Track standards for larger scales

Where can I find track standards for 2.5" and larger track gauges? I'm interested in data such as radii, switches etc.
Dan, U.S. Air Force, retired
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Dan wrote:

I don't think there are any published standards. I'd guess that model engineering groups and clubs set their own standards.
So long as trains just run around circuits without complex pointwork, all that's needed is treads/tyres of suitable width set at the correct spacing for the track gauge and suitable flanges to keep the wheels on the track. It's only when turnouts etc are encountered that checkrails and flange backs etc have a guiding effect. As 2.5" to 7.5" gauge rolling stock is generally "ride-on" and straddled, turnouts are not a problem.
If you're going to build a private railway system in isolation then I'd suggest you work with scaled-down prototypical dimensions. Probably only the flange depth can be increased without having to adjust other interacting dimensions on wheels and track.
Regards, Greg.P.
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Dan wrote:

PS: 2'5" is "Scale/gauge 3", (64mm) and is available commercially (Germany and Britain that I know of). It is the same _scale_ as LGB narrow gauge (1:22.5) but of course the models are to standard (4'8 1/2") gauge.
Regards, Greg.P.
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Dan wrote:

2.5" gauge was called "standard gauge" back in tinplate days. It is not a scale model railroading gauge, however, ands AFAIK never has been. It's not clear why you want to know about this gauge, nor what scale you contemplate running on it, but I'm assuming that you intend to model standard gauge in a scale that suits the track. If so, the following remarks may be helpful.
The closest scale modelling gauge representing standard gauge (4ft 8.5in) is 2.78" at a proportion of 1:20.3. It is the largest scale/gauge listed under NMRA standards on http://www.nmra.org/standards/S-3_1ProtoTrackwork.html Go there for track standards, including flangeways, check gauge, etc. Wheel standards are found on http://www.nmra.org/standards/S-4_1ProtoWheels.html .
NMRA calls this F scale at 15mm to the foot. The Brits use 16mm to the foot, because it works out nicely for using O gauge (32mm) for 2ft narrow gauge. You may find useful parts and kits by searching for this scale.
There are no recommended practices for track curvature for this gauge, but extrapolating from the published ones on http://www.nmra.org/standards/rp-11.html suggests the following:
Streetcars etc: min radius about 20" Logging and industrial roads: min. radius about 50" Small locos (eg, 0-6-0) and cars to about 50ft: min. radius about 80" Typical steam locos of transition era, cars to about 70ft: min radius about 100". Large steam locos, cars to 90ft: min radius about 160"
NB that the assumption is that your are modelling standard gauge.
Tinplate 2.5" gauge is something else entirely. It was made by Lionel and others. These manufacturers measured the gauge to the centre line of the tubular rail, so that the actual gauge between the rails was less (about 2-1/4" IIRC.)
2.5"/2.78" gauge could represent a narrow gauge in a larger scale, if you are thinking about live steam. If a desire for live steam is lurking behind your question, I suggest searching for live steam sites and manufacturers. The smallest commercial live steam gauge for is 3.5" (ignoring such oddities as Hornby's OO scale effort of recent memory,)
HTH
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Lionel "Standard Gauge" is 2 1/8" gauge, not 2 1/2". geezer

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Geezer wrote:

[...]
Thanks for the correction. But that 2-1/8" gauge was measured at the centre of the rails, was it not?
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Lionel catalogs through 1936 describe their track as 1 3/8" and 2 1/4" between the rails for O and Standard gauge, respectively, which were as you mention, center of rail to center measurements. In 1937, the catalog correctly lists O as 1 1/4" gauge, but persisted in calling the Standard gauge as 2 1/4". In 1938, they finally got it right and listed the two gauges as 1 1/4" and 2 1/8". The Standard gauge track was always 2 1/8" between the rail heads in spite of the catalog authors. Geezer

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On 10/12/2007 7:59 AM Wolf Kirchmeir spake thus:

>

>>

>>

That's got to be one of the strangest "standards" I've ever heard of if true (not disputing it if you say so). Why on earth would anyone specify gauge in terms of center-to-center spacing? The actual gauge would depend on the thickness of the rails, and measuring the gauge that way would be a bitch and a half.
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One must remember that Standard gauge trains were toys, not scale models. One theory for the measurement is that the earliest toy train track used strips of steel with no "head" placed in slots cut half way down through the wooden ties, so the idea of measuring center to center could have carried over from that. Also, when they did move to formed sheet metal "tubular", the rail head was round, so the bright line on the top of the rail where the trains ran on was the rail center. The listing in the catalog was perhaps more to tell parents how big the toy was going to be. The listing served to tell whether the Ives or Dorfan or American Flyer toy would run on the same Lionel track, so as long as all manufacturers used the same erroneous measurement, the objective would be served. All the competition had ceased making Standard gauge by the time Lionel reverted to calling the gauge the correct 2 1/8". Geezer

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David Nebenzahl wrote:

On the first prototype French railways, the gauge was 1500mm centre-to-centre.
--
Venlig hilsen
Erik Olsen
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On 10/13/2007 1:32 AM Erik Olsen DK spake thus:

Again: why?
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David Nebenzahl wrote:

Sorry, I forgot to ask them when I was there in my time machine.
--
Venlig hilsen
Erik Olsen
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On 10/13/2007 11:08 AM Erik Olsen DK spake thus:

>

Dang! Maybe next time.
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David Nebenzahl wrote:

Sometimes you've just got to accept that things were done the way they were. For any given situation there is always more than one form of logic that can be applied. For example, and I'm guessing here, one could think in terms of where the load is applied between vehicle and track surface - that would be in the centres of railhead and tyre. Obviously weight carrying is the major function of the rail/wheel interface and guidance is a secondary function.
Greg.P.
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Why? Have you ever seen a Citron auto?
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On 10/13/2007 5:03 PM video guy - www.locoworks.com spake thus:

Ah, you mean Citron. Yep, seen 'em.
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Hook your tape measure over the outside of one rail and measure to the inside of the other rail - Center to center distance. Measuring from inside to inside you might need long arms or an assistant.
--
Bill Kaiser
snipped-for-privacy@mtholyoke.edu
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On 10/15/2007 8:36 AM snipped-for-privacy@mtholyoke.edu spake thus:

Still doesn't make sense. As I understand it, laying track isn't the same as, say, spacing roof trusses or some other carpentry job. Don't they make fixed track gauges for laying rail, instead of depending on someone's tape measure?
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David Nebenzahl wrote:

It doesn't make sense because you're looking at the problem the wrong way around. It happened, so ask yourself 'why did they do it that way?' instead of asking 'Why didn't they do it the logical/normal way?' Back then there wasn't a 'normal way' so they did it as they thought best.
Regards, Greg.P.
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On 10/15/2007 2:22 PM Greg Procter spake thus:

Point taken; it's easy to be perplexed about such things from our "advanced" perspective.
But still: you'd think that even way back then in the Neolithic Railroad Epoch that the smart guys who designed early trackwork would have figured out that since the thing was based on the flanged wheel, the crucial parameter was the *inside distance between rails*. It's this distance that determines whether or not the damn train falls off the tracks or not (well, mostly).
Anyhow. I guess it just has to be one of those mysterious things.
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