A Short History of the Scales

In the Beginning

In the beginning railway models were made to no particular scale.

They were push toys in cast iron or lithographed tin plate.

When small electrical motors became available the first motorized models were made. As the early motors were large, the early models were large.

In around 1892 Marklin created the numbered gauges (#4, #3, #2. #1) and #0 which became O Gauge.

Early motors ran on A/C, in a few short lived early models 'House Voltage!'. This was quickly reduced to a lower safer voltage. This led to the three rail system still used by Lionel, Marklin and others.

O-Scale

O-Scale (1/48) was supplanted by HO-Scale. Currently O-Scale is divided into two camps; Toy- Train which runs on the original three-rail track and Scale which runs on two-rail. You should not be put off by the term Toy-Trains as some beautiful models have been produced in three-rail.
O-Scale is complicated by the fact that there are two O-Scales. O-Gauge runs trains to a scale of 1/48 (1/4" to the foot) on the standard 1.25" track. O-Scale runs the correct 1/43.5 scale models on the 1.25" track. Confused yet?

HO-Scale

Advances in DC motor design (smaller and more powerful) and reductions in house sizes led to a new scale "Half-O" or HO. In England and other places this was Double-O "OO".
With a scale of 1/87.1 or 3.5mm to the foot, HO-Scale is still the most popular scale.

TT-Scale

TT-Scale arrived post WWII. For a while it was the third most popular scale. The arrival of N- Scale pushed it into obscurity. It is still relatively popular in Europe. In North America it is a very fringe scale.

N-Scale

N-Scale (1/160) arrived in the late 60's with ready-to-run products from Arnold-Rapido. It has grown to be the second most popular scale.

Z-Scale

In 1972 Marklin introduced Z-Scale 1/220. Several manufacturers produce Z-Scale models.

T-Scale

In 2007 T-Gauge 1/440 was introduced in Japan.

Gauges

In most of the world Standard Gauge is four feet - eight and a half inches.
Despite the urban myth about the width of two horses asses, the gauge was set by George Stephenson. The last colliery he had worked at used a track gauge of 4' 8". It had worked well there so he used it on the Stockton and Darlington Railway and then the Liverpool and Manchester Railway. From there it grew to be the most popular gauge.
At various times in various locations in the world the track gauge has varied from 2' to 7'. Early Canadian Railways were built to 5'6" gauge. They were later converted to standard gauge. Russia uses five-foot gauge. Much of India is five-foot six inches.
Narrow gauges; two-foot, three-foot and three-foot six inches were used in mining railways, branch line and shortlines where cost was a factor.

For most every prototype gauge, there is a corresponding modelling scale/gauge combination.

For a more in depth look at the history of model trains we recommend the book "150 Years of Train Models" from Carstens Publications.