O Scale versus Proto48 versus what I am doing

Both O scale (1:48) and Proto48 are 1/4” scale. (1 foot equals a 1/4” on the model)

One difference between the two is the distance between the rails of the model. O scale rails model a 5 foot track gauge (1.25 inches when modelled) whereas Proto48 (P:48) models a 4 foot 8.5 inch track gauge. The standard track gauge of North American railroads that I model is 4’ 8.5”. 

Atlas O Scale Wheels (Larger Flange and Wider Tread)

Proto48 Wheels (Prototypical Flange and Tread)

Prototype

A visible difference, between O scale and Proto48 , is the appearance of the wheels. Proto48 wheels appear more prototypical than the O scale wheels (see above pictures). The finer more prototypical Proto48 wheels require different tolerances for track work especially on turnouts.

This model railroad will definitely use the Proto48 wheels. The appearance is closer to the prototype and I am willing to pay the extra for that appearance.

However, there seems to be an association of finer details on Proto48 models, both track and equipment , that will not be pursued on this model railroad. For this reason I labelled the model as O scale with 4’ 8.5” track gauge.