BNWAS Watch Alarm System

The purpose of the Mega-Guard Bridge Navigational Watch Alarm System (BNWAS) is to monitor bridge activity and detect operator disability

Features

The purpose of the Mega-Guard Bridge Navigational Watch Alarm System (BNWAS) is to monitor bridge activity and detect operator disability which could lead to marine accidents. The BNWAS monitors the awareness of the officer on the bridge and automatically alerts an on duty officer in case the officer on the bridge becomes incapable of performing his duties. In case the officer on duty does not respond, the other officers and other crew members are alerted by the BNWAS.

The Mega-Guard BNWAS also includes an officer on duty selection and an officer call function. The BNWAS is operational whenever the ship’s heading or track control system is engaged. The Master is allowed to disable the BNWAS and this function is protected by entering a personal code.

A NMEA-0183 serial output is available for connection to the VDR. The Mega-Guard BNWAS is powered by two 19~32VDC power supplies: one main supply and one back-up supply.

The Mega-Guard BNWAS fulfills all applicable rules including: IMO MSC. 128(75), IEC62616 and Type Approval by class societies.

System lay-out

The Mega-Guard BNWAS consists of the following items:

• BNWAS Installed in bridge console for flush panel mounting.
• Reset and Audible Alarm Installed on bridge.
• PIR motion detector Installed on bridge for bulkhead mounting.
• Audible Alarm Installed on bridge, officer’s cabins and other crew areas.

Mode selection

Four different modes are available (indicated by LED):

• Watch On
• Watch Auto On
• Watch Stand-by
• Watch Off

The officer on bridge can select with the Mode select switch in between Watch On mode and Watch Auto On mode. In Watch On mode the BNWAS is always active and in Watch Auto On mode the BNWAS is active when the ship’s heading or track control system is engaged. The BNWAS is in Watch Stand-by mode when the ship’s heading or track control is disengaged; the BNWAS is not active in this case. The Master can turn of the BNWAS by selecting the Watch Off mode after entering of a personal code via the Arrow Left and Arrow Right pushbuttons.

Visual and audible alarm

Normal operation

The BNWAS contains a watch timer which can be adjusted in between 3 and 12 minutes. The set-time is displayed on the LCD display of the BNWAS. The BNWAS is downcounting, starting from the set-time, and the remaining time is also displayed on the LCD display. The officer on the bridge has to reset the watch timer before the timer reaches zero; this way he shows his awareness. The reset of the timer can be done in two ways: by pressing the Reset pushbutton or by showing activity so that a PIR motion detector is activated. The BNWAS contains an illuminated Reset pushbutton and in bridges with large work area, additional illuminated Reset pushbuttons have to be installed.

Visual and audible alarm on bridge

In case the timer reaches zero, the BNWAS first warns the officer on the bridge via a Visual Alarm LED. If the officer on the bridge does not reset the BNWAS within 15 seconds, the audible alarm on the bridge is activated as well. For this function, an alarm buzzer is built-in the BNWAS. In addition, external bridge audible alarms which are connected to the Mega-Guard BNWAS are activated. The Mega-Guard BNWAS indicates this mode via the Bridge Alarm LED. In this manner the officer on the bridge is alerted and he can press the Reset pushbutton and reset the watch timer before the on duty officer alarm is activated.

On duty officer alarm in cabin

If the officer on the bridge does not reset the BNWAS within 15 seconds after the audible alarm on bridge is activated, the officer alarm is activated as well. The audible alarm in the cabin of the selected on duty officer will be activated. The Mega-Guard BNWAS indicates this mode via the Officer Alarm LED. In this manner the on duty officer can go to the bridge and overview the situation and press the Reset pushbutton to cancel all alarms and to reset the watch timer before the crew alarm is activated.

Crew alarm

If the on duty officer does not reset the BNWAS within 60-180 seconds (adjustable during installation) after the audible alarm in the on duty officer’s cabin is activated, the audible alarm in all other officer cabins and a crew audible alarm is activated as well. The Mega-Guard BNWAS indicates this mode via the Crew Alarm LED. In this manner an officer or other crew member can go to the bridge and overview the situation and press the

Reset pushbutton to cancel all alarms and to reset the watch timer.

Emergency call

An Emergency Call pushbutton is integrated in the Mega-Guard BNWAS. When pressing this button for 2 seconds, the audible alarm in the on duty officer cabin is activated. The Mega-Guard BNWAS indicates this mode via the Officers Alarm LED and the Emergency Call pushbutton is illuminated. This mode can be reset by pressing the Reset pushbutton for more than 2 seconds. If the Emergency Call mode is not reset within 60-180 seconds (adjustable during installation) after the audible alarm in the on duty officer’s cabin is activated, the audible alarm in all other officer cabins and a crew audible alarm is activated as well. The Mega-Guard BNWAS indicates this mode via the Crew Alarm LED.