Containers are respectively loaded onto and delivered from two trolleys of a single crane at pick-up and delivery locations by guided travel along a fixed travel path on a boom between the delivery location at one end of the boom and a central structure of the crane with a platform positioned thereon having a pair of parallel spaced track paths. Lateral movement of the platform alternatively aligns one of the parallel track paths with the fixed travel path to accommodate transfer of the trolleys along such fixed travel path and either one of the track paths on the platform between the pick-up and delivery locations.