Why 5,100?

This big concrete block was just lying around on a sidewalk on Harbor Island. Evidently, it's very important to have a 5,100-pound concrete weight available when one is... uh... doing whatever it is one does on Harbor Island. Maybe it's a counterweight of some kind?

The way I remember it, yesterday's image is a detail of the attachment equipment on the top of this block, but looking at today's picture, I don't see any chains (which are visible in yesterday's shot), so maybe the two images are not of the same object, after all.

By strange coincidence, 5,100 pounds is apparently also the weight of the 10 Commandments display that caused such a ruckus in Alabama a while ago. Maybe this is the replacement that the ACLU suggested? It certainly has nothing to do with religion...