Standards Gauge....for O3R??

Not to my knowledge.  How can you have a gauge that accommodates both a modern scale steamer and an IVES from 1910?

To have a standards gauge, you have to first have standards, and O3R is too diverse, has too long a history, and has too many variants for a single gauge.

Well, as others have said it varies based on the manufacturer, era, equipment, etc.  The Postwar Lionel service manual specifies different gauges for the 773 Hudson (quite narrow to negotiate O31 curves), and wider for the 2-4-2 locos, presumably so they don't weave from side to side on tangent track.  So there ARE standards established by the manufacturer, and applicable to specific pieces of equipment.

All that being said, if your customer switched to Ross or Atlas track, his derailment problems would probably be over.

The O Gauge Guild over in the UK has standards for what they call Coarse O.  This could be a good start for establishing US standards for Coarse O as well.  http://www.gauge0guild.com/manual/01_1_standards.pdf

They have the O Gauge Guild which only concentrates on O where as our NMRA is more a HO centric organization from my prospective.  Our O Scale Kings Organization could become something like the O Gauge Guild.  But it may be just a cultural difference between us and the Uk that is a reason we don't have this type of scale society organization.  

In the past the North West Shortline Company offered O hi rail wheel sets. I wonder what they used as a standard.

palallin posted:

 

To have a standards gauge, you have to first have standards, and O3R is too diverse, has too long a history, and has too many variants for a single gauge.

That, in a nutshell, is pretty much it. Would be virtually impossible to develop such a gage (spelling it that way to distinguish from our common use of gauge) for 3-rail simply because every type of 3-rail track used would require a gage of its own. And there are no real (meaning firm) standards for other 3-rail items such as wheels, etc.