Q: What is HOn3 scale? If it uses HO scale track (1:87 gauge), it seems the rolling stock must be scaled wider and taller. Conversely, if I modify an HO scale/gauge locomotive for narrow gauge, I’ll need to build new, narrower track. Help me understand this. – Mark Dice
A: Hi, Mark. Your second guess is the right one. HOn3 is the same size as HO, except for the track.
It’s easy to mix up the concepts of scale and gauge. (Our friends over in the toy train world who refer to their O scale trains as “O gauge” may have something to do with this.) The “HO” in HOn3 indicates that the trains are HO scale, which is a proportion of model to prototype of 1:87.1. This is the same no matter the gauge of the track.
The “n” in HOn3 stands for “narrow gauge.” In other words, the track gauge is narrower – in this case, 3 feet between the railheads, rather than the standard gauge of 4 feet, 8.5 inches.
So while the motive power and rolling stock of an HOn3 railroad is slightly smaller than HO scale equipment, that’s because the equipment on the prototype was generally built slightly smaller than that of standard gauge railroads. It’s the same proportion, though, and all other components of a narrow gauge model railroad – from structures to vehicles to figures – are the same size.
Narrow gauge was very popular around the turn of the last century, when it was widely believed that the narrower right-of-way and lighter equipment of narrow gauge would lead to lower costs on land purchases, lighter rail, maintenance, and operation. Though some narrow gauge railroads were notably successful – such as Maine’s several 2-foot-gauge short lines and Colorado’s Denver & Rio Grande – most soon discovered that the slight savings were more than offset by the cost of maintaining nonstandard equipment and the inability to interchange cars with standard gauge railroads. Most narrow-gauge railroads in the United States went bankrupt, converted to standard gauge, or were bought out by larger railroads. (The prototype I model in HO scale, the Cincinnati, Lebanon & Northern, did all three.)
Narrow gauge railroads are popular with hobbyists for several reasons. Among them are the allure of modeling unusual equipment, like the Rio Grande Southern’s Galloping Goose; the picturesque and dramatic scenery and terrain often traversed by these railroads; the romance of modeling an earlier era; and the ability to fit more model railroad into the same space than could be accomplished in standard gauge. (Narrow gauge trains can usually negotiate tighter curves and sharper turnouts than standard gauge equipment of the same scale.)
Pioneers of narrow-gauge modeling often selected their track gauge so they could use the locomotive mechanisms, track, wheelsets, and trucks of the next smaller scale. On30, for instance, was originally O scale models on HO scale track, which works out to just over 31” gauge, not 30”. Today, though, modelers have a wide selection of commercial narrow-gauge products in numerous scale/gauge combinations like HOn3, On30, and Sn3.
If you think you might be interested in building a narrow gauge model railroad, look into Tony Koester’s book Guide to Narrow Gauge Modeling, which is available in the Kalmbach Hobby Store.
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I have been modeling in HOn3 and Sn3 for a few decades now. One of the biggest misconceptions I hear over and over is that HOn3 runs on N scale track. It does not. HOn3 runs on track properly gauged to 3 feet in 1/87 HO scale, N scale track gauge is too narrow. Same with Sn3, it does not run on HO scale track, it runs on Sn3 track properly gauged to 3 feet in 1/64 scale. People are constantly confusing gauge with scale.