For this reason, {TAIL ~ each guide device} on the bidirectional guide system of the invention exists in {HEAD ~ two states}: a director state when in the rigid configuration and a follower state when in the floating configuration; it adopts these states alternately depending upon the vehicles direction of travel 
For this reason , { TAIL ~ each guide device } on the bidirectional guide system of the invention exists in { HEAD ~ two states } : a director state when in the rigid configuration and a follower state when in the floating configuration ; it adopts these states alternately depending upon the vehicles direction of travel
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH 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 OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH