I looked through the CRB and Ultimate Combat and could not find out how much siege engines weigh, in particular the standard catapult and the gatebreaker ballista.
I think this is going to come up in the next session I run and was wondering if the community had any thoughts.
I was thinking at least a tonne for the catapult and probably about 3 times that for the gatebreaker ballista.
This page has D&D weight figures for some kinds of siege engines. Should be good enough for Pathfinder.
Thanks, Fuzzy-wuzzy. That is perfect. It gives me a baseline to work from.