Any BNWAS that has been installed prior to July 1, 2011 should preferably be of an approved type that conforms to MSC.128(75). A BNWAS installed post July 1, 2011 is required to be of an approved type that conforms to MSC.128(75).
If a BNWAS was installed before July 1, 2011, but the conformance with MSC.128(75) cannot be documented, such equipment may be exempted from full compliance at the discretion of the Flag Administration (SOLAS Chapter V Reg.19.2.2.4). DNV is authorized to recommend applications for such exemptions when the equipment is in compliance with the rules for the NAUT-OC/-AW/-OSV class notations and/or when the following functionalities are present in the system:
- It is possible to switch the equipment ON and OFF. The selection facility for turning the equipment ON or OFF is to be protected via a key switch or a password or by being installed in the Master’s cabin.
- The equipment remains dormant for between 3 to 12 minutes after being switched on.
- At the end of the dormant period, there is a visual indication as well as an audible alarm in the wheelhouse. It is possible to set the system to display the visual indication only for the first 15 seconds, before sounding off the alarm.
- In the event that the alarm is not resent within 30 seconds in the wheelhouse, an alarm would be sounded in the back-up officer’s and/or the Master’s cabin.
- In case the alarm is not resent within 30 to 90 seconds of the first visual indication, an alarm is sounded in public spaces, such as the mess room, ship’s office and/or conference room. For larger vessels, the period for reset may be extended to 3 minutes. There is an option to combine this alarm with that described in the previous bullet.
- There is the provision of an alarm reset function in the wheelhouse, which could be a push button and/or movement detector.
Electromagnetic Compatibility and Environmental Protection
Before installation, it is important to confirm whether the BNWAS is appropriate for the vessel. This can be done via a test report, a test certificate or a manufacturer’s specification. Alternatively, a declaration of trouble-free operation from the vessel’s manager can also be used.