Abstract: A machine for transporting tote pans to and from storage compartments arranged longitudinally in vertical rows along an aisle includes a vertically movable carriage provided with a pair of longitudinally spaced, transversely extending tote pan supporting guides which are transversely shiftable between centered and tote pan transfer positions. Associated with the guides is a pair of endless chains, each arranged in a horizontal orbit extending below one of the guides around the sides and ends thereof and carrying a pair of equidistantly spaced pins projecting above the support level of the guide, the pins on one chain being aligned longitudinally with the pins on the other chain. The chains are driven simultaneously in opposite directions on a storage or retrieval cycle synchronously with a cam which shifts the support assembly transversely.