BNWAS and Bridge Alarm Test Record

This article applies to yachts with a Bridge Navigational Watch Alarm System, bridge alert panels, central alarm handling, alarm repeats, or integrated bridge systems that present navigational alerts to the bridge team.

Applicability depends on the vessel's flag, class, size, commercial status, bridge equipment fit, SOLAS position, yacht-code route, survey history, and whether bridge alerts are part of type-approved navigation, radio, VDR, or integrated bridge equipment.

From an ETO or bridge technician's point of view, BNWAS is easy to underestimate because it usually looks like a simple timer and reset button. In practice, it is a watchkeeping safety system. If it is bypassed, badly placed, misunderstood, silenced, or not tested properly, it can give everyone false comfort.

BNWAS is not there to prove that a watchkeeper is navigating well. It is there to challenge the bridge watch and escalate if the bridge does not respond.

The basic sequence is simple:

1. The system runs a dormant period while the bridge watch is active.
2. It gives a bridge alert if the watchkeeper does not reset or acknowledge in time.
3. If that is not dealt with, it escalates beyond the bridge.
4. If escalation is still not answered, it should keep moving the alert to the next defined level.

The exact timings and arrangements depend on the approved system and vessel configuration. The test record should therefore capture the installed behaviour, not a generic assumption copied from another yacht.

When I test a BNWAS, I am not only checking that a buzzer sounds. I am checking whether the system is in the correct mode, whether the reset points are sensible, whether the bridge indication is obvious, whether the escalation path actually reaches the right people, and whether anyone has left a bypass or defect in place after service.

BNWAS is one watch alarm function. Bridge Alert Management is a wider discipline for how alerts are prioritised, displayed, acknowledged, transferred, and handled on the bridge.

On older or simpler bridges, the BNWAS may be a separate panel with reset buttons and remote alarm outputs. On newer integrated bridges, alerts may appear through bridge workstations, alarm panels, central alert displays, or manufacturer-specific bridge suites. That makes the test more important, not less.

The bridge team needs to know which alarms are watchkeeping alarms, which are navigation-equipment alerts, and which are repeats from other systems. If everything is treated as "just another bridge alarm", the crew can miss the difference between a nuisance alert and a safety-critical escalation.

Before deliberately letting any alarm escalate, make the bridge team aware and choose a safe moment. Do not run a test in confined waters, during pilotage, during heavy traffic, or while the watch is already managing another abnormal condition.

The pre-test check should confirm:

• test approved by the officer in charge,
• system is not needed for an active watchkeeping risk,
• bridge team understands this is a test,
• engineers or crew receiving remote alarms are warned,
• relevant logbook or test sheet is ready,
• bypass key, password, or mode control is understood,
• previous defects or temporary workarounds have been reviewed.

The best tests are controlled and boring. Everyone knows what is being tested, what should happen, and who will stop the test if it does not behave as expected.

The sequence below is written as an onboard test record, not as a substitute for the manufacturer's manual or the vessel SMS.

1. Identify The System State

Record the make, model, location, active mode, dormant-period setting, reset locations, and any remote alarm outputs. If the system has a key switch, password, service mode, or bridge-mode dependency, record that too.

Do not skip the mode check. A BNWAS left in the wrong mode can pass a superficial panel check and still fail the operational purpose.

2. Confirm Reset And Acknowledgement Points

Walk the bridge and check the reset or acknowledgement points. The bridge team should not have to leave the watch position in an unsafe way just to reset a timer.

At the same time, check for bad habits. A reset button taped down, hidden behind equipment, placed where it can be knocked accidentally, or used as a convenience button during long watches is a warning sign. It may mean the yacht has a human-factors problem, not just an equipment problem.

3. Let The Bridge Alert Trigger

Start the test and allow the first bridge alert to trigger. Record the time, indication, sound, display location, and whether the alert is clear from normal working positions.

If the bridge team cannot tell what the alert means, the test has found something useful. The correction may be labelling, familiarisation, alarm presentation, or a manufacturer setting. Do not simply write "alarm heard" and move on.

4. Confirm Escalation

Allow escalation to the next level only when it is safe and agreed. Confirm where the alarm repeats: captain, officer cabins, crew mess, engineer call system, central alarm panel, or another assigned location.

Record who received it, where they were, what they saw or heard, and how they knew it was BNWAS rather than another alarm. If the alarm only repeats as a generic sounder with no meaning, the bridge team and management should know that.

5. Reset, Restore, And Close Out

After the test, restore the normal operating mode and confirm that no bypass, service mode, inhibited output, or muted alarm remains active.

This final step is where poor test discipline creates risk. A yacht can pass a test and still sail with the wrong mode selected because nobody treated restoration as part of the test.

BNWAS bypass or inhibit functions should be controlled. There are legitimate service and operating reasons why a system may have modes or controls, but a casual bypass is a serious watchkeeping weakness.

The record should show:

• who authorised the bypass,
• why it was needed,
• when it started,
• who knows about it,
• what compensating watchkeeping measure is in place,
• when it will be restored,
• who verified restoration.

If the test uncovers a bypass that nobody owns, treat that as a defect. It is not enough to say "BNWAS was off." The yacht needs to know why it was off, who left it that way, and how the same thing will be prevented.

Most BNWAS faults are not dramatic. They are small weaknesses that reduce confidence in the system.

Typical findings include:

• reset point not working,
• alarm volume too low,
• bridge display unclear,
• escalation not reaching the intended cabin or panel,
• remote alarm labelled poorly,
• dormant period set differently from the bridge team's expectation,
• bypass key left in place,
• crew unfamiliar with the alert sequence,
• alarm history not reviewed after a defect,
• no evidence that the previous test was completed.

The technical fix may be simple. The operational fix is often wider: update the test record, brief the bridge team, correct the SMS checklist, and assign ownership for recurring checks.

Do not close a BNWAS defect just because the panel has stopped alarming. Close it when the watchkeeping function is proven again.

A proper closeout should include:

• fault description,
• immediate control measure,
• service action or adjustment,
• retest result,
• mode restored,
• records updated,
• officer or captain acknowledgement,
• any crew familiarisation required.

If the system is part of statutory bridge equipment for the vessel, involve the appropriate flag, class, surveyor, manufacturer, or approved service provider where the defect or repair route requires it. The article cannot decide that for every yacht, but the test record should make the question visible.

A yacht is preparing for an overnight coastal passage after a yard period. The bridge technician runs a BNWAS test before departure. The bridge alert sounds correctly, but escalation does not reach the captain's cabin. It only appears on a general alarm repeater in the crew area, and the label does not identify it as BNWAS.

The first reaction is to treat it as a wiring or configuration issue. That may be true, but the operational issue is clearer: if the watchkeeper failed to respond at night, the intended escalation path might not wake the person expected to intervene.

The technician records the fault, confirms the system mode, warns the captain, and checks the vessel procedure. The yacht either repairs and retests the escalation before departure or applies an approved temporary measure with extra watchkeeping controls. The important point is that the test created evidence before the passage, not an argument after a near miss.

Use one test record for each formal test, defect retest, annual service support check, or post-refit handover. At minimum, capture:

• Download resource: BNWAS and Bridge Alarm Test Record. URL: /resources/bnwas-and-bridge-alarm-test-record/. Description: Printable test record for BNWAS mode checks, reset points, bridge alert timing, escalation, bypass control, defects, retest, and closeout evidence.