the arrangement of {TAIL ~ the plurality} of second rotatable means and endless linear means being such that the operation of the first rotatable means causes the simultaneous movement of the opposed side portions of the cover to retractably move the cover over {HEAD ~ the top} of the trailer body 
the arrangement of { TAIL ~ the plurality } of second rotatable means and endless linear means being such that the operation of the first rotatable means causes the simultaneous movement of the opposed side portions of the cover to retractably move the cover over { HEAD ~ the top } of the trailer body
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH