What does 'gauge' mean?

The sizes of the Models we are interested in are designated in rather odd ways, no doubt for good (but abstruse) historical reasons.

We have x inches to a foot, which is OK if you are familiar with inches and feet. But such folk are dying out, and only ever existed in the Empire.

We also have engines (etc) which have a gauge - usually in inches (see above), but which do not relate directly to the size of the model but to the width apart of the wheel flanges.

A good example is in the latest ME, p 309 - where a track is described as 'slightly more than a quarter of Standard Gauge', but the engine is 'one third scale'. Clear, as long as you know what Standard Gauge is. But adverts in the same magazine refer to devices which are 2", or 5", and a Garrett Tractor in 6" scale. Now this does not run on rails, so what does this mean? Is it rather small compared with a 7 1/4" locomotive, and a bit big alongside a 5" one? Or could it be possibly 6" to the foot? Or even half size, 1:2 or 50%.

I know that this will create no problems for all you folk who have been making models since we actually had an empire, in fact secret jargon like this can help to promote the sense of community and one-up-man-ship for those already in it. But it is no help at all for beginners (of any age) and must confuse foreign readers no end. And we wonder how we can get new blood into the hobby?

I am not suggesting we should abandon traditional methods - what I say is needed is a standard universal scale description which is used in addition, when arcane scales are stated.

The idea of a ratio is, I think, universally understood. And so, I suppose, is a percentage. They are just different ways of saying the same thing. So, carry on using gauge, in inches, where what you need to know is whether your model will run on someone else's track. But PLEASE add the ratio or the percentage of full size in brackets as well.

Too hard for you to work out? Just think how hard it is for someone who was born and bred with metric gauges and a metric system throughout.

Regards, Tim

Edited By Tim Stevens on 11/02/2018 15:58:50

You could always go for Metric Standard Gauge - 1.5352 metres (or thereabouts)!

John

Then there are also those easy to understand metric scales used by figure modelers, I like to make 120mm figures but some are bigger than others as it depends who sculpted the original as the 120mm can either be taken to the eyes or the top of the head. Bring back 1/16th scale

The gauge of something - anything - is a measure of the device, item or whatever.

A petrol gauge in a car usually measures only fractions of fullness of the fuel tank.

The gauge of a shot gun is the number of lead balls (of a specific density) which, when produced from exactly one pound of that lead, are the size of the barrel.

Pressure guages normally have an indicated range.

Rain guages collect water and read off in inches or mm, normally. The collector is much larger than the calibrated vessel.

There is clearly no connection between any of the above guages. Model engineering is no different in that respect.

A railway track was gauged by the width of two horses rear ends, side by side, but is now usually defined in inches for Imperial sized model railways.

There are 12 inches to a foot - no variation on that one! (x is usually an unknown value which needs to be calculated from an equation, or the abscissa on a graph).

As guages are specific to the measurement under discussion, a 6” scale model cannot be compared to a rail guage - no more than the rail guage is comparable (in absolute units) to any other gauge (like a shotgun or pressure gauge).

Clearly, with model trains they have both a scale and a gauge and most people only refer to the one aspect which seems important to them at the time. No different than beekeepers who denote hive boxes as ‘broods’ and ‘supers’ when they are actually deep and shallow boxes (and each can be, and are, used as either brood or honey boxes, dependent on the beekeeper). No different than sloppy electical notations for the cross sectional areas of conducors.

Whenever anyone asks me to spell ‘it’ or ‘that’, they get exactly what they asked for!

I used to know a professional figurine sculptor who told me the purpose of all these scales was to prevent what he called size creep, that there was a tendency for all of the successive range to get slightly bigger over time, without necessarily realizing it.

Michael W

Edited By Michael-w on 11/02/2018 17:39:54

As far as railway modelling goes (that is both passenger hauling and scenic) the standardisation on gauge rather than scale was established by a toy manufacturer in the late 19th century. Over time time this has provided many more problems for the smaller scale scenic modellers.

To be honest Tim - I wasn't really sure what your post was actually about?

Are we going over the Imperial vs Metric discussion again? We've had it here many times before - and you are not a "newbie" here by any means.

