I was checking out manhole covers on my way to work and noticed one abbreviation (“DWS”) that I later searched for online. Here’s a handy Wikipedia page on manhole cover abbreviations in NYC, and some of them link to pages about the companies or public works divisions they refer to. But some covers only indicate which ironworks made them.

Two of them are rather intriguing:

• BPB = Borough President Brooklyn
• BPM = Borough President Manhattan

Would these be leading to dedicated ducts for the respective BP’s offices? And if so, are they   access points for internet, cable, or something else? Vacuum tubes? Escape tunnels?

The Wiki page includes links to a couple of other useful sites – including Forgotten New York (an excellent source for all kinds of info on old NYC infrastructure, streets, buildings, and their vestigial traces.)

There’s also this website, with great photos.