[sparkycuda]

Concerning how to power tracks from the upper works: there was a center shaft (vertical) that was driven by bevel gears upstairs and ended in bevel gears in the lower works. These drove a horizontal shaft with sprockets on the ends for chain drive to the track sprockets (crane folks called them tumblers) that made the tracks turn. There was a dog-clutch in the horizontal shaft for each side, so to turn, one was disengaged and the other side was driven. The reversing gears were in the upper works where the vertical shaft was driven, again with dog clutches for forward and reverse functions. It was complicated but worked very well - for the "olden" days.
Your model is big enough that it could be done but would take some major repositioning of what you have already built to install. Since you have all the other machinery up there already, it will be easier to put electric motors in the lower works and just make a slip ring for getting the electrons downstairs.
I enjoy seeing your crane - lets me remember how machines worked 50 years ago.

Ken