The backfill sleeve 126 is approximately the same width as {HEAD ~ the trench} 114 which provides for {TAIL ~ consistent filling} of the trench 
provides for
The backfill sleeve 126 is approximately the same width as { HEAD ~ the trench } 114 which provides for { TAIL ~ consistent filling } of the trench
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH