Ok, here is the link to an image. Anyone know much about this? http://karakullake.blogspot.com/2017/10/1955-narrow-gauge-electric-police-train.html
Google-Fu: It's a 2ft wide, 240V 3HP "catwalk car" with 3 settings: Off, 6mph and 12mph used in the Holland Tunnel and runs 2200 feet. Started in 1954/55 and apparently in use up until 2011. Here's another version of it:
I know I want the Packard Clipper, though I'm not sure if it's a '53 or a '54. That and it's not a train, it's a tram.
I've seen one of those in a manufacturing plant for the management and inspection crews. It seemed to be of about that age but, no cops. Well not official cops.
It's been years since I've been through there, but IIRC there were booths periodically where one could take a break in fresh(?) air. I guess cameras have eliminated the need for them. I never saw them as rail related.