Switch Radius Questions

[3030RICK]

WHAT ARE THE RADII OIF A #4 SWITCH AND A #6 SWITCH? i HAVE A SPACE ON MY LAYOUT THAT CALLS FOR SOME PRETTY CLOSE TRACKAGE IN A SIDING SITUATION. MOST OF MY ROLLING EQUIPMENT WILL TOLERATE SMALL SWITCHES EXCEPT ONE ENGINE WHICH REQUIRES A MINIMUM 42 RADIUS. I AM IN O GAUGE.
THANKS FOR ANY HELP

 

[Selector]

I model in HO, so I won't be of much use to you. However, if you know the manufacturer, find their site and inquire...they probably have descriptions.

If your scale is anything like it is in HO, you can't count on a standardized configuration for what any one of them calls a "#6" turnout. Some are snap switches and have a true radius, while others are N. American railway standard with straight routes through and beyond the frog...so those type would have what is known as a substitution radius. The substitution radius is as much as three times what the curvature is on the curved points rails for N. American type turnouts.

So, if you do not yet have them, find sellers, or the manufacturer, and see if they post that type of information on their sites...many do.

I hope you get an answer from someone who knows, in the meantime.

 

[UP2CSX]

A switch radius just means that the diverging track will travel one unit of radius for every "X" unit of straight track. A #4 switch, for example will will have a diverging track that leaves the straight track one inch for every four inches of straight, or tangent track. The problem is that not all switches have the same length of tangent track so a #4 for one manufacturer's switch won't be the same as #4 for another brand of switch. The best thing to do is determine exactly what brand of switch you are going to use and either ask the company or get the measurements and calculate the resulting diverging radius. The formula is Frog Angle = arctan ( 1 / Frog Number ). If you post the type of switch here, someone may already have this information.

BTW, typing in ALL CAPS is considered the internet form of shouting and is hard to read.