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"S" Scale History

by Craig S. O'Connell

Back in the 30's, the heyday of "O" gauge, some model railroaders began searching for a smaller scale that would take up less space but retain the advantages of detailing and the heftiness of modeling that O afforded. To them HO was too small and so it was generally conceded that a more desirable gauge would be found somewhere between O and HO, thus the 3/16" scale came to be. It appears that 3/16" to the foot trains were first made in the United Kingdom in 1919 when Charles Wynne created teh M.R. 4-4-0 No. 999 locomotive, held in existence today by the S Scale Model Railway Society of the UK. For more info see the SSMRS S scale history page at

What we do know is that S scale 3/16" model railroading was conceived in the U.S., not by A.C. Gilbert, as popular legend might have us believe, but by Ed Packard. In the late 1920s Mr. Packard owned a model airplane company known as "Cleveland Model and Supply." At about the same time as the 1933-34 Chicago World's Fair, considered by the staff at Model Railroader magazine to be the event that really launched the hobby of model railroading, Mr. Packard started a magazine called "Cleveland Model News." S scale free lance historian Richard Douglass notes, "Issue number 1 was the Jan/Feb 1933 issue, and some of the issues published that first year contained plans for railroad freight cars. The real gem for S scalers is the Winter 1934 issue, which came out in the first quarter of 1934, exact date unknown. This issue contains an article on how to build a 3/16 scale model of the then revolutionary UP streamliner train, with accurate plans. How long the 3/16 scale model kit project was in planning at Cleveland Models is unclear, but it likely took a year or two to gear up for production kit releases in 1937. His kits were released as "C-D" scale (Cleveland Designed) into the so called "battle of the scales", where many versions of O, HO and OO scales were fighting it out. Cleveland Models produced 3/16 kits for several years but failed to gain a foothold in this highly competitive model railroad market. By the onset of World War II, it was clear that the winners were the long established O scale, and the up and coming HO. Cleveland Model's 3/16 trains were not a success, but his model airplanes kits were a great success and have a following to this day."

Thus, during its infancy, 3/16" model railroading became known as "C-D", originating from the term "Cleveland-Designed," the trademark of Mr. Packard's Cleveland Model & Supply Co., preceding A. C. Gilbert Company's line of American Flyer™ trains. As Douglass noted above, it was 1937 when Packard began marketing 3/16" scale wood and embossed paper kits. A year later he marketed two powered locomotive kits -- a CGW 4-6-0 and a PRR 0-6-0 switcher. (Click on the Loco names to see scanned 1938 pictures from my original 1938 catalog). These, along with his wood-and-paper Milwaukee Hiawatha train, are in great demand by S scale collectors. Some years later, the National Model Railroad Association (NMRA) recognized the scale and renamed it "S" because of the sibilants in three-sixteenths (scale) and seven-eighths (gauge).

At a subsequent 1942 NMRA meeting the designation "S" was formally adopted for 3/16" scale model railroading. It is thought that the "S" was derived from words such as Seven-eighths in the track gauge or three-sixteenths in the scale. Of course S scale has come a long way since then and is now enjoying a renaissance in production.

In the late 1930s the New Haven, CT manufacturer, A.C. Gilbert Co., bought the American Flyer O gauge line from a Chicago based company. Pre-war American Flyer ran on 3 rail O gauge track but had S gauge bodies. By 1941 all production was halted and the company went into war time production. In 1946 the company returned to manufacture toy trains but now they were S gauge trains run on two rail S gauge track. For more info on this development Click here..

Much of the information on the history of Ed Packard and his "C-D Models" was provided by NASG member Richard Douglass.


New to this page - S scaler Dick Karnes has provided some interesting information on the history of passenger cars produced in S scale since 1937. Please click here to take you to that partial production list.

For a history of the National Association of S Gaugers CLICK HERE.

Edited by Craig S. O'Connell

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Some Helpful Definitions

American Flyer Conversion--The process of converting AF tinplate equipment to hirail or scale usually by changing couplers, trucks, wheelsets and other detail parts.

