Normally Deployed Active Barrier Safety System
3.2.1 Initially with no vehicles present in the inbound lanes and the
Inbound Barriers' Manual - Auto - Local mode selector switch in the Auto
mode, Barrier A is open and Barrier B is closed. Incoming vehicles are
checked at the ID Check point and if cleared are allowed to pass over Barrier
A and proceed to the Stop Line for Barrier B. The guard at either the
Gatehouse or the Guard Booth will then activate the Inbound Release switch.
Upon activation of the Inbound Release switch, the Traffic Signal for Barrier
A shall go from Green to Yellow for three seconds and then to Red. After an
additional second of Red, Barrier A's close circuit shall be energized to
close the barrier. After Barrier A is fully closed, Barrier B's open circuit
shall be energized to open Barrier B. When Barrier B is fully open, its
Traffic Signal shall change from Red to Green to allow the vehicle or
vehicles to proceed onto the Installation.
3.2.2 When the vehicle or vehicles between Barriers A and B have passed over
Barrier B, the guard will activate the Inbound Fill switch. Upon activation
of the Inbound Fill switch, the Traffic Signal for Barrier B shall change
from Green to Yellow for 3 seconds and then to Red. After an additional 1
second at Red, Barrier B's close circuit will be energized to close Barrier
B. After Barrier B is fully closed, the open circuit for Barrier A shall be
energized to open Barrier A. After Barrier A is fully open, its Traffic
Signal shall change from Red to Green.
3.2.3 The same controls apply to Barriers C and D in the outbound lanes and
control switches Outbound Release and Outbound Fill.
3.2.4 The close circuit for all barriers shall be supervised by the Vehicle
Presence Detectors (VPD's) in front of and behind the barrier, such that if
either VPD detects a vehicle, the barrier close circuit shall be suppressed.
3.2.5 A red indicating light adjacent to each Fill switch shall light when
the lane barriers are in the Fill position, i.e., the initial barrier is open
and the final barrier is closed. Similarly, a red indicating light adjacent
to each Release switch shall light when the lane barriers are in the Release
position, i.e., the initial barrier is closed and the final barrier is open.
The Fill and Release indicator lights shall only light when the barriers'
mode switch is in the Auto position.
3.3 MANUAL MODE OF OPERATION. When the Inbound Barriers Manual - Auto -
Local mode switch is placed in the Manual mode, the inbound barriers shall be
controlled from the individual barrier Open and Close switches on the Master
Control Panel. Initiation of a Close command to an open barrier shall cause
that barrier's Traffic Signal to change from Green to Yellow for 3 seconds
and then to Red. After an additional one second of Red, the barrier's close
circuit shall be energized through the VPD's immediately in front of and
behind the barrier. If the VPD's are clear, the barrier shall close.
Initiation of an Open commend to a closed barrier shall energize the open
circuit for the barrier and open the barrier. After the barrier is fully
open, the Traffic Signal shall change from Red to Green. In the Manual mode,
both initial and final barriers in a given entrapment area can be opened.
Situations requiring this configuration include passing a vehicle that is
longer than the entrapment area. In such situations, guards must provide
compensatory security measures to defeat a threat while both barriers are
3.4 LOCAL MODE OF OPERATION. When the barrier's Manual - Auto - Local mode
switch is placed in the Local position and the barrier is open, the Traffic
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