Are the HUB workers that load/unload the trailers and sort the volume employees of FedEx or workers for a super contractor?
And if they are workers for FedEx how come i've never heard of anyone unionizing them?
The handlers for Ground are employees of Ground, and not "contractors".
As to their not being unionized. I'm going to be straight with you...
The turnover among handlers is so high, that it isn't worth the effort for a union to engage in unionizing them. Handlers don't do that job as a "career", it is a stepping stone to something else. Express handlers last between 4 and 6 months on average, and they're out the door. They're worked hard, treated with very little respect, and shoved out the door as quickly as possible to keep labor costs low. A few last 2-3 years, but do so either because they work the AM and need the insurance (and waive minimums), or work the PM and are students that need a fixed dependable schedule. There are workers in the SEIU that make about the same or less than handlers, but they do the work as a career, thus making unionization sensible.
For Express handlers, they are covered under the RLA, meaning that they'd have to have 50%+1 vote to certify on a nationwide basis. Given the high turnover rate, even if 65% voted to certify, by the time the union got around to seeking certification after a vote, at least a third, maybe half that voted to certify would've already quit.
I'm sure the turnover among Ground handlers is even worse than Express handlers. Ground handlers are paid a couple of bucks an hour less, and their benefits aren't quite as good as Express benefits. For the part-time handlers at Express, the benefits (considering they're part-time and entry level) are decent. For the full-time career employee (and part-time Couriers that have been around for a few years), Express benefits leave a bitter aftertaste, that just never seems to go away (every time I see a brown truck, I curse FedEx).