Couplers--Most popular today are the Kadee and knuckle. Kadees are preferred by scale and some hirail operators because they appear more prototypical. Kadee makes an S scale #802 and an HO #5 (both suitable for S scale). Knuckle couplers are popular on AF trains and most hirail products. Early AF also came with link couplers but were abandoned in the early 50s for the knuckle couplers.

Current-AC--Alternating Current. Most AF locomotives operate on alternating current but, with universal motors, can run on DC (direct current) too.

Current-DC--Direct Current. Most scale and hirail equipment operates on direct current offering smooth operation. By reversing a switch on the control panel a DC engine will reverse instantly.

Flange--the portion of any railroad wheel that guides that wheel down the rails. Deep flange models are considered hirail.

Gauge--refers to the spacing between the rails as measured from the inside of one rail head to the next. The standard gauge for most American railroads is 4 feet 8 1/2 inches. Roman chariot wheels used the same dimensions.

Kit Bashing--A process by which a modeler uses more than one kit to build a model and mixes parts of kits for a finished product.

Radius-Minimum--This depends upon the track you are using. The radius of American Flyer curved track is about 19".
American Models code .148 sectional track uses a radius of 27".
Most scale modelers prefer a minimum radii upward of 36".

Rail Code--used as a measurement of rail height. Code .100 means the rail height is .100 inches or 100 thousandths of an inch. Some model railroaders mix rail codes using the lighter and smaller rail in the yards and the heavier higher rail on the mainlines. You can mix codes as long as the tops of the rail meet. This can be done by shimming the smaller code rail. Smaller rail codes require wheels with smaller flanges. In S scale code .100 = 110# (pound) rail while code .125 = 155# (pound) rail.

Roadbed--The part of the layout just below the track.

Scratchbuilding--Building models "from scratch" using an assortment of materials including wood, styrene and metal.

Trucks--The wheels, axles and sideframes of a piece of equipment. Sprung trucks have actual coil springs on the sideframes as opposed to ones simulated in metal or plastic.

Turnout--Where two diverging tracks join; sometimes called a switch but this word also refers to toggle switches and the like. The term switch is also considered the moving rails part of the turnout. It is a sub assembly of a turnout and contains the points.

Turnout Points--the rail portion of a turnout that moves to change the tracks route. Points are the two individual rails that are beveled and meet the stock rails to deflect the flanges in the direction of travel.

Turnout-Frog--the point at which the rails of a turnout actually cross is called the "frog" part. It looks a lot like the legs of a frog.

Turnout-Open Frog--a turnout assembly where the point rails are hinged, insulated or bridged. Prototype railroads use open frog turnouts. American Models code .148 turnouts are open frog.

Turnout-Closed Frog--a turnout where the point rails are all one floating assembly. Best used on pikes where both hirail and scale equipment are used. I use them on my layout for scale and hirail operations.

Frog Number - i.e. #6 Turnout or Frog--The frog number of a turnout is simply the ratio of the diverging route measured against the straight route. The rails of a #6 turnout are one inch apart, six inches from the frog. The rails of a #8 turnout are one inch apart, eight inches from the frog, etc... A #6 turnout is sharper than a #8. See illustration below.

Frog to determine:

Measure out one inch from the two rails as in the photo shown at left. Then measure in inches (on the straight rail) back to the frog point. If you've measured back 6 inches then you have a #6 turnout.


Feeder Wire--smaller gauge wire (usually #22 or #20 - the lower number is thicker wire) that feeds from a main wire under the layout up to various points along the track to preclude voltage drops and maintain constant current. Some modelers will put feeder wires just beyond rails that are joined. The idea here is that you cannot always rely upon the rails to carry constant current from one section of rail to another.

