The present invention relates to a mobile aggregate processing plant for screening aggregate material comprising a mobile chassis having a main frame and a vibrating screening unit mounted via one or more absorbers on a screen-mounting frame and able to provide at least one aggregate discharge stream therethrough, wherein the vibrating screening unit is moveable relative to the screen-mounting frame between a first in-use position, and at least a second position able to provide an access portal below the vibrating screening unit when not in use.