Materials and design of a spring rider/platform. (Undergraduate Project, Assistance needed)

In design 100 at the moment creating a handicap accessible spring rider. My teammates and I are struggling to find specifications on materials used to produce the piece of playground equipment. We have called a few companies to try and figure out what materials they use, but they have only went to voicemail.

I don’t know if anyone on this sub will have any advice, but any is appreciated.