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)



On30 Depot


Beware of the bears!

What is On30?

The 7mmNGA encourages narrow gauge railway modelling in all its many forms. One area that has become very popular in recent years is the primarily American On30 scale. The United States has not converted to metric and still uses Imperial measurements. Whereas British O gauge is 7mm:1ft, 1:43.5 scale, the American equivalent is 1/4 ins:1ft, which is the slightly smaller 1:48 scale.  

Model railways are plagued with abbreviations, many of which appear to be contradictory. When one considers the descriptions given to narrow gauge models it gets even more complicated. For example, does O-Gauge use "O" the letter - On30 or "0" the number - 0n30. For consistency (always open to conjecture) the original description from the early days of model railways would have intended "0", as in zero. It is a smaller scale than 1-Gauge (1:32nd scale) and the less well known 2-Gauge and 3-Gauge scales were larger. "HO", or indeed "H0" if we are to take it further, is half O, (or 0), Gauge, being 1:87th scale rather than 1:43.5 scale. In reality, however one writes it the meaning is the same and we have adopted On30 as the most commonly used designation.
 
O gauge has always been popular, both sides of the Atlantic, in standard gauge and various narrow gauges. In the UK, the most popular narrow gauges were around two foot. In North America, three foot narrow gauge was the most popular in overall mileage terms, with large rail networks in Colorado. However, the State of Maine, on the East Coast, is famous for its two foot narrow gauge railroads.  In the early years of American railroading there were many more, built to a surprising variety of gauges, both narrow and broad. As the years progressed many of these lines either failed and were abandoned, or were converted to standard gauge.
 
American model railroaders have traditionally laid their own track, which was useful when modelling 2ft and 3ft gauge prototypes, as until relatively recently little commercial track was available. This meant that narrow gauge modelling was a rather niche market, relying greatly on imported and expensive brass locomotives and rolling stock, plus "craftsman" kits.

On30 as a scale/gauge combination, (sometimes referred to as On2½, particularly in the American magazine Model Railroader), has been around for decades and represents 2ft 6ins (30 ins) gauge. Whilst this gauge was not common in the US, it does enable the use of standard OO/HO 16.5mm track, in the same way as 7mm narrow gauge modellers use this track to represent gauges of around 2ft. Both are a compromise, but the convenience of being able to use a wide variety of commercial track generally outweighs the slight inaccuracies in gauge.
 
On30 was popularised by the American division of Bachmann Industries Inc. in the late 1990s, reputedly financed by the Christmas decoration market, as placing a circle of railroad track around the Christmas tree is popular in the States. Since the introduction of a nicely proportioned 2-6-0 Mogul locomotive and some passenger coaches, they have produced a diverse range of narrow gauge prototype locomotives and rolling stock. These represent prototypes which operated on both 2ft and 3ft narrow gauge railroads, both in the US and elsewhere in the world. Baldwin, for example, exported many locos to Mexico and Central America, where narrow gauge railroads were widespread and 2ft 6ins gauge was more common and Bachmann have acknowledged this with several of their more unusual locomotives.
 
Of particular interest to On30 modellers has been the release of beautifully detailed geared locomotives, featuring the three main types, the Shay, the Climax and the Heisler. This has encouraged the building of layouts with logging and mining as the primary themes.
 
In common with many manufacturers these days, Bachmann produces their models in batches, so not all the range they have produced is available at the same time. However, over the last few years they have produced 4-6-0 tender locos, 2-8-0 Consolidations, both inside and outside framed 2-4-4 Forneys as used in Maine, diminutive 0-4-0 and 0-4-2 Porter saddle tank locos, inside and outside framed versions of typically American 4-4-0 tender locos and two types of Mallet articulated locos. Several were supplied with a selection fuel loads to replicate coal, wood and oil firing.
 
For fans of internal combustion locos, Bachmann produced a small Davenport "gas mechanical" and a rail bus, complete with matching trailer, the prototype for which actually existed on a West Virginian standard gauge shortline, the Buffalo Creek & Gauley. Also prototypically correct is their rail truck, based on the reconstructed Rio Grande Southern "Galloping Goose" Motor Car No.1. More recently they have released a larger centre cab Whitcomb diesel loco. This has a heavy diecast metal body and operates beautifully. 
 
All except the Mogul have been offered with a DCC capability at some point in their production and some have been made available either factory fitted with a sound chip and speaker, or have the internal connections to retro-fit one at additional cost. The Mogul is to be re-launched soon, complete with DCC on-board and a separate sound board which can be retrofitted simply by clipping it in place, for those modellers who like this sound option. For modellers with the original versions there are several how-to articles showing how to retrofit a DCC chip available to read on the Internet. 
 
A wide range of passenger coaches and freight cars are available from Bachmann, Chivers Finelines and several American manufacturers, both as ready to run models and as craftsman-style kits. 
 
The Association is keen to promote this interesting facet of O gauge narrow gauge modelling. Within the On30 Depot we are pleased to show examples of On30 layouts and rolling stock. Check out the Gallery section where albums of photos showing some fine On30 layouts are available for browsing. It is our intention to add to this database of modelling inspiration by reprinting articles and photos of On30 projects that have appeared in past issues of Narrow Lines, that will hopefully encourage you to investigate further this fascinating and rewarding scale/gauge combination.
 
We also offer a constantly changing selection of pre-owned On30 items for sale. The condition of these items can vary enormously, from as-new, mint and boxed, to projects needing some serious care and attention. The full description of each will give the details. Check out the "Rip Track" section if you are looking for a bargain or a challenge. (Rip Track is a common American railroad term meaning "Repair in Place", which seems appropriate).
 
In addition, please check out our New Modelling Goods section (Click here for Modelling Goods ) where you will find a selection of 1:48 scale American O gauge detailing items from Grandt Line. These cover a wide range. You will find windows and doors for scratch building structures, detailing parts for freight cars and passenger coaches, complete interiors for passenger coaches and cabooses (cabeese?), scale switch stands and even tiny mine skips. We also stock a selection of American knuckle couplers from Kadee, scale wood from Mount Albert and scribed plasticard from Evergreen. All detailing parts are available from our stand at the shows we attend and via mail order. If you want to learn more, we have published the On30 Handbook, available from our Publications page for just £7.50.

Not yet a member? Click here to join the leading Association for Narrow Gauge Modellers in the scales around 1/4inch and 7mm to the foot.

Interested in the range of second-hand On30 stock we offer to members? Click here to see what's currently in stock.

MEMBERS: - Please ensure you are logged in to see the prices.
Email orders to the Richard Coney at on30depot@7mmnga.org.uk ensuring that you quote the reference number of the item you want.