In modern ship bridge management, ensuring that the bridge is always manned is a key step in preventing accidents such as collisions and grounding. The International Maritime Organization (IMO) has clarified the performance standards for Bridge Navigation Duty Alarm Systems (BNWAS) through MSC. 128 (75) resolution, particularly for vessels operating on a single bridge, which must have reliable activity monitoring and alarm transfer capabilities. The Bridge Watch Monitoring System (BWMS) launched by Kongsberg Maritime is a professional solution that meets this requirement.
However, any electronic system that operates at sea for a long time will face issues such as aging, false alarms, communication interruptions, or configuration errors. For engineers and electronic and electrical personnel, mastering the installation and debugging points, daily operation procedures, and quick troubleshooting methods of BWMS is the core skill to ensure navigation safety and reduce unplanned shutdowns. This article is based on the technical specifications and practical application experience of BWMS, systematically sorting out the complete knowledge system from hardware installation to software configuration, from duty logic to alarm linkage, and providing troubleshooting steps and maintenance suggestions for typical faults.
Overview and Core Functions of BWMS System
2.1 Design Objectives and Compliance
BWMS is an intelligent monitoring system specifically designed to monitor the activity status of bridge personnel. When there is no one on duty on the bridge or the on duty driver loses the ability to operate due to health reasons, the system first emits an audible and visual alarm locally on the bridge. If there is no response, the alarm will be automatically transferred to the captain or other qualified backup navigator. This design fully complies with the technical requirements of IMO MSC. 128 (75) for BNWAS and is applicable to all types of vessels, especially those that have obtained the "one person bridge" classification symbol.
2.2 Main Function List
Central bridge alarm panel: Centralized display of visual and auditory alarms from various navigation devices and systems (such as radar, electronic chart, autopilot).
On duty status monitoring: Automatically detect whether there is personnel operation response in the bridge building based on configurable time intervals. If there is no interaction after the timeout (such as buttons, touch screen clicks, or radar/CDIS operations), the system will determine that there is no one on the bridge or the driver is disabled.
Hierarchical alarm transfer: The first level alarm is triggered locally in the bridge unit; If it is not confirmed or reset within the specified time, the second level alarm will be automatically sent to the captain's cabin or designated location; If there is still no response, further call the backup navigator (such as the first mate or second mate). The transfer path and delay time can be customized.
Manual call for backup navigator: The on duty driver can initiate a call for backup personnel at any time through dedicated buttons on the bridge deck panel without waiting for timeout.
Hardware composition and technical specifications
3.1 Core modules
BWMS adopts a modular design, and the main hardware includes:
Bridge alarm panel: human-machine interaction core, including LCD display, status indicator lights, buzzer, function buttons (system start stop, mute/confirm, timer adjustment, backup call, etc.). The panel supports desktop, ceiling, wall bracket or embedded installation (fixed by hidden screws in corners).
Distributed Processing Unit (DPU):
RDi-32: Input processing unit, used to collect external sensor signals (such as buttons, motion detectors) or alarm contacts from other devices.
RDo-16: Output type processing unit that drives external alarm light bells, relays, or sends signals to the onboard alarm management system.
Midi operation station (MOS-33): a terminal used for system configuration and parameter adjustment, usually placed in the control room or electrical room. Through MOS, advanced operations such as defining the number of navigators, editing alarm description text, and setting alarm grouping logic can be completed.
Power Switching Unit (PSO AD-00479): Automatically switches to the backup DC power supply when the main power supply loses power or fluctuates, ensuring uninterrupted operation of the system.
3.2 Detailed Electrical and Environmental Specifications
Parameter indicators
Supply voltage 18-32 VDC, allowable ± 5% ripple
Typical power consumption 26 W
Working temperature -15 ℃ to+70 ℃
Maximum humidity of 96%, no condensation
EMC compliance IACS E10, IEC 60945 4th edition
The protection level depends on the installation method of the panel, and the front is usually IP22 or higher
3.3 Classification Society Type Certification
BWMS has been recognized by mainstream classification societies worldwide, including DNV, BV, GL (now merged with DNV), RINA, NK, ABS, KR, PRS, MRS (Russian Classification Society), CCS (China Classification Society). This means that the system can be directly installed on any vessel flying any relevant flag without the need for additional testing.