Tinplate Tom posted:A lot of Lionel pre war stuff, like the 671 and 2020 turbine locomotives were actually built to 3/16th of an inch to the foot but run on O gauge track. Selective compression at its best.
While maybe selective compression at it's best, (and Lionel continues to be the master of it) the 671 and 2020's aren't 3/16ths scale. Not a single one has ever been converted to S scale because they're way to big.
Selective compression has no "scale" as such, because different ratio's are used for length, width and height.
Rusty