{HEAD ~ The common shaft} 138 runs adjacent to {TAIL ~ the front wall} 30 of the trailer 20 
runs adjacent to
{ HEAD ~ The common shaft } 138 runs adjacent to { TAIL ~ the front wall } 30 of the trailer 20
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH