Well, i think would be interesting to explain the theory behind this problem:
- RailClone computes an initial vector based on the direction of the first segment of the spline. When this segment is aligned with the Z axis (in local coordinates of the spline), the way to compute it is slightly different, rotating the geometry (really it's not rotated, but aligned with the X local axis).
With closed splines, we can use the "Make first" trick, so the first segment is not Z oriented. But unfortunately, this doesn't work with open splines. You can see the initial vector for each one of the splines in the attached screenshot.
Although it's possible to solve this issue modifying the local axis of the spline, it's a complex and non intuitive procedure. We can use a different workaround here:
1) Create a separated spline with the U shapes.
2) Create a copy of the RC object and assign this spline.
3) Use Generator->X Rotation to rotate the geometry to the desired orientation.
4) If needed, use Alignment parameters to change the position of the Segment.