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

Reply to
Dan
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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.

Reply to
Greg Procter

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.

Reply to
Greg Procter

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
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Go there for track standards, including flangeways, check gauge, etc. Wheel standards are found on
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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

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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

Reply to
Wolf Kirchmeir

Lionel "Standard Gauge" is 2 1/8" gauge, not 2 1/2". geezer

Reply to
Geezer

Thanks for the correction. But that 2-1/8" gauge was measured at the centre of the rails, was it not?

Reply to
Wolf Kirchmeir

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

Reply to
Geezer

Thanks for the responses, guys. I should have known there was no simple answer :)

My primary concern is safety. Boilers full of steam and hot water departing the rails uncommanded is not my idea of a Good Thing®.

Dan, U. Air Force, retired

Reply to
Dan

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.

Reply to
David Nebenzahl

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

Reply to
Geezer

Lionel tried to manufacture to the European standard but failed to recognise that it was measured rail centre to rail centre and therefore created a gauge that was 1/8" over the correct gauge. As he couldn't use the number designation he coined the term "Standard Gauge".

Greg.P.

Reply to
Greg Procter

On the first prototype French railways, the gauge was 1500mm centre-to-centre.

Reply to
Erik Olsen DK

Isn't there a uniform code for model boilers in the US? Leaving the rails is not so much of a problem as poor boiler construction, maintenance and operation.

Mark.

Reply to
marknewton

On 10/13/2007 1:32 AM Erik Olsen DK spake thus:

Again: why?

Reply to
David Nebenzahl

On 10/13/2007 5:42 AM marknewton spake thus:

Do you mean "code" as in building code or as in "model railroad advisory guidelines which are enforced by no one and which you are free to ignore"?

Reply to
David Nebenzahl

Sorry, I forgot to ask them when I was there in my time machine.

Reply to
Erik Olsen DK

On 10/13/2007 11:08 AM Erik Olsen DK spake thus:

Dang! Maybe next time.

Reply to
David Nebenzahl

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.

Reply to
Greg Procter

No, code as in legal code. Steam boilers are subject to regulations, one of which requires regular testing and certification by a qualified inspector. Etc.

HTH

Reply to
Wolf Kirchmeir

I mean code as in building code. Here in Australia full-sized boilers are regulated and licensed by the respective states - model loco boilers are similarly regulated and licensed by a national organsiation.

Cheers,

Mark.

Reply to
marknewton

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