Because the TH&B was in such close proximity to the U.S., many cars destined for other parts of Canada could be seen on TH&B trackage. A TH&B train coming from Buffalo could have more than half of its cars from various American railroads, but when split up for delivery to their final destinations, might comprise only 2 or 3 cars of the entire train. I always felt that one of the bonuses of train-watching in Hamilton was that the train was usually as interesting as the locomotives. Hamilton was a major manufacturing centre, and parts and raw materials came from all over North America.
As for locomotives, in addition to those that I noted in a previous post, the TH&B employed locos of its own plus those of its owners, NYC and CPR. Originally, a train from Buffalo would run, with NYC locos, to Welland, where a TH&B loco would take over, and the train would then be taken, using a CPR loco, from Hamilton to Toronto. It didn't take too long for all three roads to decide that a pool of locos from all three roads would make more sense, and that the originating loco could make the entire trip without change.
Wayne