Hi, I don't collect railroad lanterns only barricade lanterns. I know that if the railroad used blue lenses on there lanterns it was used for if they were working on the tracks and they would mount a sign that says men working and the person that put the lantern on the tracks was the only person to remove the lantern after they were done with there project. I read were police departments used blue lenses and green lenses when operating intersections at times to control traffic years ago. I also have a few blue and green globes for the NO.40 traffic gards. Really a nice globe. Steve.