The barrel hitch gets its name from its intended use, lifting barrels on to ships. The barrel hitch works by forming a sling around the object and supports the object from two sides and the bottom.
When you have completed step two of the pictorial, place your object on top of the diagonal strand of rope in the center of the knot. Slowly pull the rope up at the working and fixed ends. This will form a sling around the object. Next tie the working end off while making sure the sling is tight around the object. This step is not shown.
Pictoral How To Tie A Barrel Hitch