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Modelers new to the hobby often ask about comparative rail size and how it is proportioned to the prototype rail used on American railroads. The first chart below illustrates how a particular size rail is approximately equivalent to an S scale track. Therefore, 90 pound rail would be equivalent to .088" high S scale rail. The "code" of a piece of model rail is the height of the rail in thousandths of an inch. Code 100 is 0.1 inches tall.


S scale
















Base Width








Head Width








Here's another way of looking at it with a comparison to other scales. Note that the dimensions of the prototype are AAR (American Association of Railroads) standards.

Theoretical rail conversion chart AAR section Height ------Scale height in inches------ lb per in yard inches N TT HO S 48:1 O 140 7 6/16 .046 .061 .084 .114 .152 .163 132 7 1/8 .045 .059 .082 .111 .148 .158 115 6 5/8 .041 .055 .076 .104 .138 .148 100 6 .038 .050 .069 .094 .125 .133 90 5 5/8 .035 .047 .065 .088 .117 .125 80 5 .031 .042 .057 .078 .104 .111 70 4 5/8 .029 .039 .053 .072 .096 .103 60 5 1/4 .027 .035 .049 .066 .089 .094 50 3 7/8 .024 .032 .046 .061 .081 .086 40 3 1/2 .022 .029 .040 .055 .073 .078 Practical rail conversion chart *(shows closest model rail equivalent readily available) Rail code ------Closet equivalent scale weight------- number N TT HO S 1/4 O 172 --- --- --- --- 156 148 --- --- --- --- 132 125 --- --- --- 156 100 100 --- --- 156 115 75 83 --- --- 132 90 55 70 --- 156 100 65 35 55 156 115 75 40 --- 40 115 75 40 --- --- * This chart is based on "equivalent readily available" in 1969
source: "Model Railroader", April, 1969.

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Who Are We?

American Flyer


S gaugers are a diverse lot. Some of us are tinplaters, some hi-railers and others scale modelers. Tinplaters collect and operate American Flyer S gauge trains. Manufactured by the A.C. Gilbert Company of New Haven, Connecticut from 1946-1966, American Flyer is often considered synonymous with S gauge. In fact many of us started out as youngsters whose dreams were fulfilled when that American Flyer train appeared under the Christmas tree. Unlike the competitor O gauge Lionel, American Flyer trains operated on two rail sectional track. Operating accessories, realistic "choo-choo" sounds and smoking steamers were characteristic of American Flyer. Today many S gaugers still operate their old reliable American Flyer trains either out of nostalgia or for the sheer fun of it all. Still others are collectors of the highly prized items found stored away in attics or passed down from one generation to the next. Indeed, American Flyer has been a name to be proud of.

Hirail Meets Scale
Doug Peck's American Models Hi-Rail PA-1 meets Wayne Hills' Omnicon Models Scale F-7s on Bristol S Gauge Railroader's Hi-rail modular layout. Bridge scratchbuilt by the late John Porter. Photo by Wayne Hills.


But S gauge is not just made up of American Flyer enthusiasts. Contrary to what many model railroaders believe, there is a large segment of the S gauge community who build and operate perfectly scaled models with exacting precision and detail. S Scale modelers operate on code .125 track or lower with scale flanged wheelsets and the more realistic Kadee couplers.

S scale layout of Bill Marks II and Bill Marks III of Pleasant Valley, NY. Bill, Sr. heads up the NASG Clearinghouse.


While the term Hi-rail is often used synonymously with American Flyer tinplate, that is really a misnomer. Hi-railers lie somewhere within that vast range between scale and tinplate. The two features that characterize hi-railers are the size of the track (code .125 or higher) and the size of the wheelsets. Beyond that you will find hi-railers whose models are sometimes even more highly detailed than the scale modelers as well as those whose models are more toylike in appearance.

And remember, S scale (and gauge) is the ONLY American model railroad scale (gauge). All others were imported from Europe!

Brooks Stover's Buffalo Creek & Gauley S hirail layout in Rochester Hills, MI.

Photo by Terry Harrison.

