BNWAS Bridge Watch Alarm

Simplified Version Bridge Navigational Watch Alarm System – BNWAS

BNWAS Bridge Navigational Watch Alarm System as per IMO MSC 128(75) monitors the officer’s on the watch presence in Wheelhouse under sea going condition.


SELMA Bridge Inspector – Simplified Version is a version of BNWAS developed by SELMA for Light Crafts and small tonnage vessels with basic features:

  • Touch Screen Technology
  • PLC Control Type System
  • Autopilot NMEA 0183 / Dry Contact Auto Mode Activation
  • Heavy Duty Control Panel
  • Separate Alarm Messages
SELMA BNWAS Bridge Watch Alarm System

SELMA Bridge Inspector BNWAS Bridge Navigational Watch Alarm System main objective is to monitor the activity in Wheelhouse and identify any disability of operator which could cause marine accidents.

SELMA BNWAS Bridge Alarm System

In particular BNWAS monitors the awareness of Officer on the Watch (OOW) and automatically alerts the Master or another qualified OOW if for any reason the OOW becomes incapable of performing the OOW’s duties. Consequently a sequence of warning, indications and alarms alert first the OOW and if he is not responding then alert the Master or another qualified OOW.

Additional the BNWAS may provide the OOW with a means of performing Emergency Calling for immediate assistance if it is demanded.

It is important to be noted that the BNWAS should be operational whenever the Ship’s Heading or Track Control System is engaged and generates valid NMEA 0183 Signal according to IEC 61162, unless inhibited by the Master.

SELMA Bridge Inspector BNWAS

For more details please
visit the BNWAS minisite!

Bridge Alarm System combines BNWAS and Bridge Alert Management System concentrating all the alarms from Navigation Instruments in Centralized Touch Screen.

SELMA Bridge Inspector BNWAS Bridge Navigational Watch Alarm System comprises of state-of-the art control and instrumentation technology with maximum performance capabilities, implementing monitoring and alarm function operation.

SELMA Bridge Inspector BNWAS comprises the following equipment:

  • Main Display Unit (Touch Screen)
  • Main PLC Panel
  • UPS/Battery Charger Panel
  • Bridge Remote Reset/Audible and Visual Alarm Stations
  • Officer’s Cabins Remote Alarm/Sounder Stations
  • Public Spaces Sounders
  • Bridge Motion Detectors (Optional)
SELMA Bridge Alarm System Bridge Alert Management System BAMS
SELMA Bridge Alarm System Bridge Alert Management System
SELMA Bridge Alarm System Nautical Alarm System

Bridge Inspector Technical Specifications

Main Display UnitTFT Touch Screen Type
Alternative 1 : Amber Monochrome
Alternative 2 : Colour (65,536 colors)
Main Processor UnitPLC (Programmable Logic Controller)
PLC Digital I/OStandard 36 (max 256)
Operation Modes (Protected)Automatic / Manual On / Manual Off
Auto Mode NMEA Speed4,800 – 38,400 bps
NMEA 0183 Inputs1 – 4 Serial Ports IEC 61162
Auto Mode ActivationGPS/Heading Track Control IEC 61162
Speed Log Pulse Input (200 – 400 pulses)
Digital Free Contact NC / NO
Modbus PLC Ports2
Ethernet PLC Port1 (Optional)
Motion Sensors PortsStandard 2 (Expandable to 12)
Main Power Supply110 – 230V AC 50 / 60Hz
Emergency Power Supply24V DC
SELMA UPS6 Hours independent Emergency Operation
System Configuration SecurityRemovable Key / Password Protected (Master)
Dormant Period (Td)3 -12 min
First Stage Warning IndicationActive after Td
First Stage AlarmTd +15 sec
Second Stage AlarmTd +15 sec +15 sec
Third Stage AlarmTd +15 sec +15 sec +(90-180) sec * or omitted **
Bridge Remote Reset StationsStandard 6 (Expandable)
Watch Alarm, Emergency Call, Reset , Buzzer
Officers Cabin StationStandard 5 (Expandable)
Duty Call Lamp, Test Buzzer, Buzzer Activation
Public Spaces SoundersStandard 2 (Expandable)
Tamper ProtectionSeparate Tamper Alarms Activation Protected
Supplementary PLC OutputsVDR, Ship General Alarm System
Optional NMEA Output $ALR, $AKN for VDR
Type ApprovedIMO MSC.128(75)
IEC60945 / IEC61162 / IEC62616:2010

BNWAS Bridge Alarm System

For more details please
visit the BNWAS minisite