... by the frame,which can be design to be multi-floor(typically 2 layers),with staircase. The multi-tier racking is ... warehouse area.It could be designed as single or multiple mezzanine,generally 2-3 layers,according to the actual field and ... per layer.The general ways of transportation from 2nd floor to 3rd floor are:manual,elevating table,hoisting machine,conveyor belt,and ...