Looks like they just use simple steel frames to hold the rockets untill launch. Unless it takes a long time to attach the wire or whatever is used to actually launch them, it can't be THAT long.
did the math and a single person could reload this (at least get the rockets into the launchers) in 9 hours if it takes him about 30 seconds to put each rocket into the launch frame, assuming he doesn't have to carry the rockets out. I'd figure at least 10 people working to reload it.