S Scale and S Gauge Model Railroad Trains

American Flyer and Beyond

HO-scale model railroad

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S scale is often regarded as synonymous with the American Flyer brand of model railroad trains. S scale is defined as 1:64 or 3/16ths of an inch to one foot, and the S scale's track gauge is an unusual 0.884 inches. S scale trains are manufactured in both AC and DC varieties, but unlike O scale, both types use a two-rail track. Once on the brink of extinction, S scale railroading has experienced a renaissance in the last two decades. 

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    The S Scale Standard

    The S letter designation for the scale was defined by the National Model Railroading Association (NMRA) in 1943. S scale (1/64) was specified to be one-half of One scale (1/32). One scale is another rare older scale. Incidentally, the name O scale derives from the fact that it was originally called "zero scale" because at 1/48 it was smaller than One scale. In the early days, this scale was commonly referred to as the 3/16th scale.

  • 02 of 10

    S Scale vs. S Gauge

    In model railroading "scale" refers to the relationship between the size of a model and its original prototype. The term "gauge" refers to the space between the rails of the train track.

    While beginners often use these terms interchangeably, American model railroaders usually refer to the "scale" they work in, while UK railway modelers will talk about their "gauge." Ironically, the usages of the terms "gauge" and "scale" have become culturally reversed. The National Association of S Gaugers, Inc. (NASG) is an American institution, while the S Scale Model Railway Society is based in the UK. This may be because early 3/16th scale models shared 1.25" gauge three-rail track with 1:48 O scale trains.

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    Early History

    While some historians write that there were modelers in the UK working in the 3/16th scale before the 1930s, the emergence of the 3/16th scale in America seems to have happened independently of their efforts. It seems likely that the early UK models were unmotorized models for static display.

    During the mid-1930s Cleveland Models introduced 1:64 scale model railroad trains in the United States. For a time, the 3/16th scale was referred to as the "CD" scale for "Cleveland Designed." CM produced static display models, but powered chassis kits for them soon followed. The best known CM locomotives were a PRR 0-6-0 switcher and a Chicago Great Western 4-6-0 Ten Wheel. Today one running CM locomotive is still purported to exist.

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    A.C. Gilbert and American Flyer

    In 1938, A.C. Gilbert (later the manufacturer of Erector Sets and other educational toys) acquired The American Flyer Manufacturing Company (established in 1910). Up until that time, American Flyer manufactured O scale model railroad trains. After they were acquired by the A.C. Gilbert Company in 1939, the brand name "American Flyer" was used on A.C. Gilbert's new 3/16th scale trains. Gilbert most likely obtained permission to manufacture in the scale from Cleveland Designs; in any case, there is no record of Gilbert producing any O scale trains from that time forward. Interestingly though, its HO trains were sold under the name Gilbert HO, not American Flyer. A.C. Gilbert continued to manufacture American Flyer S scale trains until 1966.

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  • 05 of 10

    Prototypical Accuracy

    Although A.C. Gilbert began producing 3/16th scale trains in 1939, these were not true S scale models. These early trains used the O scale 1.25" gauge track. Model train manufacturer Marx soon followed with its own 3/16th scale trains for O gauge tracks. This led to the introduction of O27 trains, though American Flyer never offered O27 products. But these trains established Gilbert as a pioneer of prototypically correct scale model railroading. Unlike other fanciful toy trains of the day, Gilbert's 3/16th scale locomotives were scale models of the actual PRR K5 class 4-6-2 and the NYC J3 "Hudson." In 1946, keeping with this push towards realism, American Flyer trucks and mechanisms were changed to 0.884" gauge, and true S scale/gauge was born.​

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    The Lean Years

    From the demise of A.C. Gilbert in 1966 through the 1970s, S scale modeling declines; interest in S scale was probably kept alive initially by a small newsletter called the "S Gauge Herald." Later the National Association of S Gaugers (NASG) was formed. These organizations, and another small magazine called the "S Gaugian," provided the means for S gaugers to exchange information and keep abreast of the offerings of small S scale manufacturers like Kinsman, Miller Laboratories, and Enhorning. Most of the products were kits. This is analogous to the state of the TT scale in America today. 

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    The S scale renaissance began around 1980 when American Models appeared on the scene with an S scale ready-to-run EMD FP-7 diesel. They soon followed up with a set of streamlined passenger cars, and later freight cars. This paved the way for a return of S to the model railroading mainstream. As the makers of the TT scale in America apparently never learned, no scale can succeed without ready-to-run products. Since these initial offerings by American Models, there has been a slow but steady increase in the availability of S Scale ready-to-run products.

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    American Flyer Today

    In 1967, the American Flyer brand name was acquired by the owners of Lionel, LLC. While the American Flyer brand name fell into disuse during the lean years, the renaissance in S scale has induced Lionel to offer American Flyer S scale trains again. In 2008 the American Flyer line occupied about a dozen pages in the Lionel catalog. Some modern American Flyer offerings are now equipped with Lionel's TMCC digital controls and RailSounds audio systems, but they also offer recreations of a few classic American Flyer products too.

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  • 09 of 10

    Other Modern S Scale Manufacturers

    Today, S scale trains and accessories are manufactured by several companies. Most notable among these are American Models, who started the renaissance, and S-Helper Service Inc. Both of these companies advertise their trains as "American Flyer Compatible." S-Helper offers attractive starter sets with included integrated roadbed track, S-Trax. Products from both of these companies appear to be competitive with better O scale and HO scale products in detail, quality, and price.

  • 10 of 10

    S Scale in Brass

    For the discerning collector, River Raisin Models, Pennsy 'S' Models, Overland Models, and others make finely detailed S Scale trains in brass. Of course, these come at prices you would expect to pay for brass.