has something in common with both the previous and subsequent series. Therefore, before beginning work on any 1:18 GE locomotives, I wanted to establish the progression of dimensions (especially height) as the models evolved. However, I had only few solid height dimensions to work from, including the six-axle Dash-7/Dash-8 walkway height (75"); the Dash-7 cab height (105" above the walkway); the Dash 8-40CW walkway height (69.75"); and the wide-nose cab height for Dash-8 and later units (114.375" above the walkway). The central hood height for GE units is not listed in railroad diagrams, likely because it is lower than the cab, so I had to find a way of determining the hood height while matching all these dimensions up between different models. These measurements were further made more difficult by the top of the hood being rounded instead of flat.

Based on the Dash-7 cab height of 105", I used photos to derive a central hood height of 102" above the walkway, which I thought was common to all GE units prior to the AC6000CW and Evolution series. But when I tried to combine a 102" hood with a Dash-9 cab (drawn at 114.25") and Dash-9 radiators (scaled from photos), they did not line up: the hood was too high. However, as it happened, I had just taken photos of a C30-7 and C39-8 from the same angle at the same location, so I tried measuring them - and discovered that the hood and engine room doors on the Dash-8 were 1 inch lower than on the Dash-7. Using a 101" hood height solved the problem in the Dash-9 drawings I was working on.

Finally, I tried bridging the gap between the Dash-7 and Dash-9 series by comparing these dimensions to later standard-cab Dash-8 units (the C39-8 and other early Dash-8s still retained some Dash-7 dimensions). The figures I had found suggested the six-axle Dash-8 walkway was lowered by 5.25" between the Dash 8-40C and Dash 8-40CW (75" to 69.75") to account for the taller wide-nosed cab. Subtracting 5.25" from the wide-nosed cab height (114.375") suggested a standard cab height of about 109". When I used a few B39-8 photos to extrapolate the standard cab height based on a hood height of 101", I arrived at a cab height of 109". The figures matched.

All these figures (outside the four initial dimensions) are estimates from photos, but with the dimensions converging exactly I've settled on using them in my 1:18 GE locomotive drawings.

You'll find more information about the accuracy of the drawings in the Drawing Accuracy section.

Next up: Undecorated Drawings