what is the largest(longest) turnout that i can buy? does #6 = a 22" radius curve? i am interested in a minimum 24" curve in a turnout, is this possible? how many of you make your own? where do you purchase rail stock?
thanks
The kinds of turnouts that correspond to curve radii aren’t prototypical and are usually associated with train sets and beginner layouts; the diverging leg of a turnout technically HAS no radius, because it is straight. The curved ones are intended as a drop-in for a train-set loop curve track section.
The big ones, like #6 and #8, as your post mentions, should be of the straight-leg variety, so that doesn’t matter. You lay it, and then make a short transition easement into your curve.
I believe I have seen #8’s in the hobby shop, but then, again, I’m handlaying and haven’t paid a lot of attention. You get the ties, spikes, and rail at the hobby shop, too. (The good ones, not the we-carry-RC-cars-and-model-planes-too kind.)
The bit about turnouts with curves isn’t necessarily true–interurban and trolley lines used single-point turnouts with curved diverging tracks. The Peco “Setrack” brand of turnout is an adequate compromise, but Richard Orr single-point trolley turnouts are designed for a 6" radius curve!
#8’s are out there, but #6 turnouts are plenty wide enough for the biggest model railroad engines.
The #8 is the longest standard turnout available. Remember that numbered turnouts diverge straight. The formula is: number of units distance down the straight leg for 1 unit of divergance. So, for a #6 turnout, 6" down the straight leg, the diverging leg is 1" away. The Atlas snap switch is actually an 18" radius curve, and the #4 is not as sharp.
#10 in Walthers Shinora code 83 is the largest complete turnout I know of. BK Enterprises goes up to #16; you have to spike it to the ties, but can be had assembled. I think Peco makes turnouts with a curve in them. NMRA’s RP on curvature for different equipment includes turnout size - http://www.nmra.org/standards/rp-11.html While it doesn’t cover every radius, it shows several.
Enjoy
Paul