This shift of compression load allows the load on {HEAD ~ the compression drivers} on {TAIL ~ both cycles} to be balanced 
This shift of compression load allows the load on { HEAD ~ the compression drivers } on { TAIL ~ both cycles } to be balanced
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH