The second clamp 14 opens by removing a primary pin and {TAIL ~ a safety pin} in the nature of {HEAD ~ the first clamp} 
The second clamp 14 opens by removing a primary pin and { TAIL ~ a safety pin } in the nature of { HEAD ~ the first clamp }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD