Once opened, the second clamp 14 is placed around {TAIL ~ the drill stem} and {HEAD ~ the hinged jaws} are closed 
Once opened , the second clamp 14 is placed around { TAIL ~ the drill stem } and { HEAD ~ the hinged jaws } are closed
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH