SCALE & GAUGE EXPLAINATION
Gauge and Scale are the two most commonly mis-used
terms by model railroaders. Many folks say that they model in a
particular
gauge. But gauge is not the correct term to use in that
case, and they should rather have said that they model in a particular
scale.
Here's why :
SCALE |
SCALE refers to the proportion of the prototype to the model. ( See note below ) |
GAUGE |
GAUGE refers to the distance between the heads (tops) of the rail of the track. |
Using S scale for example which is 1:64 the proportion
of the prototype, the "1" represents the prototype, and
the "64" represents the model, stating that the model is one sixty-fourth
the size of the prototype.
Though there are quite a few others, the following chart lists the most common scales that enthusiasts model in :
.
COMMON SCALES |
|||
SCALE |
OTHER DESIGNATION |
PROPORTION |
TRACK GAUGE |
A |
----- |
1:29 |
(51mm) (uses 1/32 scale track) |
F |
----- |
1:20.3 |
(45mm) (uses 1/32 scale track) |
G |
----- |
1:22.5 |
(45mm) (uses 1/32 scale track) |
H |
Half Inch Scale |
1:24 |
(45mm) |
HO |
(Stands for Half O) |
1:87.1 |
Standard - .649" (16.5mm) |
HOn2 |
----- |
1:87.1 |
2' Narrow Gauge - .276" (7.01mm) |
HOn3 |
----- |
1:87.1 |
3' Narrow Gauge - .413" (10.5mm) |
(None) |
Gauge 1 or #1 Scale |
1:32 |
Standard - (45mm) |
M |
----- |
1:13.7 |
(45mm) ( See * note below chart ) |
N |
----- |
1:160 |
Standard - .353" (8.97mm) |
Nn3 |
----- |
1:160 |
3' Narrow Gauge - .520" (6.35mm) |
O(17) |
----- |
1:45.2 |
? - 1.250" (31.8mm) |
O |
----- |
1:48 |
Standard - 1.250" (31.8mm) |
On30 |
O16.5, Oe or On2½ |
1:48 |
2' 6" Narrow Gauge - .?" (16.5mm) |
On3 |
----- |
1:48 |
3' Narrow Gauge - .750" (19.0mm) |
On2 |
----- |
1:48 |
2' Narrow Gauge - .500" (12.7mm) |
OO |
----- |
1:76.2 |
Standard - .750" (19.0mm) |
S |
3/16" Gauge/Scale |
1:64 |
Standard - .875" (22.2mm) |
Sn3 |
----- |
1:64 |
3' Narrow Gauge - .563" (14.3mm) |
TT |
"Table Top" |
1:120 |
Standard - .471" (12.0mm) |
TTn3 |
----- |
1:120 |
3' Narrow Gauge - .300" (7.62mm) |
Z |
----- |
1:220 |
Standard - .257" (6.52mm) |
.
The three "G" scale sizes below all operate on 45 mm "I" gauge track |
|
1:29 |
Standard gauge |
.
Regardless of what scale you are interested in modeling
in, below is an example of the
easiest method I have found for determining the size a model should be in
your scale.
.
Figuring Scale |
||
STEP |
DESCRIPTION |
EXAMPLE |
Step 1 |
Take ACTUAL measurement and convert it to inches. |
3' = 36" |
Step 2 |
Divide that measurement by the scale size you want. |
36" ÷ 64 (S scale) = 0.562" |
36" ÷ 87 (HO scale) = 0.413" |
||
36" ÷ 48 (O scale) = 0.75" |
||
36" ÷ 32 (I scale) = 1.125" |
||
Step 3 |
OPTIONAL : If possible, convert the answer to a fraction. |
1.125" equals 1-1/8" |
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To Model Railroad Topics Page |
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