Brockville, Ontario had a special appeal for observing VIA Rail operations in eastern Canada. Besides being one of the closest points on the VIA system to my home in eastern Pennsylvania, Brockville was a point of operational interest. Several times every day, westbound trains from Ottawa and Montreal would arrive within a few minutes of each other, and would be combined for the trip to Toronto. Of course, the reverse would occur for eastbound movements, and there were other Montreal – Toronto trains, most notably the Rapido service, that simply made a station stop at Brockville.
The moves to combine the trains varied, but the usual procedure as I recall was for the locomotives of the Ottawa train, seen here on the left, to leave their cars about where they are in the photo, and pull further down the CP branch either to a short spur behind the station, or go farther to be turned on the wye for the reverse trip, if necessary. Meanwhile, the Montreal train would pull clear of the switch connecting the CP branch to the CN main, back onto the Ottawa cars, pull forward, and make the station stop with the combined train.
The presence of the CN SW1200RS indicates a different pattern on this particular day. The Ottawa train typically had one or two FPA4’s, but this one has an FP9B in addition to a pair of MLW cabs. If I recall correctly, the SW1200RS pulled the heavier-than-normal power consist from Ottawa onto the CN main, and with a few more moves, it pulled the combined train to Toronto, and the FPA4/RS18 set were left on the CP.