Any extra slack can therefore be maintained also within {TAIL ~ the center portion} 138 of {HEAD ~ the raceway} 118 
Any extra slack can therefore be maintained also within { TAIL ~ the center portion } 138 of { HEAD ~ the raceway } 118
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH