Set/put in train
Origin of set/put in train?
The basic meaning of noun "train" is "to drag": ence "train" as the trailing back of a long skirt, or a row of cars pulled by an engine, and a whole slew of other meanings. In a figurative sense it could mean a course or order of persons, things, ideas ("train of thought")
or events. From here it was a short step to taking on (in the early 16th century) the sense "Proper sequence, order, or arrangement for some result; connected order; course, process". Thus things could be in good train, or be set or put in train. (VSD)