Why Scales And Gauges Cause Confusion

May 17, 2008

The terms scale and gauge are two of the most confused terms in the model railroad hobby.

The SCALE proportion is expressed as a fraction of a real life-sized railroad. As an example, HO scale is 1/87 the size of real life-sized railroads.

For model trains, track GAUGE is the width between the inside running edge of the rails. For toy trains, gauge is the measurement from the center of the two outside rails.

Do Tracks Have The Same Gauge?

No they don’t, but there are two main types: standard gauge and narrow gauge. In the US, Canada and most European countries, trains run on standard gauge.

Here is an email I got from a reader:

“I am continually frustrated with retailers who are either unaware, or refuse to recognise the difference, for commercial reasons. Whilst most English manufacturers of OO SCALE models now match HO model manufacturers and use HO GAUGE wheel sets, the scale size difference still remains. I take umbrage with those who list their English models as OO/HO. You can maybe get away with buildings and lineside models, but not rolling stock!

Put an HO SCALE loco alongside a OO SCALE loco of the same prototype and the difference in size sticks out like a sore thumb. I got caught again recently and bought a remarkably well-made model of a New Zealand 2-6-4 Tank, advertised as HO SCALE. It is not, despite the retailers avowed belief that it was, in fact, HO. It seemed massive alonside my Bachmann HO SCALE 2-8-4’s and 4-8-4’s.

It is in fact OO SCALE on an HO GAUGE chassis and this is the common cause of much confusion by many ill-informed sellers. Please use your influence to try and help ‘eradicate’ this problem.”

Thanks to Edwyn for that contribution on scales and gauges.