The transfer chamber is sized so that {HEAD ~ a workpiece} may pass between {TAIL ~ the chambers} 
pass between
The transfer chamber is sized so that { HEAD ~ a workpiece } may pass between { TAIL ~ the chambers }
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL