The arrangement of the support pulleys and endless cable is such that by operation of the winder pulley , the cover is retractably moved over {HEAD ~ the top} of {TAIL ~ the trailer body}  
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The arrangement of the support pulleys and endless cable is such that by operation of the winder pulley , the cover is retractably moved over { HEAD ~ the top } of { TAIL ~ the trailer body }
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 REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH