{HEAD ~ The insert} 52 is thus compressed within {TAIL ~ the cavity} 50 and against the rail seat area 18 of the tie 12 
is compressed within
{ HEAD ~ The insert } 52 is thus compressed within { TAIL ~ the cavity } 50 and against the rail seat area 18 of the tie 12
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH