Scale
Re: Scale
G-gauge track (aka #1 gauge) is a popular size for models now, and is 1.75 inches between the rails. Many narrow-gauge railroads overseas were built to meter gauge, or 39.37 inches between the rails. So models of meter gauge engines running on G-gauge track are built to a scale of 1.75 : 39.37, equivalent to 1 : 22.50
Dan Watson
Chattanooga, TN
Chattanooga, TN
- AnthonyDuarte
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Re: Scale
1/8th full size is another way of expressing a scale ratio of 1:8.
1:22.58 would closely represent standard gauge on 2.5" gauge track.
To determine inches-to-the-foot from a scale ratio, you just need to divide 12 by the ratio. 12/22.58 = .5314 (12/8=1.5 for 1/8 scale)
2.5" gauge track divided by .5314" inches to the foot (2.5/.5314) = 4.7045 represented feet, which is very nearly 4' 8.5".
Scale is not inextricably linked to gauge, so you could theoretically take this ratio and apply it to different existing track gauges to see what it works out to be. In gauge 1 (45mm), 1:22.58 would make the track represent 3.3327 feet, or 40" gauge. It's very close to meter gauge, however 1:22.2 is much closer for that. In 3.5" gauge it represents 6.58 foot gauge, so that's not too likely.
Hope this helps.
1:22.58 would closely represent standard gauge on 2.5" gauge track.
To determine inches-to-the-foot from a scale ratio, you just need to divide 12 by the ratio. 12/22.58 = .5314 (12/8=1.5 for 1/8 scale)
2.5" gauge track divided by .5314" inches to the foot (2.5/.5314) = 4.7045 represented feet, which is very nearly 4' 8.5".
Scale is not inextricably linked to gauge, so you could theoretically take this ratio and apply it to different existing track gauges to see what it works out to be. In gauge 1 (45mm), 1:22.58 would make the track represent 3.3327 feet, or 40" gauge. It's very close to meter gauge, however 1:22.2 is much closer for that. In 3.5" gauge it represents 6.58 foot gauge, so that's not too likely.
Hope this helps.
Re: Scale
Hoppercar...in the garden railroading part of the hobby, there are actually several scale factors out there. They are all closely related. Depends on which train manufacturer you were dealing with. Generally speaking...trains in that scale "range" are for the "G-gauge" train stuff. Carl B.
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I don't walk on water...I just learned where some of the stepping stones are!
I love mankind...it's some of the people I can't stand!
Re: Scale
I'm sure the O.P.'s question deals with the current topic "Decauville 0-4-0.." which is stated to be 2.5" gauge. So I think Anthony's explanation is correct. More commonly 2.5" gauge is associated with one-half inch scale, or 1:24 ratio, but calculating the scale and gauge more exactly, it is 1:22.58, analogous to 7.5 inch gauge guys using 1.6 inch scale to more accurately match the model with the track gauge. The oddball ratio is because the 2.5" track gauge doesn't exactly match half-inch scale.
Dan Watson
Chattanooga, TN
Chattanooga, TN
- AnthonyDuarte
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Re: Scale
It just occurred to me you can more simply multiply the track gauge by the scale ratio. 2.5" gauge track times 22.58 = 56.45" (56.5" is standard gauge)
Anthony
Anthony
Re: Scale
2.5” gauge for 1/2” scale is more of a British thing. Here in the U.S. designers such as H.J. Coventry designed their locomotives to 17/32” = 1’ scale on 2.5” gauge track.
Keith
Re: Scale
Interesting. If you divide 17/32 into 12 inches, you get exactly 22.5882353; maybe that’s where this comes from!
Dan Watson
Chattanooga, TN
Chattanooga, TN
Re: Scale
It's true that 1/2" to 1' was originally used in the UK for 2.5" gauge but it has been 17/32" to 1' since the 1920's. All the early 2.5" gauge designs by Henry Greenly and sold by Bonds of Euston Road, although advertised as 1/2" scale, are actually 17/32" to 1' and clearly marked as such on the drawings.
H J Coventry's 'President Washington' is actually 1/2" to 1' as is the Miller Hudson.
John
H J Coventry's 'President Washington' is actually 1/2" to 1' as is the Miller Hudson.
John
Secretary of The National 2½" Gauge Association
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Member of North West Liecestershire SME
http://www.modeng.johnbaguley.info