BNWAS Facts

Why install a BNWAS?

The purpose of a bridge navigational watch alarm system (BNWAS) is to monitor bridge activity and detect operator disability which could lead to marine accidents. The system monitors the awareness of the Officer of the Watch (OOW) and automatically alerts the Captain or another qualified OOW if for any reason the OOW becomes incapable of performing the OOW's duties. This purpose is achieved by a series of indications and alarms to alert first the OOW and, if he is not responding, then to alert the Captain or another qualified OOW. Additionally, the BNWAS may provide the OOW with a means of calling for immediate assistance if required. The BNWAS should be operational whenever the ship's heading or track control system is engaged, unless inhibited by the Captain.
A multipurpose containerfeeder crashed into the DanishGreat Belt Bridge on March 3, 2005 during a trip from Svendborg to Finland. The crash knocked two cranes off the ship, and destroyed the top deck of the ship's bridge. A fire also broke out onboard. The chief officer was at the bridge, and was killed in the crash. Shortly after this accident the Danish Maritime Authority suggested IMO that BNWAS should be mandatory for vessels all over the world.
 
The Danish Requirement in 2002:
 
In 2002 The Danish Maritime Authority adopted the IMO released the resolution MSC.128(75) on performance standard for a Bridge Navigational Watch System (BNWAS) for Danish registered vessels starting with fishing vessels over 15 meters length and later on larger vessels. Only a few systems were available on the market and they were very expensive and too large to fit in a small fishing vessel. This was the reason why we designed and launched our first generation of a BNWAS in 2002 called BW-700 and with great success! The costumers valued the small size and competitive price. We have now supplied more than 700 BW-700 systems for all kinds of vessels.
 
Motion sensor:
 
The BW-800 is delivered with a motion sensor as standard. Normally 1 to 3 motions sensors are needed depending on the bridge design and size. The sensors detect motion on the bridge and reset the internal timer in the BNWAS. These units are installed to minimize stress for the officer on watch because he does not have to activate the reset unit every 3 minutes, if he moves around regularly on the bridge. For safety reasons Uni-Safe Electronics have chosen to use a dual motion sensor with infrared and microwave detection in order to avoid a "non human” motion to reset the timer and a single sensor is not suitable for BNWAS systems.
 
Selector unit:

With a selector unit it is possible for the OOW to select individually any of the navigation officers or the captain as being the assigned back-up officer for receiving the second stage remote audible alarm.

For vessels with DNV NAUT OC/AW notification it is required that the third stage remote audible alarm shall at least sound in the below locations:

Captain’s cabin and office

Officer’s office

Officer’s mess

Officer’s day room

Cargo control room (if provided)

Gymnasium (if provided)

Prayer room (if provided)

Other public rooms and areas (if provided)
  
Emergency call:

If the officer on watch (OOW) needs assistance on the bridge, the BW-800 has an emergency call facility. If the reset unit is activated for more than 2 seconds, the back-up officer will be alerted immediately.

Maintenance free system: 
  
BW-800 has no internal battery back-up and does not require annual maintenance.
BNWAS systems with internal battery back-up requires annual service and battery replacement. In the end, these systems will become very expensive for the vessel owner. 
 
Warranty:

Warranty: 24 months from date of delivery.
 
Exchange policy:
 
If the BW-800 system should fail, we would offer to exchange the defect unit provided it is under guarantee.

Warranty claim procedure:

1) Send a claim to your local BNWAS BW-800 agent containing:

·         Item number

·         Description of the failure

·         Trouble shooting results

·         Serial number of main unit (BW-800)

·         Date of purchase

·         Vessel name

·         Your company details


2) Your local BNWAS BW-800 agent will send you an exchange unit and this unit will be invoiced.


3) Send the defective unit to your local BNWAS BW-800 agent.


4) If the failure is covered by warranty, you will receive a credit note. If not, you will receive an invoice for the repair.

 
The BW-800 has been tested according to specifications from following classification societies:
 

LR Lloyd's Register of Shipping

BV Bureau Veritas

RINA Registro Italiano Navale

ABS American Bureau of Shipping

DNV Det Norske Veritas

GL Germanischer Lloyd

NKK Nippon Kaiji Kyokai

RS Russian Maritime Register of Shipping

CCS China Classification Society

KR Korean Register of Shipping 

 

Wireless BNWAS or not?

We have considered to use wireless BNWAS alarm units, but we think that the solution is too expensive for the vessel. Wireless BNWAS systems has to have a backup battery for every alarm unit if AC power fails. That means that you will have to maintain batteries at all wireless units every year. Inevitability, the cost of checking battery capacity and exchanging batteries will exceed the installation cost in a few years. The alarm units have to be connected to an AC powerline (not with an standard AC plug) and this requires installation too.

We think that the idea of a wireless BNWAS system is good, but it does not give you value for the money…

The easy solution is often not the right solution.

BNWAS Check List
 
BNWAS installation:

The crew can do 90% of the installation (normally installation of cables and units).

Connection to VDR, radar, ECDIS and Autopilot are normally done the next time they have a technician onboard for the annual VDR service. Connection to the VDR is normally most difficult, as the VDR may need a software update if it does not include a BNWAS input (this is the same issue for all BNWAS systems).