A container stacking storage system loading trolley that includes a chassis and a container seat that is height-adjustable relative to the chassis. The container seat includes a receiving region with a container contact surface. A lifting device, operable in a lifting direction, is arranged between the chassis and the container seat, and includes a first lifting drive and a second lifting drive. The second lifting drive is configured to act on an unlocking device that is configured to act on holding elements of a container stacking storage system.