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Partial Production List of S Scale Passenger Cars by Dick Karnes

There has been an amazing variety of passenger cars available in S scale since the scale’s inception in 1937. Here is a partial list:

C-D Models (kits, wood with lithographed cardstock sides & trucks, wooden wheelsets):

Complete MILW Hiawatha train
Pullman 85’ heavyweight 12-1

Dayton Models (unpainted kits, wood with brass sides, ends, trucks; white metal details):

NYC gas-electric combine

River Raisin Models (R-T-R brass):

Pullman 54’ troop sleeper
ACF 54’ troop kitchen
NYC 54’ converted troop sleeper express car

Super Scale Models (unpainted kits, copper sides & ends, brass floor, wood roof, brass trucks, white-metal details):

NYC heavyweight 60’ baggage
NYC heavyweight 60’ RPO
B&O 75’ heavyweight combine
B&O 75’ heavyweight coach
ATSF heavyweight diner
Pullman 85’ heavyweight 12-1
Pullman 85’ heavyweight 14-section sleeper
Pullman 85’ heavyweight observation
Pullman 85’ heavyweight solarium
Wooden 60’ open-end combine
Wooden 60’ open-end coach

SouthWind Models (R-T-R brass):

13 DB heavyweight Pullman
12-1 heavyweight Pullman
NYC 70’ heavyweight standard coach w/6-wh. trucks
NYC 70’ heavyweight standard combine w/4-wh. trucks
NYC 70’ heavyweight standard combine
NYC 70’ heavyweight standard observation
60’ heavyweight RPO 3-3
60’ heavyweight RPO 4-2
60’ heavyweight RPO 3-3/4-2
65’ heavyweight Harriman coach
60 heavyweight Harriman RPO
60 heavyweight Harriman baggage car
various Harriman variations (look up)
NYC “Swallowtail” 75’ heavyweight observation (“Pacemaker”)
PRR R50B express reefer
NYC express reefer
NYC milk car
Rutland milk car
Reading express boxcar
PRR P-70 75’ heavyweight coach
PRR B-60 60’ round-roof heavyweight baggage
PRR B-60 60’ clerestory-roof heavyweight baggage

American Models (some with SHS seed money) (R-T-R plastic):

70’ NYC heavyweight baggage
70’ NYC heavyweight RPO
CNJ 70’ heavyweight combine
CNJ 70‘ heavyweight coach
CNJ 70’ heavyweight observation
Pullman 85’ heavyweight 12-1
Pullman 85’ heavyweight 10-1-2
CNJ 85’ café car
NP Pullman 85’ lightweight smooth-side coach (kit) - also painted as Amtrak Heritage coach
NP Pullman 85’ lightweight smooth-side combine (kit) - also painted as Amtrak Heritage combine.
NP Pullman 85’ lightweight smooth-side observation car (kit)
NP Pullman 85’ lightweight smooth-side sleeper (kit)
NP Budd 85’ lightweight smooth-side dome coach (check this!) (kit) - also painted as Amtrak Heritage dome coach
Budd 74’ lightweight RPO (NYC Empire State Express)
Budd 74’ lightweight coach (NYC Empire State Express)
Budd 74’ lightweight diner (NYC Empire State Express)
Budd 74’ lightweight observation (NYC Empire State Express)
Amtrak Superliner baggage-coach
Amtrak Superliner coach
Amtrak Superliner diner
Amtrak Superliner diner
Amtrak Superliner sleeper
Amtrak 50’ utility boxcar

Train Stuff (unpainted kits, urethane & wood kits, white-metal trucks):

70’ heavyweight baggage
70’ heavyweight RPO/baggage
CNJ 70’ heavyweight combine
CNJ 70‘ heavyweight coach
CNJ 70’ heavyweight observation
Pullman 85’ heavyweight 12-1
CNJ 85’ café car

Chester Industrial Arts (unpainted kits, wood frame, aluminum sides & ends):

