HO Parallel Track Spacing

[Anonymous]

What is the recommended track spacing for HO Main lines?

[cwclark]

I believe it is safe to go with 2" center to center on straight track and 21/2" in the curves...Chuck

[Big_Boy_4005]

For HO 2-3/16" for an 18" radius curve. Centers can get closer as radius increases. Straight track is 1-13/16". The complete table can be found at this link, be sure to read all of the notes.

http://www.nmra.org/standards/s-8tables.html

[Anonymous]

did you see that the recommendation for full size passenger cars are a min. of 32 radius. and 2.5" spacing . WOW , I thought 26 was supposed to be o.k. !

[dknelson]

a lot of people use 2" but that is wide by prototype standards -- and the prototype also usually keeps the spacing even on curves while modelers with sharp radius curves have to cheat. But remember, as Tony Koester has pointed out, that we also have to get our big fat fingers between cars and the prototype does not have to worry about that.

Because my layout features a double track mainline, I did an experiment last year to see how my full length passenger cars would fare on parallel curves if I used 2 inch spacing. I had some spare plywood and crappy old brass flex track that i got at a swap meet for cheap. So I constructed a series of 6 curves using 2 inch centers and tested my full length passenger cars on adjacent tracks. And what I found was that for me, 38" radius and 40 inch radius seemed the safest combination, although I think it could go lower with some risk depending on the overhang of a particular car or locomotive. So to be safe my final decision was to go with 42 inch and 40 inch radius curve double track mainline (and no I do not use brass track on the layout - that was solely for scientific experimenting).
Dave Nelson