at least one of a spacing between the windings and an angle of slope between the windings and a pipeline longitudinal axis varies along {HEAD ~ the pipeline longitudinal axis} to change the winding density along the pipeline longitudinal axis as a function of local mechanical load requirements of {TAIL ~ the pipeline} 
at least one of a spacing between the windings and an angle of slope between the windings and a pipeline longitudinal axis varies along { HEAD ~ the pipeline longitudinal axis } to change the winding density along the pipeline longitudinal axis as a function of local mechanical load requirements of { TAIL ~ the pipeline }
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 HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL