This is desirable as frequently {HEAD ~ the opposed sides} of {TAIL ~ the tractor} will deflect in opposite directions 
This is desirable as frequently { HEAD ~ the opposed sides } of { TAIL ~ the tractor } will deflect in opposite directions
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH