Finally, this arrangement facilitates maintenance operations, as {HEAD ~ a service engineer} can visually monitor {TAIL ~ the elevator car} or the shaft itself from the drive system 
visually monitor
Finally , this arrangement facilitates maintenance operations , as { HEAD ~ a service engineer } can visually monitor { TAIL ~ the elevator car } or the shaft itself from the drive system
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH