Have you ever wondered what the different scales of model trains meant and why they are not universal? Much of the issue of scale first came about when modelers began to demand a sort of standard method of producing trains that properly depicted the full size ones that they represented. When the first set of official scales became available they still were not rigidly adhered to and often the wheel size and gauge of the track did not follow scale at all. An example of the is the 0 gauge scale. In the United States it is on a track that is actually too wide for its supposed 1:48 scale. In Britain however it follows a much more rigid standard by following the 7mm/1ft scale which is also much more accurate.

00 standards in Britain are set up on on track that is almost a full seven inches too narrow. This sort of inconsistency with the track differences is still perpetuated by the manufactures who continue to produce model trains whose tracks are bigger than they should be, incorrectly sized wheel treads, and overly deep wheel flanges. It seems that many manufacturers afford gauge and scale the same connotation but this is very inaccurate. Correctly defined, scale is the relative measurement of an object when produced as a properly sized proportion of the original. Gauge, however, just means the overall measurement between the rails on a model railway.

As modelers became more concerned with these inaccurate means of determining the scale of their model trains they developed a finescale set of standards with which they could better determine the true scale of their models. While in use by many hardcore model builders these standards have not been adopted by the mainstream model train industry. Much of the reasons for this lie in the need for manufacturers to be able to produced a cost efficient model that can easily be used by home modelers and expert builders as well. One example of this finescale standard comes from Britain. The P4 standard takes real train track measurements and scales them down to match the model that is to be placed on those scaled tracks. They also make sure that the wing and check rails are scaled just as closely.

The biggest determining factor of the scale of a model train is the size of the engine being used. The largest ridable steam engines can go up to a full twenty eight inches tall which is considered a 1:8 scale. The smallest is 1:220 which is called Z scale and cover matchbox sized locomotives. There are five scales that are the most popular; N scale, TT scale, H0 scale, O scale, Gauge I, and G scale. G scale is the most common for outdoor models at a 1:8 scale and Gauge I may also be used as well. N, 0, and H0 are all very popular indoor scales with 0 being primarily used as children's toys.

Now that you know a bit more about the scale system that is used for determining a model trains size now you are ready to start building your own scaled version!