The Great Northern S2s were regular haulage power on this prestigious train and the video shows the G1 Aster spirit fired version hauling a superb rake of J&M Empire Builder coaches. There was presumably an engine change on this long route and there is a second S2 waiting in the picture to take the train forward.
https://www.youtube.com/watch?v=N5hkkndxmA4
https://www.youtube.com/watch?v=N5hkkndxmA4