I use both measurement systems but I still think in terms of MPG and know that I am about 5ft 10in tall. I have to interpret the Weather Man for my wife because she has no idea (or interest in learning) what 2.5cms are. I intend to make very sure that my Grandson also speaks "Imperial" (as well as Metric) - and for that matter - telling him all about our "Imperial" history (both the good and bad parts). He's just noticed the photo of his Great-Grandfather (in his RAF uniform) and I will do my best to explain all that to him too.

If your question is purely technical - then it seems to me you have confused "Gauge" with "Scale" which seems to be a common mistake. A "Gauge" is simply something one can 'gauge' with - but in Railway terms it normally refers to the distance between the rails (in the past it sometimes referred to the distance between the 'centres' of the rails)

"Standard" gauge refers to UK/US (etc) railway tracks of 4ft 8" (1ft 2" less than my height). If you wish to build a scale "standard" gauge model - the "scale" is arrived at by dividing the model track gauge into the full sized one, so 2.5" track (e.g. Gauge '3' ) has a "scale" of 1:22.6.

Most non-railway models do not have a "Gauge" per-se - but if modelled on an original prototype - they will have a "Scale" which is most easily notated by a ratio (e.g. half-scale, 1/10th scale or 1:2.6 ect).

I hope this will help clarify things - but perhaps not.

Regards,

IanT

Edited By IanT on 11/02/2018 18:24:29

Given you've got standard gauge wrong you may need to double check your height as well.

Andrew

Begging your pardon, a considerable amount of 'in use' technology is American based, and to that end we still teach imperial measurements in machining to current apprentices.

Most American military equipment up until just recently is imperial based and as we need to repair / maintain it, teaching that form of measurement is necessary.

Oh, and 'gauge' is the width between in rails and may be either metric or imperial.

Regards

Lofty

Most areas of human endeavour end up with a specific vocabulary that is used in depth by the experts who need it, and to a lesser extent by the public in a simplified form. You just lean the half dozen meanings you need.

I started with 8in, then 5in, then it was 3 or was it 3.25 all obsolete now and the 5in we used in our product became a 3in, and now 2 1/2 in to make the product smaller. No idea what I'm talking about? "Discs" and suddenly it all becomes clear, but only because you have picked up a bit of that jargon along the way - you were never taught it in school.

For railway models gauge is the distance between the rails.

Scale is the ratio between model and full size. You can model different scales using the same gauge and vice-versa, just as full size (1:1) locos use various gauges.

When scale is give as a measurement 'x' this USUALLY shorthand for 'x to the foot' even when 'x' is specified in metric units. So 3" is 3 inches to the foot (1:4) and 4mm is 4mm to the foot (1:76).

As Jason has mentioned, this goes out of the window with figure models where the height often bears a loose relation to figure height.

Neil

Contrary to what might be thought of about imperial measurements, If anything I actually enjoy the opportunity to learn about what something means rather than being off putting and I suspect anyone else in the hobby also enjoys it. As they say it would be all quite boring if everything was the same.

The Americans also carry it on, and there are a number of times with these units and scales where I think "I actually find that more logical than ours."

Michael W

Yes Andrew,

I'm afraid with age you do tend to lose the odd 1/2" or so I'm afraid...

Regards,

IanT

There's an interesting page on Metrication in the United States in Wikipedia.

Roger

From the topic title I thought it was going to be a question about gauge pressure and absolute pressure.

Martin C

Models of monorails have no gauge but they have a scale. An example of gauge versus scale is HO/OO. HO (half O ) has the same gauge track as the British OO but the scales are different. HO gauge have accurate proportions between the loco bodies and the track (1/87th scale). OO trains have bodies too big proportionally (1/76th) for the width of the track. This is because the UK manufacturers who embraced OO at its introduction after the war feared they couldn't source sufficiently small electric motors so they expanded the loco bodies instead.

Edited By Chris Trice on 12/02/2018 18:08:02

I was taught the width of railway lines was based on the width of Roman Chariot wheels, is this correct?

There's also EM, P4 and Scale4 which are all more or less OO to various levels of accuracy.

And my brother models in 00-9 which is narrow gauge to OO scale on N-gauge track >boggle<

Neil

Urban myth, I think.

Brian

No - I'm sure that Roman Chariots had wheels Brian...

IanT