O Gauge Model Train Track
Proportions of O gauge model train track are not correct, particularly length. The reason for this is scale-length rolling stock needs a wider turning radius. Since model trains must operate in small spaces, it is required to reduce their size.
This reduction must be done with the flair of an artist to retain the illusion of correct proportions. Even though the model trains might not be in scale, they should appear to be. This is particularly important with locomotives. With the exception of the Hudsons, most Lionel engines have been shrunk considerably. Still, they all operate on the same O gauge track, and they appear correct doing it.
Found in two basic profiles, regular O gauge and O-27, the tinplate track is commonly and at least five different curvatures.
With a circle diameter of 31 inches, regular O gauge Lionel track has a railhead height of 11/16 inch . The 72 inch diameter O-72 has the same profile, but with a wider radius.
Track of the second profile, known as O-27, is formed from a light steel and has a railhead height of 7/16 inch. A circle has a 27 inch diameter. Two wider radius versions of this model train track are also available from Lionel, O-42 and O-54.
Though they weren't designed to be mixed, they can be used together on the same layout, however, if the O-27 track is shimmed by 1/4 inch and the holes in the tubular rails are enlarged to accept regular O gauge pins.
Almost all O gauge equipment, with the exception of the biggest locomotives and passenger cars, will operate without trouble on O-27 track. Also, except for the Lionel four-wheel-drive steamers made before 1948 and some early Marx units, most O-27 trains will work on regular O gauge track.
O27 trains will run without trouble on O track, but longer O locomotives and cars can struggle on the tighter curves of O27 track, coming to a stop or derailing.
Currently the are other independent producers of model railroading track in O gauge tinplate. However, their profiles are still reflective of the Lionel model train sets.