Abstract: A dust control system to prevent the escape of dust from a cargo hold during bulk materials cargo handling operations wherein a plurality of rigid frames are suspended in parallel configuration across the hold. Unloading equipment is inserted through the frames and the frames are freely traversable between opposite sides of the hold while tarpaulins disposed on either side of the frames expand or accordion as the frames' positions are shifted in order maintain coverage from side to side. Fixed tarps cover the rest of the hold. Curtains extending downwardly from the frames and from those tarpaulins affixed to the frames engage the fixed tarps in an abutting relation to form a seal.