Narrow gauge model railway scales and guages
There are dozens of combinations of model railway scales and gauges. NGMRSC serves five narrow gauge variants - three with one shared product range, one with two manufacturers, and a fifth with its own product range.
| Scale / gauge name | Scale ratio | Model gauge | Model mm per prototype foot | Precisely represented prototype gauge | Remark | NGMRSC collection |
|---|---|---|---|---|---|---|
| OO9 | 1:76 | 9.0 | 4.0 | 686 mm / 2'3" | Frequently used in United Kingdom. Often representing 2'0", 2'6", 1 metre, etc. gauges. | PECO OO9 / HOn30 / HOe collection |
| HOn30 | 1:87 | 9.0 | 3.5 | 783 mm / 2'5" | Frequently used in North America. Often representing 2'6" gauge. | PECO OO9 / HOn30 / HOe collection |
| HOe | 1:87 | 9.0 | 3.5 | 783 mm / 2'5" | Frequently used in Europe, often representing 600 mm, 750 mm, 760 mm, or 800 mm gauges. | PECO OO9 / HOn30 / HOe collection |
| HOn3 | 1:87 | 10.5 | 3.5 | 914 mm / 3'0" | Frequently used in North America, representing three foot gauge. |
HOn3 and Micro Engineering Company HOn3 collection |
| HOm | 1:87 | 12.0 | 3.5 | 1044 mm / 3'9" | Frequently used in Europe, often representing metre gauge. | Peco HOm collection |