{HEAD ~ The single line} in the system is designated with two reference characters 19 a and {TAIL ~ 19 b} to signify which side of the platform the line is connected to 
{ HEAD ~ The single line } in the system is designated with two reference characters 19 a and { TAIL ~ 19 b } to signify which side of the platform the line is connected to
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL REL OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH