I have just found an interesting video that raised a couple of questions:
https://youtu.be/Ja5VHVU4IKQ?t=352
1. What is the purpose of these "passenger" cars with "a lot of windows"? And why were all the windows removed? Or were the cars without windows originally?
2. What is the purpose of a flashing beacon on the roof of a pushing locomotive? Priority in traffic?

Regards,
Alex