BRIDGE NAVIGATIONAL WATCH ALARM SYSTEM (BNWAS)
It is basically a watch alarm system that requests bridge watchkeeping crew to periodically push a button if not an alarm is triggered in the cabin of the Deck officer and the captain.
BNWAS is aiming to detect the inability of the watchkeeping crew on the bridge of the vessel.
The purpose of bridge navigational watch alarm system is to monitor bridge activity and detect operator disability which can lead to Marine accident. The system monitors the awareness of the officer of the watch and automatically alerts the captain or another qualified OOW for any reason the OOW becomes incapable of performing the OOW’S duties.
This purpose is achieved by a series of indications and alarm to alert first the OOW and if he is not responding to the alarm the captain or another qualified OOW, additional the BMWAS may provide the OOW with a mean of calling for immediate assistance if required.
STAGES OF BNWAS
STAGE 1 – when the autopilot is engaged the bridge officer is required to signal his presence to the BMWAS system every 3 to 12 minutes in response to a flashing light either by moving an arm in front of a motion sensor for pressing a confirmation button.
STAGE 2– when a confirmation signal fails to occur within 15 seconds in stage 1 an alarm will sound on the bridge and if there is still no confirmation signal after a further 15 second in the captain’s and the first officer’s cabin one of them must then go to the bridge and cancel the alarm.
STAGE 3 – If neither the captain nor the first officer cancels the alarm within a specified time period between 90 second and 3 minutes depending upon the size of the vessel an alarm sound in location where other personals are available.