Container covering apparatus

The apparatus (2) includes two side arm units (4) each having a lower arm (8) having a top end pivotable coupled to the base end of an upper arm (10). Sprockets, which wind an endless chain, are installed at the ends of each lower arm. A spool (16), which supports a roll of cover (15), extends between the tips of the upper arms. An independent claim is also included for a truck container top opening covering method.