These bumpers and other types are mostly used at the end of any siding or stub end track to prevent a car or loco from going off the end. That said, most locos under speed would easily crash right through these bumpers because of their mass and weight. You may also have seen concrete bumpers, stacked wood ties and even just a big pile of dirt at the end of stub tracks.
As far as the Atlas bumpers that you have, these are the older type that they produced. The give-away is that the track is brass as opposed to the nickel-silver that is commonly used today. Also the ties appear to be fiberboard instead of plastic that is used today. I do not believe that what you have can be illumunated. Some of them can. Check for a small hole in the bumper body that goes totally through from top to bottom. The pictures do not show one however. A grain of wheat bulb, usually red in color, should fit in there and can be powered from the track itself or an outside source.
