Karamba - Catenary Curve with Steel Tube Section


Fairly new to grasshopper here - I’ve been messing around with Karamba lately and was wondering if anyone could show me how I may start to model accurately a catenary curve made of steel tube sections similar to the project in the images in the link below by rcr. I’ve been able to create a similar section with the deformation, but how can I get an accurate depiction of the bending of a steel tube supported on the end points based on length and type of steel tube? See link for clarification.

Any help is much appreciated, thanks.