The pervasive “Beep. Beep. Beep.” of alarm systems has become an “unrelenting soundtrack” for bridge officers and control room engineers on modern ships, often creating such an overwhelming cacophony that it’s difficult for seafarers to discern truly critical warnings from routine notifications. This phenomenon, known as alarm fatigue, poses a significant safety risk in the maritime industry.
The Human Factor in Alarm Response
Volume 1 of the research, based on interviews with 65 maritime professionals across 15 vessels and questionnaire data, initially revealed a generally positive view of alarm system usability. However, it also exposed significant concerns: the design and setup of alarms often failed to adequately consider human limitations, leading to a breakdown in trust and behaviors that could jeopardize maritime safety.
As Asger Christian Schliemann-Haug, Lead Data Scientist at LR Technical Directorate, explains, “Alarm response is not merely an automated process involving deterministic machines; rather, it is a human cognitive and physical process that requires thought, analysis, and action.” He points out that while computer display and data processing have advanced rapidly, human abilities have remained relatively unchanged, making human factors the primary constraint on the number of alarms that can be successfully managed.
Excessive Alarm Loads and “Nuisance Alarms”
Volume 2 of the research provides a more detailed quantitative analysis, benchmarking maritime alarm systems against widely recognized engineering practices from adjacent industries, specifically IEC 62682:2014, EEMUA 191, and ISA TR18.2.5.
A key finding is the alarmingly high daily alarm rates on many vessels, particularly passenger cruise ships. One large cruise ship recorded an average of 105 alarms per hour, significantly higher than the engineering officers’ estimate of just 22. Another large cruise ship averaged 77 alarms per hour. These are not isolated incidents; the report notes peak rates during upsets reaching thousands of alarms within a mere 10-minute window on some vessels, with “alarm floods” sometimes lasting for hours or even days.
Beyond sheer volume, the research addresses the annoyance seafarers feel towards “nuisance alarms.” These are frequent or fleeting alarms that repeat excessively or change quickly without requiring operator action, leading to concerning coping strategies. The study highlights how watchkeepers and shipowners can assess the ‘nuisance score’ or ‘cry-wolf’ factor of their alarm systems.
In one observed cruise ship departure, out of 106 alarms recorded, 34 were explicitly silenced by the watchkeeper because they were deemed repeating, irrelevant, or illogical. The remaining “missing” alarms were either overlooked due to simultaneous occurrences or suppressed by the watchkeeper without subsequent acknowledgment, effectively becoming inactive and unsignaled.
Challenges in Unattended Machinery Spaces (UMS)
The research also sheds light on the situation in ships with Unattended Machinery Spaces (UMS). The UMS concept is designed to reduce staffing by minimizing alarms during rest periods. However, data reveals that a significant proportion of these ships’ operational spectrum—between 38% and 84%—fails to meet this goal. On average, approximately 63% of typical rest periods (between 10 PM and 6 AM) were interrupted by at least one alarm. This directly impacts crew fatigue, undermining the very purpose of UMS in managing the workload for engineering staff.
Actionable Solutions and Significant Reductions
While the “alarm problem” is complex, the research demonstrates that significant improvements are achievable. A critical insight is that a small number of “bad actor” alarms contribute disproportionately to the overall alarm load. On average, the “top 10” most frequent alarms accounted for nearly 39% of the total alarm load. This means that substantial reductions can be achieved with relatively focused effort.
A case study on a large cruise ship demonstrated this potential: by analyzing the top 10 most frequent alarms over six months and collaborating with the crew, a 21% reduction in alarms was achieved in the first week, equivalent to 101,925 fewer alarms over six months. Further information gathered onboard led to an additional 27% reduction, eliminating another 121,600 alarms. Another cruise ship case study showed a 32% reduction in the first seven days using the same data-driven approach, with continuous weekly improvements.
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Source: Lloyd’s Register
