The Harcourt Street branch line (which was closed in 1958) was used for filming most of the train scenes. By this point, only the single track between Foxrock and Shanganagh junction remained, which was being ripped up at the time filming took place.
Second (and final) film to be directed by actor Nigel Patrick, though he remained a busy and successful stage director.
ITV television transmission: 10th September 1973