Model Memories and Image Replicas are the only vendors I know that make HO 3rd rail. Does anybody out there knows of any other vendors? There are two types of 3rd rail in the prototype world; the under the 3rd rail shoe and over the 3rd rail shoe. That means when the 3rd rail shoe of the electric multiple unit railcars touch under or over the 3rd rail. I noticed that the PATCO system is colored white on top in the elevated segments of the line. I want that for my model train layout.