BNWAS
PURPOSE OF BNWAS
The purpose of a bridge navigational watch alarm system is to monitor bridge activity and detect operator disability which could lead to marine accidents. The system monitors awareness of the Officer of the Watch (OOW) and automatically alerts the Master or another qualified person if, for any reason, the OOW becomes incapable of performing OOW duties.
This purpose is achieved by series of indications and alarm to alert first the OOW and, if he is not responding, then to alert Master or another qualified person.
OPERATIONAL MODES
The BNWAS should incorporate the following operational modes:
– Automatic (Automatically brought into operation whenever the ship.s heading
or track control system is activated and inhibited when this system is not activated)
– Manual ON (In operation constantly)
– Manual OFF (Does not operate under any circumstances)
SEQUENCE OF INDICATIONS AND ALARMS
Once operational, the alarm system should remain dormant for a period of between 3 and 12 min (Td).
At the end of this dormant period, the alarm system should initiate a visual indication on the bridge.
If not reset, the BNWAS should additionally sound a first stage audible alarm on the bridge 15 s after the visual indication is initiated.
If not reset, the BNWAS should additionally sound a second stage remote audible alarm in the back-up officer’s and/or Master’s location 15 s after the first stage audible alarm is initiated.
If not reset, the BNWAS should additionally sound a third stage remote audible alarm at the locations of further crew members capable of taking corrective actions 90 s after the second stage remote audible alarm is initiated.
Ref: Marine Teacher Website