Thome Ship Management Addresses BNWAS Issue Aboard Oil Tanker

Overview of the BNWAS Issue on M.T. "Hafnia Lotte

Recently, we were contacted by a superintendent from Thome Ship Management regarding an issue with the BNWAS (Bridge Navigation Watch Alarm System) aboard the M.T. "Hafnia Lotte". The BNWAS is designed to monitor bridge activity and alert the captain (or other qualified personnel) if the bridge appears to be unmanned.

Technical Challenges in BNWAS Repair and Solutions

The monitoring system consists of a main controller, reset button boxes, motion sensor boxes, and alarm boxes. When activated, the BNWAS enters standby mode for a period between 180 and 720 seconds, which can be set by authorized personnel. If this period expires without a crew member resetting the BNWAS, the visual alarm is activated. If not reset thereafter, the buzzer sounds, and the 1st phase alarm is activated. After a period of 15 to 60 seconds, the 2nd phase alarm will be activated. If the unit is still not reset, after a period of 90 to 180 seconds, the 3rd phase alarm will be activated.

Initial Contact by Thome Ship Management

On the "Hafnia Lotte", the captain and CO explained to our service engineers that there were issues with resetting the unit. The service engineers began by checking the wiring. After inspecting the wiring, it became clear that something was amiss. It was only a matter of time before the system would fail. After fixing the wiring, everything was checked again. Then, the reset button boxes located on the steering console, port wing, and starboard wing were also inspected.

Understanding BNWAS and Its Operational Significance

It also turned out that the BNWAS was not functioning properly. Using a spare unit that the service engineers had with them, various timers could be exchanged and set.

After a full system test was carried out, everything could then be signed off as "fully operational".

The "Hafnia Lotte" is a medium-sized oil product tanker currently managed by Thome Ship Management. Thome Ship Management is one of the world's largest independent ship managers with its headquarters in Singapore.

Introduction to Marsen's Technological Contributions

Since 2013, Ravebo has represented the company Marsen. Marsen is based in Busan, Korea, and specializes in providing measuring sensors.