I Capture the Castle (film) - Wikipedia

1hr 57mins
Dir: Tim Fywell
Starring: Romola Garai and Bill Nighy

A teenage girl and her eccentric family survive in a castle in the 1930s

Based on the 1948 novel of the same title by Dodie Smith this romantic drama includes a lot of location work on the Isle of Man. Some scenes were filmed on the 3’ gauge Isle of Man Railway at Port St Mary station with Dübs & Co. 0-6-0T No.15 Caledonia on a rake of period stock. The loco is identifiable by the non-prototypical blue livery it carries.

Port St. Mary station on the Isle of Man and Caledonia has just arrived with a train
Passengers come and go in a moment of frantic activity
In this odd shot from the station yard, Caledonia can be seen through the fence