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