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