In #105, the pre-collapse close up of the pier and truss structure, are the “pins” those horizontal rolling-pin looking objects with "gears" or sprockets on the ends? It appears that the teeth on the gears engage other teeth on the base. I wonder what the function of these is? Do the gears actually rotate with stresses or expansion/contraction? Or are the gears static and originally used for tightening? It is difficult for me to imagine how the forces are handled. Obviously, I have never looked closely at such a structure before.
RE: My previous comment #132:
From reading the other thread I am inferring that those pins are part of the “rocker bearing” and are supposed to move (rotate). Kind of amazing. Anyone can clarify this?