US $5.95 • Can $7.95 - O scale trains

know to be equal to 63”. Now measure the distance betweenHorizontal B and C, again along Vertical A’. I got 1.1”. Usinga little high school algebra, solve the ratio 63/1.5 equals X/1.1the NYC (B&A being under lease to NYC at that time) is nowadded to our array. Railroads published these for employees tohave a ready reference as to the dimensions and operating characteristicsof various pieces of equipment, be they locomotives,freight cars, or passenger cars. Some railroads even had diagrambooks for standard track components, buildings, and signage.Since railroads were, understandably, very interested in clearancedimensions, this source is extremely useful for us. Again,hit the railroadiana shows, historical societies, or the Internet tofind these books. Be careful to get the ones printed in your era.Now, we’ll combine all our research material and see whatwe can build, still using my B&A H5 Mike as our example. Thisengine was built by consortium, the suspects being myself, BudJaggers, and the late George Dzicky. We had no drawings towork from of this particular engine, so the first step was to findphotos of both sides of the same locomotive (#1211) taken atapproximately the same date. Having my copy of the abovementionedNew York Central Locomotive Classification diagrambook from the period, we were able to get the major dimensions.Even without this info, we can still get close so long aswe know the size of, in this case, the drivers.Blow up the photo as big as you can stand. The bigger youblow it up, the better the resolution of your measurements.Using the photo of 1206 for an example, you can see that I’vedrawn lines at the tops (Line C) and the bottoms of the drivers(Line D), which I know to be 63” diameter. You can then gridup some vertical lines (Line A-Prime, written A’, as an example),again using the drivers for distance, crossing both original lines.Next, I made the relatively rash assumption that the main partof the running board is straight and parallel, so another horizontalline (Line B) was struck using that feature. In our case, sincethe H5 boiler isn’t tapered, we can use the top of the boiler foranother horizontal line (Line A). Take a good scale and measurethe distance along Vertical Line A’, between Horizontals C andD. In my blown up photo, the distance was 1.5”, which weand you can determine that the distance between HorizontalB and C is about 46”. Do the whole thing again to get the distancebetween Horizontal A and B, and whatever other lines,both vertical and horizontal, you want to add for the purpose.As you can see, you are starting to get references to majorparts of the locomotive based on some proportion of that knowndriver diameter. Measuring along these lines with dividers anda rule, followed by a little high school math, yields wisdom. Asyou keep building up this grid, you can get a reasonable idea ofdimensions, rivet line positions, and all the other stuff you careabout.Because most rolling stock photos you’ll find, especiallyfrom the steam era, are shot in a wedge or 3/4-view, you’ll haveto use this sort of stunt. The more dimensions you can get fromother sources, like our diagram book, the more accurate yourgridwork and other aids become. Also, you can project backany horizontal planes, such as running boards, driver tops, railhead,and the like to establish a projection angle. Again, sincethe H5 boiler isn’t tapered, we could use the top and bottom ofthe boiler. Use your school trig to project more lines forwardagain for more dimensions. If this all sounds like Greek to you,get a textbook on mechanical or technical drawing. Look upthe chapters on projections and teach yourself how to deal withthem.Before some genius writes to tell us that Scace is imperfectlyeducated, we concede that there are some errors inherentwith grid dimensions from photos. Because the locomotive istaller than the photographer, for example, parts on top of theboiler may scale out a little shorter than they really are. Inthis case, there is an angular error between the lens and thetop of the locomotive that we aren’t taking into account withour somewhat simplified method. The alternative is the use of40 • O Scale Trains - Sept/Oct ’04