S gauge Lionel Model Train Track

S gauge model train track measures .87 inch between running rails. S Scale is a proportion of 1:64, or 3/16 inch to the foot. When A.C. Gilbert converted his entire American Flyer train line from O to S, after WWII, this track - for use with S scale model trains - became hugely popular. S scale was considered by many to be an excellent compromise, falling approximately halfway between O at 1:48 and HO at 1:87.