I work in a plant filled with cranes ... and none of them are DC. Frequency drives and AC motors, every one.
Ditto for the "open" bussbars with some manner of moving contact. Only the 'cross' trolleys use cables in a flexible raceway; the main 'bridges' travel on 1/4-mile long rails; that's a bit long for any form of cable.
I've never looked at the connections between the bussbars and the feeders; let me see what I can find. As luck would have it, we're hanging some new ones this month.
