There has been only anecdotal evidence to determine understanding of fatigue
For some years there has been growing concern about the reality of the effects of fatigue on marine safety. Accident investigators have identified fatigue as a factor in a considerable number of casualties, notably aboard small short sea traders in particularly intensive operations, where there have been two watchkeepers working watch and watch.
Is fatigue caused by a lack of sleep? Is performance affected by sleepiness or a period of disturbed sleep throughout a tour of duty where 6 hour watches are the norm? There might seem to be a reasonable link between these factors, but hitherto there has been only anecdotal evidence (apart from those casualties) to determine understanding of fatigue.
Project Horizon, an 11 partner European research study which has seen academic institutions and industry organisations study the effects of fatigue, released its first findings last week. Employing bridge, engine room and cargo simulators, realistic seagoing scenarios were provided for 90 experienced deck and engineer officers who undertook seven day “voyages” on the equipment at Chalmers University of Technology in Gothenburg and Warsash Maritime Academy at Southampton Solent University.
Some officers undertook their “voyages in a 4 on, 8 off regime, while others worked 6 on, 6 off. Some were exposed to a “disturbed” off-watch period, reflecting the realities of life in port with shore-side demands, or bad weather at sea. The research provided detailed empirical data on the sleepiness levels of watchkeepers, and it was possible to measure and analyse the impact of sleepiness on decision-making, reaction times and other important elements of performance.
The findings released so far provide scientific credibility to anecdotal beliefs that have been accumulating for many years, and suggest that performance really does deteriorate with sleepiness. It was, for instance, found that at least one occurrence of sleep was detected among 45% of the 6/6 team when on the 0000-0600 watch, and one occurrence for about 40% of those on the midnight to 0400 watch on the shorter patterns. Those working 6/6 were found to get markedly less sleep than those on the 4/8 pattern, while reaction times, tested at the start and completion of each watch showed clear evidence of performance deterioration and the slowest reaction times were found at the end of night watches and among those working the 6 hour watches.
Disturbed rest periods were found to have a profound effect upon sleepiness levels. The longer watch period was found more tiring than the shorter, while there was evidence that while routine and procedural tasks could be carried out with little or no degradation, “novel” events such as collision avoidance or fault diagnosis caused more problems as the “voyages” progressed.
The analysis of an enormous amount of data gathered during the “live” part of the project will continue, but it is hoped the research will lead to a new fatigue management “toolkit” for use by owners and operators, seafarers, regulators and others, possibly enabling them to arrange working schedules to mitigate risks caused by fatigue. A scientific understanding of fatigue applied to those involved in ship operation will also be very valuable. It is hoped that a further detailed report will be available in a forthcoming BIMCO Bulletin.
Source: BIMCO, Watchkeeper