The walkway is parallel to {HEAD ~ the lift beams} and is secured to {TAIL ~ the cross beams} 
The walkway is parallel to { HEAD ~ the lift beams } and is secured to { TAIL ~ the cross beams }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL