{HEAD ~ The dolly assembly} is used to unwind {TAIL ~ the wound strip} of material from the roll and position it on the roof to facilitate its seam welding to an adjacent strip of material 
is used to unwind
{ HEAD ~ The dolly assembly } is used to unwind { TAIL ~ the wound strip } of material from the roll and position it on the roof to facilitate its seam welding to an adjacent strip of material
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL REL TAIL 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