Creating simple bridge structure in a recursive script Python for Rhino

Hi Everyone I'm new to the forum and also new to scripting in Rhino, in fact I have only been able create very basic geometry using Python for Rhino.

About my project and what I want to try and achieve,

I would like to try and create a truss system using a recursive function in python for rhino that basically finds the midpoint of any given curve, then draws a vertical line from the mid point, the length of the vertical line is based on a ratio so 1/3 of the length of the given curve, once the vertical line is drawn, it is then connected to the start and end points of the original curve and the steps are repeated until say crv length < 3m. 

It is a little confusing so I have graphically tried to show it in my attached screenshots. I would appreciate any help that I can get.