I am gluing down Midwest brand cork roadbed today, and have some doubletracked curves where I could just lay one cork roadbed alongside the other for a distance.
However, is the roadbed made to some official clearance, or what is the “official” clearance number?
The Midwest product gives 1and 7/8" centerline to centerline. This looks like it may be enough, but is it?
In my yards and straight sections I have more like 2 and 1/4 to 2 and a half inches centerline to centerline.
Your last set of numbers are more realistic in HO for curves tighter than about 24", but it depends on the items negotiating the curves, and also whether they’re on the inside or on the outside. My Rivarossi H-8 is truly a monster and it takes up a ton of overhang room on curves that are in the 36" range…it’s something you have to see.
John Armstrong (late) and the NMRA have published guidelines if I recall.
Yes, less than 2" is too tight for almost every class of railroad at 32" radius or less. I will have to move this roadbed apart a bit.
Ah, and now that I read more closely, I see that the Midwest cork roadbed is indeed, made to run edge to edge, and give the correct clearance for all classes of railroad, but only while keeping the sections straight. The NMRA clearance for straight sections of HO is 1 and 13/16 inches separation, while I measured the midwest cork bed at 1 and 7/8 inches separation…or right on NMRA standards for a straight section. Not earth shaking news, and I kind of supposed this would be correct or the manufacturer would be silly to make it otherwise.