Trying to get the various gauges and scales straight...

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yellow_cad
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Trying to get the various gauges and scales straight...

Post by yellow_cad » Mon Jul 13, 2020 8:29 pm

It seems that in descriptions of various locomotives, different size designations are used at different times. It is difficult to compare apples to apples. The fact that inch and metric are used does not help the situation. My general interest is with units that can operate on 45 mm track, but I would like to figure the entire system out. Thanks for any assistance. Jim

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ge_rik
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Re: Trying to get the various gauges and scales straight...

Post by ge_rik » Mon Jul 13, 2020 9:24 pm

I think this topic is best described as a can of worms ......

I'll take a first stab at it, but no doubt others will chip in and maybe even contradict what I say. But here goes.

45mm (or 1¾") gauge was originally devised for standard gauge models and called Gauge 1. The scales varied across the Atlantic between 1:29 and 1:32.

However, 45mm gauge has now been used for narrow gauge models and so the scale depends on the gauge being represented. So,
  • Metre gauge models on 45mm track = 1:22.5
  • 3 foot gauge on 45mm track = 1:20.3 or F scale or 15mm : 1 ft
  • 2 ft gauge on 45mm track = 1:13.7 or 7/8" scale or SE scale
  • Approx 2'9" gauge on 45mm track = 1:19 or 16mm : 1 ft scale or SM45
To complicate things, G Scale or G Gauge is often used by manufacturers to refer to almost any of the above

I hope that helps in some way

Rik
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-steves-
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Re: Trying to get the various gauges and scales straight...

Post by -steves- » Mon Jul 13, 2020 9:44 pm

^^^^^^^^^
Exactly what Rik said. Well done Rik, great explanation
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yellow_cad
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Re: Trying to get the various gauges and scales straight...

Post by yellow_cad » Mon Jul 13, 2020 11:25 pm

Thanks. It was very helpful.

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TonyW
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Re: Trying to get the various gauges and scales straight...

Post by TonyW » Tue Jul 14, 2020 9:57 am

I find these helpful...
Attachments
Scales.jpg
Scale Men.jpg
Tony Willmore
Rhos Helyg Locomotive Works: http://www.rhoshelyg.me.uk
Facebook: https://www.facebook.com/RhosHelygLocoWorks

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SeamusOD
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Re: Trying to get the various gauges and scales straight...

Post by SeamusOD » Mon Jul 20, 2020 1:34 pm

G scale and G gauge was the one that confused me at the start, by right every scale should be using its own gauge which is in fact also the correct scale, but many scales "borrow" a gauge to simplify things, and scales have developed because of the track sizes available.
No one intentionally decides to model in 1:20.3 scale they would select 1:20 much easier than using .0492341 in your calculations, but if you want to use 45mm off the shelf track and model in true scale then for 3ft narrow gauge thats your scale.
Personally I dont like larger models using a smaller gauge they always look like they are about to fall over. would be more in favour of going next gauge up than down, but personal opinion.
And as mentioned the mixing of imperial and metric really does add to the confusion, any wonder its always the "what is the difference between" first question of people coming into the hobby

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