Patent ID: 8408863

Claim:
A method for handling conventional cargo containers within a hold of a vessel wherein the hold includes a plurality of vertically oriented multi-tiered cells in which the cargo containers are selectively stowed one upon another, and wherein the method includes the steps of: A. providing a grid track system above the cells of the hold and in spaced relationship with respect to the cells so as to define an open space between an upper tier of the cells and the grid track system and wherein the track system includes pairs of spaced and parallel overhead tracks which intersect with one another in an X-Y plan; B. providing at least one transfer unit which is moveable along and support on pairs of tracks of the grid track system in an X-Y direction with respect to a horizontal plane and wherein the at least one transfer unit includes hoists; C. selectively positioning the at least one transfer unit over one of the cells within the hold; D. Connecting the hoists to an upper cargo container within a vertically aligned cell and elevating the connected cargo container into the open space adjacent the grid track system; E. Moving the connected cargo container above an open area or to an open tier within a different cell, and thereafter lowering the connected cargo container to rest within the open area or different cell and disconnecting the hoists from the connected cargo container and moving the at least one transfer unit from above the open area or different cell; and thereafter F. elevating the disconnected cargo container from the open area or different cell and off-loading the disconnected cargo container from the hull of the vessel.