A gantry crane is an overhead crane bridging two legs that move on wheels or sit alongside a track or rail system. Full gantry cranes are used in shipyards or ports and terminals to move ship parts or containers weighing hundreds of tons. United Rentals offers portable gantry cranes that can lift up to 725 pounds and are used for on-location construction, warehouse or HVAC applications. Portable gantry cranes can lift and hold heavy machinery in place while it's being worked on or assembled.