Abstract: A lifting device and method of using the device is disclosed. The device and method may be used to stock a structure such as a high-rise building under construction or an off-shore gas or oil drilling rig. The device in the preferred embodiment contains a pair of booms carried by a pair of boom carriages which are pivoted on a frame attached to the outside of the structure. The booms are capable of moving transversely on the frame and longitudinally within the boom carriages. A trolley and disappearing cargo block are positioned in the booms. Self-climbing features may also be incorporated in the device for stocking several elevations of the structure. The novel device also allows longer cargo to be lifted and turned approximately 90.degree. and moved into the structure. The device may also be installed permanently on the structure and positioned in a non-operative vertical position and pivoted to an operative horizontal position.