1) Stacker crane
The stacker crane in appearance looks like a conventional bridge crane except that in place of a hoist, a rotating ridged or telescoping mast is suspended from the bridge trolley with the mast equipped with a load handling device such as single or double forks or a grab. These cranes can be manually operated or powered and are used where the carne spans multiple aisles allowing for the storage and retrieval within any aisle of items such as coils of steel.