Pullman lightweight corrugated baggage (60’ & 85 ‘)
Pullman lightweight corrugated RPO (60’ & 85 ‘)
Pullman lightweight corrugated combine (60’ & 85 ‘)
Pullman lightweight corrugated coach (60’ & 85 ‘)
Pullman lightweight corrugated roomette (60’ & 85 ‘)
Pullman lightweight corrugated observation (60’ & 85 ‘)
Pullman lightweight corrugated diner (60’ & 85 ‘)

JC Models (unpainted kits, wood with aluminum sides, white-metal ends & details):

Pullman lightweight corrugated baggage (60’ & 85 ‘)
Pullman lightweight corrugated mail-baggage (60 & 85 )
Pullman lightweight corrugated RPO (60’ & 85 ‘)
Pullman lightweight corrugated combine (60’ & 85 ‘)
Pullman lightweight corrugated coach (60’ & 85 ‘)
Pullman lightweight corrugated roomette (60’ & 85 ‘)
Pullman lightweight corrugated diner (60’ & 85 ‘)
Pullman lightweight smooth-side baggage (60’ & 85 ‘)
Pullman lightweight smooth-side mail-baggage (60 & 85 )
Pullman lightweight smooth-side RPO (60’ & 85 ‘)
Pullman lightweight smooth-side combine (60’ & 85 ‘)
Pullman lightweight smooth-side coach (60’ & 85 ‘)
Pullman lightweight smooth-side roomette (60’ & 85 ‘)
Pullman lightweight smooth-side diner (60’ & 85 ‘)

Exacta Models (unpainted kits, copper sides & ends, brass floor, wood roof, white-metal details):

Pullman light-weight 85’ cars
Budd light-weight 85’ cars
B&O 75’ heavyweight coach

Models by Miller (unpainted kits, photoengraved brass with wood roof kit):

85’ heavyweight parlor car
Pullman 85’ heavyweight 10-1-2
Pullman 85’ heavyweight 12-1
Pullman 85’ heavyweight observation
Pullman 85’ heavyweight diner

Kinsman Scale Models (unpainted wood kits):

B&M/NYNH&H 61’ wood baggage car
B&M 61’ wood combine (open vestibule)
B&M 61’ wood coach (open vestibule)
NYNH&H wood combine (closed vestibule)
NYNH&H wood coach (closed vestibule)
50’ wood express reefer (various roads)

Sylvania/Midgage (unpainted kits, unpainted extruded aluminum, white-metal ends & trucks, wood floor)

Pullman lightweight 67’ baggage
Pullman lightweight 85’ combine
Pullman lightweight 85’ diner
Pullman lightweight coach, double windows (67’ & 85 ‘)
Pullman lightweight coach, paired windows (67’ & 85 ‘)
Pullman lightweight 85’ roomette
Pullman lightweight observation (67’ & 85 ‘)

Midgauge Models (wood kit, embossed prepainted cardfstock sides and ends):

GN 50’ express reefer

Schreiner Scale Models (unpainted urethane copies of the Sylvania/Midgauge cars, unpainted bodies):

Pullman lightweight baggage (60’)
Pullman lightweight combine (85 ‘)
Pullman lightweight diner (60’ & 85 ‘)
Pullman lightweight coach, paired windows (60’ & 85 ‘)
Pullman lightweight roomette (60’ & 85 ‘)
Pullman lightweight observation (60’ & 85 ‘)

Scenery Unlimited (unpainted urethane body kits):

B&M/NYNH&H 61’ wood baggage
NYNH&H 61’ wood 65’ wood RPO
NYNH&H 61’ wood combine
NYNH&H 61’ wood coach

Josh Seltzer (urethane 1-piece casting with AM floor):

Budd 85’ lightweight coach

Ed Loizeaux (unpainted kits, wood frame, plastic-coated cardstock sides and ends):

Pullman 85' smooth-side coach
Pullman 85' smooth-side baggage car
Pullman 85' smooth-side observation

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Changes last made on: August 21, 2006.




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NASG Bernie Thomas Award, 2003


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