A reference numeral 9 denotes {HEAD ~ a maintenance bay route} for maintenance of {TAIL ~ guided vehicles} 10 
A reference numeral 9 denotes { HEAD ~ a maintenance bay route } for maintenance of { TAIL ~ guided vehicles } 10
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH