matching cars to industries

[Russ Bellinis]

Don't they have a car flipper oper thingy for emptying the cars that are full of gravel coal and stuff like that?

Only with hoppers, I believe and only at a facility that takes multiple train loads of cars like a power plant or coal dock for train to ship transfer. Most gravel operations would either use a bottom dump from a hopper onto a conveyor system in a pit, or would use a front loader riding on top of the side of a gondola. Rotary car dumpers are expensive and require special rotary couplers or uncoupling each car individually to dump. It is much more efficient to do a bottom dump with a standard hopper for less than train load shipments.