Isn't scale and gauge the same thing? No absolutely not!

Gauge is the distance between the rails.

"standard" gauge for most of the world and all american railroads is 4' 8 1/2"

"narrow "gauge was used extensively in mountain railroading. Narrow gauge usually refers to 36 inch track, although 30 inch, 24 inch, 18 inch, and even 16 inch were used in special applications.

"broad" gauge on the other hand refers to a distance between the rails greater than 4' 8 1/2". These were specialized railroads used short distances for very oversized cargo, or used in soft swampy areas to spread the load.

Scale refers to the ratio of the model to the original.


Z scale =1:220 1.4mm=1' 24' of track=1 mile

N scale =1:160 1.9mm=1' 33' of track=1 mile

HO scale=1:87 3.5mm=1' 60'7.5" of track=1 mile (Half O scale, ie "HO")

S scale =1:64 3/16"=1' 82'6" of track=1 mile

O scale =1:48 1/4"=1' 110' of track=1 mile

G scale =1:22.5 12.5mm=1' 234'8" of track=1 mile (G scale is kinda tricky. All the trains run on gauge one track but the factories can't agree on a scale)

The 30 miles from Alamogordo to Cloudcroft would require an HO scale layout over 1800' long.

That's why modelers have to use "selective compression".