You may find https://www.apta.com/mc/rail/previous/20...PWhite.pdf to be interesting reading. It's about the TTC's wiring upgrade from the legacy 'trolley pole' system to the new 'trolley + panto' system...
Edit to add: And http://www.apta.com/mc/rail/previous/201...0White.pdf is about the system I wish we were installing.
Edit to add: And http://www.apta.com/mc/rail/previous/201...0White.pdf is about the system I wish we were installing.
...K