When unloaded, several trolleys of different widths stand on top of each other on a rail system with a slight inclination. A load carrier is placed on the top trolley. The next load carrier pushes the first trolley backwards into the channel at the coloured stop plates, freeing the next trolley. This loading process is repeated until the Pushback Trolley channel is filled. The last load carrier inserted stands directly on the rails. After retrieval, the trolleys run back to the operating side by themselves due to the rail inclination. The excellent running properties of the ball-bearing flanged rollers enable a low rail inclination of only 2.5 %.