{HEAD ~ The securing} of the plate to {TAIL ~ the underlying structure} causes the pickup arms to release the plate, whereupon they swing upwardly to pick up another plate to continue the process 
to
{ HEAD ~ The securing } of the plate to { TAIL ~ the underlying structure } causes the pickup arms to release the plate , whereupon they swing upwardly to pick up another plate to continue the process
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH