Calculating Tie Lengths
in a Complex Wye Switch

In a Wye, both routes diverge in opposite directions. As the routes separate, the ties need to get longer to accomodate both tracks until they are far enough apart to have their own ties.

Sometimes one route is straight for some distance beyond the points, but begins to diverge while ties are still common between the two routes. This is a "Complex Wye".

Sometimes the turning radius of both routes are the same. Other times they are different. In this model, all ties are parallel. This program calculates the lengths of the ties needed to complete a Complex Wye switch. It will also calculate the frog angle and number based on track gauge.

Explanation of Input Boxes

Note: All dimensional units must be the same. Inches, meters, etc. Radius of First Branch and Radius of Last Branch The first branch begins diverging immediately at the points, but the second branch continues straight and then begins diverging in the opposite direction a fixed distance from the points. There are two boxes for the radius of each branch. One box for the measured curve radius and one for an optional multiplier which can be used for unit conversion (such as feet to inches). If not needed, the multiplier should be set to 1. Distance to Second Branch The Distance to the Second Branch is measured from the points. Normal Tie Length The length of a normal track tie. Switch ties will progressively get longer. Tie Spacing The measurement from tie to tie, not the gap between them. It is the center to center distance. The width of ties is not needed. Snap to Nearest Unit This allows you to select how much precision you need. The tie length will be rounded to the nearest unit you select here. Track Gauge This is only needed if you are using the optional frog angle and number calculator. Enter the actual gauge-face dimension. The frog angle will be calculated in degrees. The frog number is 1/2 the cotangent of 1/2 the frog angle. Both frog angle and number are rounded to .25.

Complex Wye Switch Tie Length and Frog Calculator

 x Radius of First Branch
 x Radius of Last Branch
  Distance to Second Branch
  Normal Tie Length
  Tie Spacing
  Snap to nearest unit
  Track Gauge

  Frog Angle
  Frog Number

(select box to solve)
Tie Lengths Needed and Tie End Distances from centerline