. "These devices may in particular be a chipping hammer (used to break the alumina layer and the solidified bath that usually covers the anodes 3), a crust shovel (used to clear the position of anode 3 after the spent anode has been withdrawn by removal of the solid materials located at this position), a grab for handling the anodes 3 (used to grip and manipulate the anodes 3 by their rod 4 for remov" . . .