This is just my understanding; have worked at UPS for slightly longer (six to seven months now) than you have. My understanding
is incomplete; bear that in mind.
Those PTsupes report to some FT supe?
Generally, yeah. In operations, for example, the PT supes report to a FT manager (the shift supervisor), who himself generally is subordinate to the Center Manager.
I'm guessing that the shift manager would be it then
but what does that dude even do?
I can only speak for my Shift supervisor; I have read on this forum that it is often very different (as illustrated below).
When I arrive in the morning, he is sitting in his office banging away on the computer doing add/cuts and trying to create a plan whereby he can "fit" all the packages that need to be delivered into the routes (or drivers, if you will) available to him (see footnote #1). This is why, for example (you may or may not be familiar with this aspect of the operation), supervisors who print out route manifest sheets too early often have problems because the sheets do not accurately reflect the add/cuts the shift supervisor made.
Other duties I have noticed include acting as a stand-in PT supervisor when one fails to arrive on time, or I have even seen mine come up and help me split the belt when things are
really bad ... we talk about drinking and beer, to take our (for different reasons, I'm sure) minds off of the task at hand.
Also, I have seen my Shift supe get reamed from the New York office ("the call") because our center failed to meet production, ridiculous amount of misloads, etc. In summation, the Shift Supervisor should (I stress that word, as I have read that things vary) be the one who is responsible for the entire shift, which is the aggregate production of the PT sup's and hourlies under him.
and what do feeders do/what are they?
Feeders, as I understand them, are the longboxes/pups that are loaded/unloaded by hourlies. Feeder drivers then haul these around to other hubs/centers.
Footnote #1: I've read that the routes available to a center manager/Shift sup is handed down from on high (regional/district managers), and so they are fighting a losing battle. I certainly cannot speak to this as I have no experience with it; browse around the forums and you can read posts offering various points of view.
edit: Although, also note that their are FT Driver sup's who PT sup's occasionally report to/deal with, because it is their (the driver sup's) responsibility to handle the drivers, while it is the PT sup's responsibility to make sure the trucks are loaded and ready to go by 8:30am or whatever it is in your area; I've noticed there is some considerable overlap in this area. Regardless, it demonstrates the fact that there are overlapping areas of responsibility, and this is probably not limited to Operations. Again, I know very little about this sort of thing, just what I've observed.
I would like to add that I think your username, ToastyMittens, is awesome. I hope you stick around; I won't feel so lonely for not knowing how UPS works.