Before there was double stack and TOFC, there was simply piggyback. Case in point is this eastbound Canadian Pacific extra freight (note the white flags) at Dorval, PQ, headed for Montreal with a block of piggyback on the head end. Judging from the variety of trailers there were few limitations on what type of equipment CP would accept in those days.
Hauling the freight are two notable Alco (Montreal Locomotive Works) diesels, an RS18 trailed by an FA.
Canadian PacificFuture TPOTD