It is difficult to create coupler height standards for narrow gauge cars as each railroad seemed to have their own. Look at the latest issue of the GazetteIt shows a B&SR two foot gauge flat car and the coupler height is 16 inches. This lower than Colorado or EBT equipment. So if you built a model of this car to scale you'd have a problem coupling it to something like a DRGW 3000 series boxcar.
It seems that Bachmann has set a de facto standard for On30 when they decided to use HO couplers and standards.
As for operating On30 there is no reason not to use the NMRA standards for On3.
It seems that Bachmann has set a de facto standard for On30 when they decided to use HO couplers and standards.
As for operating On30 there is no reason not to use the NMRA standards for On3.