{HEAD ~ This cab} has front and rear doors and a remote control for operating a motor which drives the chains within both of {TAIL ~ the trollies} simultaneously 
{ HEAD ~ This cab } has front and rear doors and a remote control for operating a motor which drives the chains within both of { TAIL ~ the trollies } simultaneously
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH