Oh jeez, why don't you cry about it. Button masks and other paper respirators are generally referred to as "tittie masks" in the industry, because they resemble the cup of a bra. If it really offended you, remove yourself from the intArweb.
PS -- you just said it twice.
PPS -- My point was that I hope he's being safe. Asbestosis, Mesothelioma, throat and lung cancer are no laughing matter.
You will find all kinds of rigging in power plants. There is always some sort of work being done. Looking at the length of the chain attached, I'd say that it's hooked up to a hoistup on a higher elevation on the boiler where there was maintenance being done. It could have been used to bring up toolboxes, planks for scaffolding, piping, beams, welding machines etc. Probably not necessarily for a single piece of equipment.
About the lights being on -- Plants don't directly use the power they generate to operate... itself. They're all tied into a "grid." Suppose one of the plants comes offline for maintenance, they still need electricity to perform whatever maintenance, and to get back up and running. They use power from the grid just like your house, or anywhere else does.
No way to be sure unless I was there, but 17 is probably the elevation above sea level. In most of the plants, instead of the floors going 1, 2, 3, 4, 5 etc. They will go 19, 31, 51, 61, 81, 100.
Apparently, you've never been in a powerhouse. :D I work in all the power plants on Long Island (Northport, Port Jeff, Island Park, Glenwood and Far Rockaway) and I can tell you that they are FAR from clean. They are kept "looking clean" but they're absolutely full of asbestos and many other harmful substances (mostly insulations). You won't see it much on the turbine deck (That's what it's usually referred to as, never heard it called a "hall" ) but once you get up on the boiler itself, it's a different world.
I sincerely hope you wear a good quality respirator with 2091 or 2097 (hepa) filters for protection. Usually colored pink or marked by a pink band. Regular dust masks (tittie masks) will NOT protect you at all from asbestos fibres in the air. And even though you don't see it, it's there. It's the stuff you CAN'T see that will kill you.
PS -- you just said it twice.
PPS -- My point was that I hope he's being safe. Asbestosis, Mesothelioma, throat and lung cancer are no laughing matter.