K-Bridge BNWAS

Common issues

• Reset button/switch wear or failure to register operator presence
• False alarms from sensor misconfiguration or vibration-sensitive detection
• Backup alarm relay to the public address/crew alarm not tested and found non-functional
• Firmware requiring update after bridge integration changes
• Wiring or connector corrosion at bridge wing repeater panels
• Battery backup failure for the alarm unit

Inspection checklist

• Test the full alarm sequence timing (first stage, second stage bridge, third stage crew/master alarm) against SOLAS-required intervals
• Verify all reset points, including bridge wing repeaters if fitted, function correctly
• Check indication and dimming of lamps on the control unit
• Test the backup power supply and confirm the alarm still functions on battery
• Verify the alarm escalates correctly to the crew alarm/PA system
• Check the event log/recording function if fitted
• Confirm any interface with autopilot/steering operates correctly where linked

Service intervals

Critical spares

• Reset switch/button unit
• Backup battery pack
• Control unit fuse set
• Bridge wing repeater unit, if fitted

Safety

• BNWAS is a statutory safety system - never disable or permanently mute the crew alarm stage
• Verify alarm audibility actually reaches crew accommodation before accepting the installation as compliant
• Do not treat a silenced or acknowledged alarm as a substitute for an actual bridge watchkeeper being present and alert

Class survey

BNWAS is a SOLAS V/19 requirement checked at annual and renewal surveys; the surveyor will normally require a live demonstration of the full alarm sequence including the final crew/master alarm stage, so keep test records and any dispensation paperwork on board.