Track Spacing & 18"radius (Nscale)

[Adelie]

The NMRA standards page (http://www.nmra.org/standards/s-8tables.html) calls out 1-13/32" for 17" radius given the type of equipment you are talking about. My guess, based on the added inch of radius, is that 1-3/8" would be safe. The best way is to test it out to see whether or not 1.25" gives you enough clearance.

My mainline curves are all 27" but I do have a helix that uses an 18.5" radius to a staging area. It is single track so I don't really have any way to figure out whether or not my passenger cars would sideswipe anything on the way down. I've never noticed any serious overhang when the passenger cars go down the thing, but I can't say I've paid that much attention. I'm modeling the late 1950's, so passenger cars are pretty much the longest thing the Bunter Ridge sees.

[WHartman]

Can anyone offer an appropriate double track spacing for minimum 18" radius curves and modern equipment (autoracks and passenger equipment) in N-scale". I am considering 1.25" center to center. Any problems forseen?
Thanks.