Why are there so many different sizes/scales of O gauge?

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ChinaHaun19

New Member
I shop for and play with my O gauge setup the most of all. I live in the United States. And I quickly began noticing that the scale, or size, of rolling stock and locomotive varies dramatically. What is the deal with that? It makes shopping especially online kind of sketchy.

Id Love to know in detail what’s up with that!!
 

Selector

Well-Known Member
I shop for and play with my O gauge setup the most of all. I live in the United States. And I quickly began noticing that the scale, or size, of rolling stock and locomotive varies dramatically. What is the deal with that? It makes shopping especially online kind of sketchy.

Id Love to know in detail what’s up with that!!
The answer lies in the difference between 'scale' and 'gauge'. The gauge is merely the distance between the rails. You could run 'narrow gauge' G Scale rolling stock on HO scale tracks, but it would look funny. It would work, but it would look less than narrow gauge.

If the items you are looking at specify, or claim, that they are of a certain scale, that might be a point of contention, and there could be lots of disagreement. Scale items should have high fidelity to the prototype that they represent, at least in terms of dimensions and general looks. But they might operate on 'gauge' track that could be any gauge the manufacturers/importers choose.

Remember that there's O gauge and O Scale. The former often includes tinplate and the popular three-rail rolling stock and locomotives with the shoe under the frame. They can be widely varied in 'scale'. On the other hand, O Scale items should be very close to the real items in looks and run only on two rail O gauge.
 

Iron Horseman

Well-Known Member
I quickly began noticing that the scale, or size, of rolling stock and locomotive varies dramatically. What is the deal with that? It makes shopping especially online kind of sketchy.
It can be summed up in a few words. Space, Cost, and Marketing.

Going back to the 1940s and 1950s a two bedroom 1 bath house of 900-1200 square was considered the norm. "No one" had enough room for a 60" circle of track for a toy train. If they were really lucky they had a basement or an attic where the trains could live. For these folks O-27 was invented. They could throw out a circle of track in the hall or space between the dresser and bed. To go around such tight corners they made the locos and cars much shorter than a "scale" 1:48 would be.

Even if one was not constrained by the lack of space there was the lack of money. A good 1937, Lionel 700E Hudson would have run something like the equivalent of $3000 in today's money. Not many people had that much liquidity back then. Solution, make smaller cheaper, units.

All the vendors wanted to use as many things as possible to get folks to buy their trains. So they made trains slightly larger than O-27 and came up with terms like semi-scale, near scale, or even just highly detailed ignoring the size altogether. Didn't really matter if the size matched anything or the detail was real or just painted on. Result was pure chaos in the o-gauge world.
 

Mixed Freight

New Member
Knowing what to buy in O-gauge for a beginner unfortunately takes a fair amount of study and practice. After spending my whole life totally ignoring O-gauge/O-scale, I first started getting into 3-rail O-gauge about 10 years ago. I've learned quite a bit in the last ten years, but still don't know everything, unfortunately. I will say one thing, a great place to learn about various sizes is to shop for used stuff at train meets. I have learned a lot and scored some really good deals that way. And do some research on the internet. There are several various sites and blogs that discuss the different sizes and show examples.

Speaking of still not knowing everything, I recently ordered three box cars from an internet supplier. One was true 1/48 scale, and I knew that upon ordering it. As for the other two, I thought one was traditional-sized (approx. 1/56 scale), and the other was O27-sized (approx. 1/64 scale). As it turned out, after receiving the order, the other two BOTH ended up being O27-sized. Not a big deal, I kept all three because I liked them anyway. It just goes to show, that even though I'm semi-retired now, you're never too old to learn something. 🤪
 

kjd

Go make something!
O scale started out as 7mm/ft, 1:43.5(ish). Later, the Americans switched it to 1/4in/ft, 1:48. The track gauge didn't change so 1:48 trains now run on 60" gauge track instead of 56.5" unless you model Proto48. HO was half of O so became 3.5mm/ft. I wish TT had done better, it is a very convenient 1/10in/ft, 1:120.

To get large O scale trains to run on tight corners, models for that market were made shorter. Is that what you meant Paul (mixed freight) when you said some were 1/56 or 1/64 scale?

S scale is 1:64, 3/16in/ft.
 

Mixed Freight

New Member
O scale started out as 7mm/ft, 1:43.5(ish). Later, the Americans switched it to 1/4in/ft, 1:48. The track gauge didn't change so 1:48 trains now run on 60" gauge track instead of 56.5" unless you model Proto48. HO was half of O so became 3.5mm/ft. I wish TT had done better, it is a very convenient 1/10in/ft, 1:120.

To get large O scale trains to run on tight corners, models for that market were made shorter. Is that what you meant Paul (mixed freight) when you said some were 1/56 or 1/64 scale?

S scale is 1:64, 3/16in/ft.
Yup. A lot of O27 trains can scale out at somewhere around 3/16" = 1'-0". And a lot of traditional-sized trains tend to scale out approximately half way between 1/48 and 1/64 scale, which puts them at around 1/56 scale.

Notice I said "can", "somewhere" and "approximately". There's no rhyme or reason to a lot of their exact sizes. Sometimes they stretch or compress one or two dimensions more than a third dimension (i.e., L x W x H). The only thing they have in common is that they all run on O-gauge track.
 




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