One of SCIH's main sources of revenue from the South Chicago operation was the intra-plant movement of pig iron, loaded slag ladles (to and from the cinder dump), and empty ladles to and from the ladle preparation building.
A significant portion of SCIH's income from the South Chicago area came from the transportation within the plant of pig iron, loaded slag ladles (between the cinder dump) and empty ladles between the ladle preparation facility.