These are all real sizes used.. although I can't really see any purpose for the "T" gauge, or "Z" gauge, except maybe used in a big city plan for investors. N gauge is generally used by those who like big landscapes and want to recreate that with long trains going through them. "TT" is not popular in the USA for example, but very popular with central European hobbysts. H0 (properly pronounced H-Zero) is the most popular gauge and one representing the most variety. Larger gauges are more specialized, as they are easier to model almost every detail. S gauge was very popular in the States after the war, it's been making a comeback lately with very nicely detailed equipment available. "0" gauge, and here i have to digress; Americans are known to butcher stuff and they are commonly pronouncing this size as "O" (oh), it is actually properly a 0 (zero) gauge. This size actually varries depending on the continent which is modeled in. In the States common scale is 1:48, in Continental Europe more common scale is 1:45, in Great Britain 1:43,5 scale is used for the rolling stock, and all of these are running on track measuring 32mm between ther rails. Here in the States there is also so called "Proto 48" which would be considered as "fine scale" with thin wheels just like on real cars and locomotives. "1" gauge (1:32 scale) is reffered to as "King gauge", because one can quite literally build even every nut and bolt on a model that size. "1" gauge trains ride on track measuring 45mm between the rails...and here we come to another example of Americans butchering stuff again; the so called "G" gauge originally represented European Narrow gauge equipment in about 1:24 scale as developed by LGB and running on 45mm track. In the States firms like Aristocraft started to produce so called "G" gauge standard size equipment running on "G" gauge track; 45mm, but a narrow gauge style track. In effect there is now a lot of available equipment in about 1:29 scale, but really not proportional exactly, that runs on the so called "G" gauge track. Those caricatures of locomoives and cars are actually popular with the outdoor garden railroad modelers, but keep in mind, these are not to scale. Only 1:32 scaled stuff running on 45mm track keeps the proper scale (for standard gauge) and this equipment is on the more expensive side; Märklin, KISS, Hubner and few others specialize in these models. Lately MTH started coming out with properly scaled 1:32 size locomotives, their SD70ACU is a recent example.
www.tgauge.us
. That J-3a "Hudson" (there were about 10 like that) was the main locomotive for New York Central flagship train the "20th Century Limited"; one of the most famous American luxury trains.
