I WOULD LIKE TO KNOW IF THERE IS A STANDARD DISTANCE FOR PARALLEL TRACK IN HO SCALE. AS IN IS THERE A STANDARD FOR TRACK CENTERS? THANKS
Check the NMRA website for recommended practices. For North American prototype layouts the spacing I have typically seen is 2". This would be a little smaller if you were modelling a European prototype.
Try Chapter 5 of the Track Planning for Realistic Operation by John Armstrong book. It has an excellent discussion of operating standards, track centers, grade, easements, etc. You should be able to find it at a hobby shop or online at Kalmbach. Good luck.
Even though there is a set standard for track spacing, you have to consider how tight your curves are going to be. Some of the longer rolling stock and locomotives, i.e. auto racks, full size passenger cars, and Big Boys will side swipe equipment on adjacent track on 18" radius curves center spaced at 2". You might consider tacking your track down where you want it and then hand rolling your longest cars or locos through the curves to check the clearance.
Ken, D&J Railroad, Stafford, VA
Tony Koester made an excellent point about this in Model Railroad Planning a year or two ago. Scale distance between rails would often be so close that we could not get fingers between cars and we would need huge curves to avoid sideswipes (Ken’s point, above).
For tight curves and large equipment you may have to go to 2 1/2 inch centers
What I did was buy some super cheap used brass flex track at a swap meet, got a piece of scrap plywood, and laid my proposed curves (40 and 38 inch) with 2 inch centers. Then I placed my 80 foot passenger cars and auto rack cars to see if I had side swipe problems. So far so good although I do not rule out that there might be some cars that create problems with 2 inch spacing, and I have since decided to go with 42 and 40 inch curves (this is in HO).
The problem is that 2 inch spacing looks OK on curves but looks absurdly too far apart on straight track. I am building a bridge that had four parallel tracks on it: double track mainline and sidings on either side. I measured the prototype and was shocked to see how much wider it has to be to accommodate 2 inch track centers for all four tracks!
Dave Nelson