(a) a plurality of inverted U-shaped support bows to extend laterally across the trailer, each side of each support bow having a downwardly extending arm terminating in an end;

(b) means associated with each support bow to secure thereto peripheral portions of tarpaulin sections for covering the trailer;

(c) roller means secured to each end of each support bow for sliding movement on a different one of a corresponding rail mounted on a corresponding side of the flatbed trailer;

(d) a plurality of pairs of inverted U-shaped uplifting bows having central portions to extend laterally across the trailer and arms downwardly extending from ends of the central portions, each pair of uplifting bows pivotally secured to lower portions of the arms of each support bow on opposite sides, to spread apart during opening of the tarpaulin system and support the tarpaulin sections from beneath when the system is open, and to close to a position near the corresponding support bows when the system is closed;

(e) an intermediate support rod secured to each adjacent pair of uplifting bows secured to adjacent support bows, the intermediate support rods to extend laterally across the trailer between the uplifting bows beneath the tarpaulin sections, said intermediate support rods being secured to said uplifting bows so as to maintain the intermediate support rods at about the height of the support and uplifting bows when the tarpaulin system is open and raise it above that height to restrict the tarpaulin sections from falling between the uplifting bows when the tarpaulin system is closed.