Storage and retrieval system

A storage and retrieval system, comprising:

• at least one mast, said at least one mast adapted to be supported at a lower mast end on a lower rail via at least one running wheel and is adapted to be driven along the running rail by at least one driven running wheel;
• an upper guide rail at an upper mast end, said upper guide rail extending parallel to the running rail having at least one guide roller, said at least one guide roller being mounted such that said at least one guide roller bears against said guide rail so as to guide said mast;
• at least one friction roller, wherein said at least one friction roller rolls on said upper guide rail and bears against said upper guide rail;
• and
• an eddy current brake driven by said friction roller, said at least one friction roller mounted for movement with said upper mast end, said eddy current brake damping oscillations of said upper mast end.