OO Gauge

As promised, I will now take a look at some of the more common model railway gauges that are available and I make no apologies for beginning with OO Gauge since that is the gauge of layout that we are building. It is also the most popular gauge amongst model railway enthusiasts, at least here in the UK. 

OO Gauge refers to those models that are built to a scale of 4 mm to 1 foot (or 1:76) and, because of this, it has become more commonly known as 4 mm. 

Now to the anomaly that I referred to in my earlier posting entitled "Scales and Gauges". This concerns the gauge of the track in that, at 1:76 scale, the track should be 18.83 mm gauge whereas, in fact, it is 16.5 mm. The reason for this goes back to the 1920s when a 4 mm scale system was introduced by the German company Gebrüder Bing and which ran on on 16.5 mm gauge track. However, this did not prove very popular and it was a short time later that manufacturers began building models at Half O Gauge or HO at a scale of 3.5 mm to 1 ft running on track that was 16.5 mm gauge. This was then used by British manufacturers who continued to use 4 mm to 1 ft for their models, mainly because it was easier to fit the electronic motors of the time into the slightly larger models.  

The introduction by Meccano in 1938 of Hornby Dublo, a range which became popular virtually straight away, helped establish OO Gauge as the dominant size in the UK. However, with the same gauge of track being used for OO and HO, it does mean that trains of both scales can run on the same track. 

During the second half of the Twentieth Century manufacturers such as Tri-ang, Hornby, Lima and Bachmann all produced a massive and comprehensive range of models and equipment and this has just got better and better during the first decade of the Twenty-First Century with more manufacturers, such as Heljan, adding to the variety of models available. Due to its popularity, OO Gauge modelling also has a plethora of kit and accessory manufacturers offering a wide range of items made from a variety of materials from plastic to cardboard to white metal.  

Standardization between manufacturers also means that models and equipment are all compatible and can be used together. Couplings have stayed more or less the same since Tri-ang invented the tension lock system although the design has been updated in recent years. All HO / OO gauge track is also compatible and the standard rigid or set track is easy to fit together and to lay. However, it must be said that some of the flexi-track can be a bit fiddly to use for the less experienced modellers. 

As far as space requirements are concerned, large layouts in OO Gauge do indeed require a considerable amount of space. A typical 10-coach train, for instance, measures around 10 foot or about 3 m and, ideally, need curve radius of at least 0.60 m. So, a large layout would need to be housed in a loft, attic or large shed. Layouts that feature branch lines or goods yards, and which feature shorter trains, can be accommodated around the walls of a bedroom or smaller shed or, even, as a fold-away layout.