The 7mm Narrow Gauge Association aims to encourage the modelling of
narrow gauge railways at a scale of or around 7mm to 1 foot (1:43)

Modelling the Narrow Gauge

From a modelling perspective, one distinct advantage of narrow gauge prototypes is that many were short, so in the smaller scales it is quite possible to model the features of an entire railway. Narrow gauge lines were also no strangers to tight curves, so what looks so out of place on a main line layout is prototypically normal on a narrow gauge layout.  The drawing below shows how one typical narrow gauge coach profile in 7mm scale compares to a standard gauge coach in the most common scales.

Comparison of standard and narrow gauge modelsSo where does the would-be narrow gauge modeller start? Almost anywhere, is the unhelpful but realistic answer. This page will focus on the options in the scales supported by the Association, around 7mm to the foot. Trade support for the scales supported by the Association is limited when compared with OO/HO and N scales, for example, but there is plenty out there, especially from the more specialist suppliers. Association members have access to a trade directory with details of many relevant suppliers. Association sales supply many items and, of course, mainstream O scale accessories, figures and scenic items are all relevant for use. For further details about Association Sales can be found by following this link.
You may find it helpful to download a copy of our booklet 'An Introduction to 7mm Narrow Gauge Modelling'. Just use this link.

The Association also publishes a handbook 'Getting Started in 7mm Narrow Gauge' and you can download some sample pages using this link. More details of the content and how to buy it can be found here.

One way of starting is to buy a layout and/or rolling stock second-hand. Association Sales has an active second-hand department that can help you with this and member's advertisements in the member's supplement 'Narrow News' which is despatched with our 'Narrow Lines' magazine every two months often contains advertisements from members for layouts that re being disposed of.
The principal scale/gauge combinations supported by the Association are summarised below, with some basic notes, essentially from the U.K. viewpoint. More details on other scale/gauge combinations, both for 7mm scale and in other scales can be found on this page [under development]. Note that O scale is generally taken as 1:43.5 for 7mm to the foot unless otherwise noted.


Using readily-available 9mm gauge track and N scale mechanisms, this is typically used to represent two types of railway:

  • Small industrial lines serving agriculture for example
  • Miniature railways, principally for recreation/tourism, a major example being the Ravenglass & Eskdale in Cumbria
There is some trade support for locomotive and rolling stock bodies. 


For those who wish to portray the true 2ft gauge in 7mm scale, there is very limited trade support. Track, locomotives and rolling stock are likely to be hand-built although there are kits available that can be built to 14mm gauge as an alternative to 16.5mm gauge (below). Several types of railway may be portrayed:
  • Again, small industrial lines serving quarries and all sorts of other undertakings
  • Major feeder lines built to bring raw materials to railhead or port, a very good example being the Ffestiniog Railway in North Wales. These may or may not have provided a passenger service as well.
  • Common carrier lines, where built to the 2ft gauge, serving remote areas and providing all the facilities and services of a main line railway the best known example in the U.K. perhaps being the Lynton & Barnstaple in Devon.


Probably the most commonly used scale/gauge combination. There is plenty of trade support not much that is ready to run or nearly so. Track gauge used is 16.5mm, common with OO/HO so there is a wealth of ready options for mechanisms and running gear. OO/HO track can be adapted or specialist 16.5mm track from PECO used. A wide variety of railways can be reasonably portrayed, having track gauges between 2ft and 2ft 6in. Examples include:
  • Once again, a variety of industrial lines, mostly in the 2ft gauge end of the spectrum
  • Lines using a gauge around 2ft 3in which include the Talyllyn Railway in North Wales, for example
  • 2ft 6in gauge lines, including the Leek & Manifold in Staffordshire or the Welshpool & Llanfair in Mid-Wales.
Note that there are many interesting prototypes using the 3ft gauge in the British Isles, particularly the once-extensive network on the Isle of Man and many lines in the island of Ireland. 16.5mm track gauge really doesn't look right for these in 7mm scale and regrettably there is virtually no trade support for the 'correct' 21mm gauge, although a few keen modellers have gone down that route. There are also a number of modellers who have adopted 5.5mm to 1ft scale in order to use 16.5mm track and mechanisms for 3ft gauge prototypes and they have their own organisation to support their efforts.


Mainly for North American prototypes, using 16.5mm gauge track in the same way as O-16.5 above. The scale used is 1:48 or ¼in to 1 ft. Much more detail may be found on this page.