Note that the carriage can move past {TAIL ~ the support members} 19 to a position at {HEAD ~ the left hand end} of the beam 
Note that the carriage can move past { TAIL ~ the support members } 19 to a position at { HEAD ~ the left hand end } of the beam
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH