Booms up, ready to ´go alongside´
The cargo gear has been raised and prepared for discharge and loading of goods. One of each set will be swung out over the pier as the "yard boom",(a hold over term from a time when a block at the end of a sail yardarm would have been used), and the other would be centered over the hatch.
the ´whips´ would be connected together at the cargo hook and the winch operator would lift the cargo with one boom, shift it to the other boom using both winches and lower it with the second boom.