The upper level of a pouring conveyor receives sand molds and conveys the empty molds to a pouring station wherein molten material is deposited therein to form castings. Each mold is provided with a supportive weight and jacket before pouring. After the castings have been poured, the molds are transferred to the lower level of the pouring conveyor for cooling purposes, and then back to the upper level to remove the weight and jacket. The sand molds are then transferred to the upper level of a cooling conveyor and are deposited into trays provided on the cooling conveyor. Each tray is adapted to receive a plurality of molds to enable the molds to move from serial to parallel movement. An indexable pusher arm is provided to accurately place each mold in a respective tray to insure proper spacing for uniform cooling. After each tray has traversed the upper and lower levels of the cooling conveyor, the molds are removed from the trays and the sand is broken away to reveal the castings for harvest. The volumetric capacity and cooling time can be adjusted simply by adjusting the number of trays disposed on the cooling conveyor.