This can be a confusing topic and frankly, most of the confusion is brought about by people who do not understand the relationship between Scale and Gauge and then use them incorrectly. So from all my research, here is how a very clear topic became so catawampus that even many train dealers donâ€™t really understand what they are saying and use the words scale and gauge incorrectly.
First I will cover what should bring no arguments; because there is nothing to disagree about.
Scale: Is a proportion from the original size. The prototype, often abbreviated as proto, a real locomotive.
Gauge: The distance between the insides of the rails. For â€œStandard Gaugeâ€ in the US, the proto distance would be 4â€™ 8.5â€ or 1435.1mm
From here, everything starts to get a little muddy because you are dealing with the first element of confusion; two standards. One from Europe (where the first working steam locomotive was built and many of the large scale trains were conceived), NEM (Normal European Modelling) and the second from the US, NMRA (National Model Railroad Association) who doesnâ€™t seem to like large scale trains.
It appears that rather than saying the scale of the model you wanted (like 1:87.1) is was much easier to say and remember letters (like HO). So for a 1:64 scale (3/16â€ = 1â€™) train, they decided to call that â€œSâ€ scale. For 1:48 scale (1/4â€ = 1â€™) they decided to call that â€œOâ€ Scale (see Note 1). For 1:87.1 (3.5mm = 1â€™) they decided to call that HO (half O scale) (See Note 2). And for my beloved MTH 1:32 Scale (3/8â€ = 1â€™) they decided to call that â€œ1â€ scale.
Note 1: The second element of confusion is that some letter designations (like O scale) have different scales sizes in different countries. (Somewhat like â€œGâ€ but different) In Great Britain and France; it is 1:43.5. In Germany, Japan, Russia, Czech it is 1:45. In the US it is 1:48 scale.
Interestingly, O scale was originally called â€œ0â€ Zero Scale (1 â€“ 10 were larger scales already in use in Europe), because 0 (aka. O) was a step down in size from 1 scale (My beloved MTH) they called it zero scale. From the 1920s until after World War II, 0 scale dominated the model train market. But as model trains became more affordable for the average person, the space required to set up the tracks became a major consideration in purchasing model railroad trains so sizes (scales) got smaller. It is easy to see how the Zero scale morphed to O scale because it happens today when people say their ZIP code which is all numbers; like 17078. Instead of saying One Seven Zero Seven Eight they will frequently say One Seven Oh Seven Eight. The third element of confusion; is it a letter or a number???
Note 2: Although the HO nomenclature was meant to be half of the O scale, because the size originated in Europe, the metric system did not successfully become exactly one half of O. The fourth element of confusion; combining English and Metric measurements.
Now comes the fifth element of confusion; people calling a gauge by the scale name because of the standard prototypical relationship. People with track that has a gauge of 31.8mm (1.25â€) started to say I have O gauge track. What they really mean is that 1.25â€ track is the gauge that O scale reflects when wanting to make a â€œstandardâ€ railroad (not narrow gauge). The sixth element of confusion comes when you use that same 1.25â€ track for models in Europe that call there models: 16mm scale (actually 1.19.05 scale) or Fn3 scale (Actually 120.3 scale) or Scale 7 (actually 1.43.5 scale) ARE YOU REALLY CONFUSED NOW? Wait, it gets worse!
The seventh element of confusion. The model railroad community is mixing and matching different scales with different gauges to replicate narrow gauge railroads faster than girls mix and match their clothes. Youâ€™ll read more on this later.
Now, to the heart of the matter, and my eighth element of confusion; â€œGâ€ or large scale. There are several accounts as to what â€œGâ€ stands for. Some say it is from the Note 3: This link states that 1 scale was also a US scale. https://support.modeltrainstuff.com/hc/en-us/articles/202970203-What-are-the-different-Gauges-and-Scales-What-do-they-mean-
Because people quite often mix and match terms without a great understanding of the words they use, the 45mm track is most often referred to as 1 gauge. But as you know, they use the same track associated with 1 scale (1 Gauge / 45mm) to operate all the other large scale trains. Did you know that for LGB (1:22.5 scale), the â€œstandardâ€ gauge track for that scale is actually 3 gauge track which is 63.5mm. However, in the US, they use 1 gauge track for all large scales (except 1:32 scale) to replicate a narrow gauge railroad. In the case of LGB, its proto would be operating on 40â€ track. Aristocraftâ€™s 1:29 scale, for standard gauge, is best suited for 2 gauge track 50.8mm.
â€œSo Larry, if 1 gauge track got its name from being associated with 1 scale trains (the scale of 1:32); can you really call it 1 gauge track when it is track that is being used by a 1:22.5 train?" I say, "Call it what you want, but if my cat had kittens in the oven I wonâ€™t be calling them biscuits!â€ (Meaning it should no longer be called one gauge track when it is being used by any train that is not 1 scale / 1:32 scale)
As you can see, it is very confusing when people talk about model trains; especially when mixing and matching scales and gauges.
In conclusion, there is no â€œoneâ€ scale named G; just a bunch of large scales that fit into a category that people call â€œG.â€ And I find it hard to accept we should still call a track width by the scale name it was associated with (1 scale) when you are using it with another scaleâ€¦it should just be called 45mm gauge track.
Remember, although your trains may fall into the G category; not all G category trains are 1:32 scale, or 1:29 scale or 1:22.5 scale.
Comment: Mikeâ€™s Train House (MTH) refers to their 1:32 product line as â€œRailking One Gaugeâ€ trains. From a technical standpoint, this is incorrect as they sell 1:32 scale trains (1 scale); not track associated with that scale commonly referred to as 1 gauge. In easier terms (?), they are calling their 1:32 train by a term used for distance (gauge) versus what a 1:32 proportion is called; â€œscale.â€
Want to get an idea of how convoluted model railroading has become with the
scale/gauge relationship? Check out the links below: