What the riding public should never see! The two circular metal mechanisms in the foreground are the door operator sheaves which open and close the car doors. They are controlled by the blue box immediately above and behind the sheave assemblies. To the left of the blue box is the door operator motor. The railing around the outer perimeter of the car top is a safety railing to prevent accidental falls. The blue rail running perpendicular to the safety railing is the cross-head, which is a part of the sling assembly, within which the cab is installed. Mounted on the cross head, from left to right, is a car-top inspection run box, the hoist cables, and a light assembly.