A multipurpose containerfeeder crashed into the Danish Great 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.
IMO regulations for BNWAS Regulations from IMO’s Maritime Safety Committee (MSC) requires carriage of a BNWAS Bridge Navigational Watch Alarm System complying with IMO performance standards.
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 Daniamant 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.
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)
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: 24 months from date of delivery.
If the BW-800 system should fail, we offer to exchange the defect unit provided it is under guarantee.
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.
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 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
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.