Calculating angle of curvature relative to the vertical?

This needed a new thread seeing as I need something slightly different, I currently have a curve graph that measures the curvature in 3D. I would like to know the angle of curvature relative to the vertical at several points along the model. How could this be done?

This is so that I can deconstruct the horizontal and vertical forces acting on a (theoretical) train traversing a track, I am currently only interested in the vertical forces acting on the track and train.

Also here is the location of the points in question (58.3 KB) (49.3 KB)