Lionel super o track radius question.

I do know they came as O-36.  Were there any O-72's?

No. Only 0-36.

Super "O" track was introduced in 1957. Switches were "tweaked" in 1958. Lionel started a long, dismal downhill slide at that time, and no further changes were made to Super "O" track.

Super "O" had some nice features. Insulated sections were available in straight and curves. Small, unobtrusive lockons fit neatly into a slot in the center rail. Outer rail lockons were clamped on. A pair of control "blades" fit into holes in the ties. ANY staright section could be an operating track. One blade was wired to a transformer; the other, to an outer rail. A small magnet fit just about anywhere an uncoupler was needed.

Super "O" curves can be bent to a wider radius. I have heard that Super "O" switches have "issues." They are non-derailing but not as rugged as 022 switches.

I prefer Lionel FasTrack to Super "O": much wider selection of straight sections, curves and switches. Switches work well.

Super "O" is good for a branch line or part of a layout. I think FasTrack has a lot more to offer.

Re-curving Super O may be possible but not easy. All the sleepers are connected under the outer rails. Re-curving 027 or O would be a snap in comparison. I hate the look of modern plastic roadbed track, unless well detailed, its louder, and more fragile than the softer S.O., but it is easier to come by and has more, and better options. 

I have a question, does 0-27 mean that the center rails are 27 inches apart in a semi circle, or where does the 0-27 come from. 

Mike Spanier sells regular curves only but he can provide a link to several guys who make and sell wide-radius Super O curves.  Or you can go to the Super O Yahoo group which Mike moderates where you can get plenty of info on Super O.  The guys that make the custom curves and Super O Bob are members of that group.  Here is the link:

http://groups.yahoo.com/group/Lionel_SuperO_Track/

HTH,

Bill   

Madison:

27” is the approximate OVERALL diameter of a circle of “O27” track measured from the outside edges of the ties.  The center rail-to-center rail diameter is only 24½”.

HTH,

Bill