The rearward section can be moved longitudinally to adjustably locate {HEAD ~ its rearward edge} in a selected position forward of {TAIL ~ the trailers} wheel assembly 
The rearward section can be moved longitudinally to adjustably locate { HEAD ~ its rearward edge } in a selected position forward of { TAIL ~ the trailers } wheel assembly
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH