Turnout # vs curve radius

[Mike Shrode]

I know there is no such thing as a dumb question. Hopefully not anyway. I've recently joined NMRA and will probably get many of these answers with their standards info. Do the turn-out #'s have a direct relation to curve radius.i.e.. #6 turnout = 24' radius curve? And where would I find these no's Thank You...Mike

 

[grande man]

I know there is no such thing as a dumb question. Hopefully not anyway. I've recently joined NMRA and will probably get many of these answers with their standards info. Do the turn-out #'s have a direct relation to curve radius.i.e.. #6 turnout = 24' radius curve? And where would I find these no's Thank You...Mike

The turnout number has to do with a rate of divergence. Higher numbers have shallow (more prototypical) divergence rates. The diverging route is straight on a standard (not curved) turnout, just like the real thing. "Train set" type turnouts usually have a curved diverging route to work with 18" radius curves and a straight main route. Of course, with curved turnouts, both routes curve. All but the "train set" type are prototypical. That's not much of a technical description, but maybe it will help.

 

[JeffShultz]

There actually is one type of switch that has a curve radius - the Atlas Snap Switch has a curved turnout to match their 18" radius curve track. Beyond that... turnouts diverge but do not curve. The larger the number the shallower the divergence of course.

 

[Little Grande Man]

The turnout number tells you the angle the two tracks of the turnout are from each other. Take any measure, say an inch. On a #6 turnout, there will be a 1:6 ratio. Six inches from the frog, the two tracks of the switch will be 1 inch apart. On a #8 turnout, eight inches from the frog, the two tracks will be an inch apart.