Monday, 13 December 2010

ClassNK Give Clarification on BNWAS Installation

Japanese classification society ClassNK has released technical information to help clarify the criteria vessels under its class should meet with regards to the installation of bridge navigational watch alarm systems (BNWAS).

The requirements for a BNWAS were laid down in amendments to SOLAS Chapter V Regulation 19 and the performance criteria for these BNWAS were outlined in MSC.128(75) – Performance Standards for a Bridge Navigational Watch Alarm System (BNWAS). Most of things covered in NKK’s guidelines are the same as in the MSC.128(75) performance standards, however, NKK have given extra detail on a couple of areas to make the requirements more explicit.

The first area of clarification is given in section (1) (ii). Whereas MSC.128(75) only says that the reset function should be easily accessible from the bridge wings, the NKK guidelines explicitly state that one reset device should be provided on each bridge wing unless it is easy to reset a first stage alarm using a nearby reset device in the wheelhouse.

The other area where NKK go into more details is in section (2)(ii). MSC.128(75) only describes the location for 2nd and 3rd stage alarms as ‘locations of the Master, officers and further crew members capable of taking corrective action’. NKK give much clearer guidance by saying the 2nd stage alarms should be located in the Captain’s bedroom and Deck officer’s cabin while the 3rd stage alarm should be located in the Officer’s Mess room, Saloon, Recreation room and Ship’s office.

Even if your vessels are not classified with NKK, you may still find these guidelines useful in providing insight to how one classification society views an area of the performance standards that it feels needs extra clarification.

The full text of the guidelines is as follows:

Guidelines for BNWAS Installation

(1) Reset devices:
(i) At least one reset device should be provided near each conning position in the wheelhouse.
More reset devices may be provided to the workstations for navigation, manoeuvring and monitoring in order for safe and effective operation, if desired.
A reset function may be initiated by motion sensors and navigational equipment such as radar, auto-pilot, ECDIS, INS, etc.
(ii) One reset device should be provided to each bridge wing.
Where it is easy to reset a first stage alarm by a reset device located nearby in the wheelhouse, reset devices are not required to be fitted at bridge wings.

(2) Visual indicators and First stage audible alarms
(i) A visual indicator and first stage audible alarm are to be provided in the wheelhouse.
When they are combined with a reset device, individual visual indicators and first stage alarms are not required.
(ii) A visual indicator and first stage audible alarm are to be provided in the bridge wings.
Where a reset device is not provided in the case of 1(ii) above, the following functions are required:
- Flashing indicator in the wheelhouse should be visible from an operational position on the bridge wing; and
- First audible alarm in the wheelhouse should be audible from an operational position on the bridge wing.

(3) Second stage audible alarms and Third stage audible alarms
(i) Second stage audible alarms should be located in the Captain's bedroom and Deck officer's cabins.
In cases where there are three deck officers on board, one deck officer for duty may be selected from the main panel and the alarm in the Captain's bedroom may be changed to a third stage one.
(ii) Third stage alarms should be located in the Officer's Mess room, Saloon, Recreation room and Ship's office.

(4) BNWAS should be supplied by both an AC source (Main and Emergency source) and a DC source (ship's batteries or batteries contained within the device).

(5) BNWAS for ships constructed on or after 1 July 2011 are to be connected with the following mandatory equipment required by SOLAS.
(i) Heading Control System and Track Control System
(ii) Voyage Data Recorder (VDR)

(6) With respect to small ships, BNWAS installations may be designed according to relaxed requirements in cases where such requirements are specified by the Flag State.

(7) An emergency call facility may be provided.

Navgard™ - Martek Marine’s Type Approved BNWAS

Navgard™ is Martek Marine’s answer to compliance with the BNWAS requirements. It is Type Approved with a number of the major classification societies as well as meeting with MSC.128(75) and IEC 62616:2010 performance standards.

Navgard™ BNWAS – Click to find out more.

1 comment:

  1. Please clarify that reset should not be installed at the chart room, where often an officer is hiding but has limited look out.


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