Abstract: A cart loader assembles objects advancing along an infeed conveyor line into arrayed rows of parallel columns, and transfers these arrayed rows of columns to individual shelves of a multi-tiered rolling cart. The cart loader has an external frame enclosing a vertically elongated front elevator and a central staging zone fed by the infeed conveyor. A multi-deck elevator has decks spaced apart vertically by a distance corresponding to the vertical distance between shelves on the multi-tiered cart, latched to the frame for loading. A plurality of horizontally deployable and retractable pushers are each aligned respectively with one shelf, and positioned for delivery of objects from the elevator zone to the cart. A preferred deck-loading and cart-shelf loading sequence achieves minimum loading cycle time coupled with maximum time within each cycle for replacing each loaded cart with an empty cart for the next loading operation.