I have just been watching an old film (1997 crime, thriller) which involved a US railroad passing through snow covered mountainous area.
The Caboose, was fitted with a heavy steel wing on one side, maybe both sides. It was around 15 foot long, hinged against the side, vertical in profile and could be deployed to swing out, and given support by a steel support wire. It seemed to be air or vacuum operated, to deploy it.
Curious - anyone know what it might be for?