When {HEAD ~ the flatbed unit} is connected to {TAIL ~ the pulley system}, after the fifth wheel has been disengaged, the slabs can be folded together and pivoted into a stored position 
When { HEAD ~ the flatbed unit } is connected to { TAIL ~ the pulley system } , after the fifth wheel has been disengaged , the slabs can be folded together and pivoted into a stored position
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH