Diameter of N scale track.

Model Railroader General Discussion (Model Railroader)
1

I would like to know what the diameter is on the 18" radius curved track for N scale.

2

The diameter is twice the radius. 36".

3

So this means that the diameter is the same for both N and HO. (or all scales)

4

The radius is usually measured to the center of the track, and so yes, 18" radius is the same on all scales, and the diameter is the same on all scales. The distance from the center of curvature to the OUTSIDE of the track with the same radius will differ from scale to scale.

5

Because the diameter is measured in real inches, not scale inches, yes, they are the same. You can buy sectional track in a variety of radiuses and the diameter is always twice the radius. When buying a trainset, the radius is often 18" (36" diameter) with HO and 9 3/4" (19 1/2" diameter) with N scale. 18" radius is small for HO and large for N.