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