During the last 30 years, the trend, some may call it an obsession, with the desire among many baby boomers to have their 3-rail trains as "scale" has been an interesting phenomenon. Many of us grew up with Lionel, American Flyer, and Marx traditional or semi-scale trains, and likely didn't give a hoot about whether our toys were scale. As we got older and had some money 
from working our tails off, we slowly but steadily wanted our trains and structures to be more "scale." This transformation happened to me around 1991 when I saw my friend's Erie Triplex running; it simply looked neater to me. I think this was due in no small way because our 3-rail track systems are a bit wider and much higher than what the proportions of real railroad tracks are to real trains, and "scale" trains tend to diminish this discrepancy.
Yet, it always confused me that O-scale was listed by the manufacturers as 1:48 scale and HO (half of O) as 1:87. If HO was half of O, then HO should've been listed as 1:96 scale. I am sure the TCA has published this discussion before and some of you may already be aware of the origins. Evidently, it all began with Marklin producing the original O-scale trains in 1:43.5 scale. Now the math works, and I can rest 
. BTW: In Europe, 1:43.5 "O-scale" is still the standard.
