I adapted this picture I found on another site and thought it might be useful to people trying to decide what kind of train they want.
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Size comparison of scales
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eljefe
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Why do these two HO cars look so different? I would not run these together … they almost look like different scales.
![Image]()
If the wheel gauge measurement is the same, the wagons are compressed in length dimension. If those are some scale of O scale , they are likely under-scale so they can negociate the unrealistic tight curves of O Scale track.
HO manufacturers do this as well, but compress in length only, usually to 1/93 or 1/100 scale.
HO manufacturers do this as well, but compress in length only, usually to 1/93 or 1/100 scale.
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Those are both HO….the short one is a scale 60ft, and the longer one is 72ft….there were different lengths of passenger equipment in the real world, so it wouldn’t be a stretch to run them together….although you’d probably never see a PRR car running with a Western Pacific car, now that would be more noticeable, IMO….
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I also switched from O to HO and was a little surprised of the size difference. I guess I expected HO to be a little larger! The O scale true ratio is 1:43.5. HO is 1:87. So HO is 1/2 in all linear dimensions. So if O scale object has linear dimensions L,W,H then the O scale volume is V = L x W x H. The corresponding HO scale volume v would be v = (1/2)L x (1/2)W x (1/2)H = (1/8)V. So the volume ratio between O and HO is 1:8! So I wondered what linear ratio would give me a volume that is 1/2 the O scale volume V. What is R so that (1/2)V = (1/R)Lx(1/R)Wx(1/R)H = (1/RRR)V, so R is about 1.26. So if I wanted a scale that would correspond to to half the O scale volume I would want a linear scale of 1/(43.5 x 1.26) = 1 / 55 (approximate). Which would be a little larger than S scale which is 1/64.
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Actually, I do believe O scale is really 1:48, not 1:43.5
I don’t know why you would want to worry about volumes, etc….I mean, if you wanted to replicate the exact stuff as the real cars in all the different scales, you’d never an able to do it….the weight would be the thing that gets you….
An H.O. scale 100 ton grain car would have to weigh 2,300 lbs…which of course would not be doable….
Unless, of course, I am missing something….it’s happened a couple of times in my life…. 😆
I don’t know why you would want to worry about volumes, etc….I mean, if you wanted to replicate the exact stuff as the real cars in all the different scales, you’d never an able to do it….the weight would be the thing that gets you….
An H.O. scale 100 ton grain car would have to weigh 2,300 lbs…which of course would not be doable….
Unless, of course, I am missing something….it’s happened a couple of times in my life…. 😆
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I wasn’t suggesting to scale by volume. I was just wondering what “linear” scaling would result in half the O scale volume. Weight or mass has nothing to do with it. I’m just concerned with linear dimensions not mass.
Yes I believe my O scale trains are scaled at 1/48. But I read somewhere in this forum that the original O scaling was 1/43.5 and this is were the HO “Half O” scaling 1/87 came from because 2 x 43.5 = 87.
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Can't always believe everything you read online, even in this forum, because the internet is ruled by the Wisdom of Socrates: "Wise men speak because they have something to say. Fools speak because they have to say something."
That said, I've read that elsewhere too.
That said, I've read that elsewhere too.
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From Wikipedia:
Scale is the ratio of a model dimension to the real life dimension. O Scale in the UK is commonly 1:43.5 or 7 mm to the foot, in continental Europe it is commonly 1:45 or 1:43.5 is also used particularly in France,[4] and in the USA 1:48.[3] Each region tends to design models to its own scale.[citation needed] The NMRA and the MOROP maintain detailed standards for a variety of scales to help model makers create interoperable models.[4][5]
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The problem with that photo, as with so many of that kind, is that while the little signs accurately show the size ratios, there is no reference object to enable the viewer to establish the scale in their heads (a much more useful reference on the Walthers website shows a dollar bill for comparison). [Edit: went to look for the Walthers page, and it's not the same. The original photo is on the summary page, not in the link. Walthers Model Railroading | Train Set Advisor ]
This particular exhibit also has some problems in the middle: it shows HOn3 and On3 as the same size ratios as the non-narrow gauge versions, but the locomotives next to those signs are clearly NOT in those scales. Part of the issue with this exhibit may just be that the locos are not all the same model, so size differences between the prototype versions may be blurring the size distinction between scales. Notice how the Walthers page linked above, while omitting some scales --probably for clarity -- uses the same type of loco for all scales).
This particular exhibit also has some problems in the middle: it shows HOn3 and On3 as the same size ratios as the non-narrow gauge versions, but the locomotives next to those signs are clearly NOT in those scales. Part of the issue with this exhibit may just be that the locos are not all the same model, so size differences between the prototype versions may be blurring the size distinction between scales. Notice how the Walthers page linked above, while omitting some scales --probably for clarity -- uses the same type of loco for all scales).
You are quite correct on several points. It was very difficult to obtain the OO American, TT, and T engines, and, to some extent the Z, as it is a cheaper but non working engine.. To get the same locomotive in all scales was nigh on impossible. No, forget the "nigh on" - it was impossible. So I did the best I could. It is a "side track" from my O scale layout done just for fun. It started when somebody at a train store dropped the G scale and they sold it for $65. (still runs, but I don't use it) It is perhaps more fun than accurate. Also, mixed in the collection are scale sizes vs. gauge differences which complicates the issue. I am sure that you are aware of the difference. Anyway, thank you for your insightful comments.... Happy tracks!
F units are unavailable in about half of what I collected. Besides, I you read my last post you will understand why I started with steam.... Thanks..
From my post, " It started when somebody at a train store dropped the G scale and they sold it for $65."I re-read that post several times, and I didn’t see where you talked about why you used steam….but maybe I’m missing something….
Its OK - no big deal. I would have been happy to compare any one diesel, but NONE are available in all these variations....
I was wondering if maybe a box car, caboose, or tanker might be available in all. Might be interesting to research.
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