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1 Safety is a major concern in all freight operations with human error often being a key factor in incidents and accidents. Fatigue increases the risk for human error, which is why manag- ing fatigue should be a key component of any safety management system (SMS). For many years the usual way to manage operator fatigue has been to limit work hours, and while there is still a place for a scientifically valid restriction on work hours to reduce operator fatigue, many industries view this as simply one element in what would ideally be a larger program, such as a Fatigue Risk Management System (FRMS). A key premise that is used to justify the need to provide adequate rest intervals is the gen- eral consensus that 7 to 8 hours of sleep per 24-hour period is required to maintain acceptable levels of alertness, minimize fatigue, permit optimum performance, and maintain health. An element that is often missing from the discussion of adequate rest intervals in the maritime sector is that in order to obtain 7 to 8 hours of consecutive sleep, rest intervals may need to be as long as 24 hours (Roach et al. 2003). Rest intervals of this duration are unlikely to be feasible in any operational setting. So while the premise that sleeping for 7 to 8 hours per day is optimal and is not generally disputed, there have been several recent studies suggesting that a sleep episode may not need to consist of 7 to 8 consecutive hours in order to maintain adequate levels of performance. These studies suggest that even when sleep is split into more than one episode per day, often referred to as an anchor-sleep/nap-sleep strategy, that per- formance is comparable, and in some cases, better than when the same duration of sleep is obtained in a single sleep period (Mollicone et al. 2007, Mollicone et al. 2008, Jackson et al. 2014, Kosmadopoulos et al. 2014, Short et al. 2014). While a long-standing and preferred practice of crews in the U.S. tug/towboat/barge indus- try has been to have work/rest schedules that alternate in 6-hour shifts, commonly referred to as a âsquare watch system,â this new scientific data has important implications for manag- ing fatigue in the maritime industry. Each crew member has a total of 12 hours on duty with 12 hours off duty per 24 hours, and it has been customary for crew members to obtain sleep during both of their 6-hour off-duty periods. In addition, other schedules that are employed when requiring two persons to be on duty constantly over a 24-hour period have involved rectangular watches (e.g., 7 on: 7 off: 5 on: 5 off; 8 on: 8 off: 4 on: 4 off) or watches that require 12 hours on duty: 12 hours off duty. While there are no hours-of-service regulations beyond the 15-hours-on-duty limit, 46 United States Code (U.S.C.) 8904(c) gives the U.S. Coast Guard (USCG) authority to establish them. The USCG (Federal Register/Vol. 76, No. 155, August 11, 2011/Proposed Rules) stated that it was considering, ârequirements to increase uninterrupted sleep dura- tion to a threshold of at least 7 consecutive hours in one of the two available off periods. . . .â Strict adherence to such requirements would ban the most common work schedules in the Enhancing Sleep Efficiency on Vessels in the Tug/Towboat/ Barge Industry S U M M A R Y
2 Enhancing Sleep Efficiency on Vessels in the Tug/Towboat/Barge Industry tug/towboat/barge industry. There is currently no scientific data to support such a change in hours of service. However, there is good scientific evidence that it would not be possible to obtain 7 hours of uninterrupted sleep during a 7-hour off-duty period if sleep is attempted at a time when the internal 24-hour biological clock is in the âwake mode.â With these issues in mind, the primary goal of this project is to propose evidence-based best practices to improve sleep on schedules requiring a split-sleep period and reduce fatigue in crews working in the tug/towboat/barge industry in the U.S. A key part of achieving this goal is to determine the use and impact of anchor-sleep/nap-sleep strategies in this industry. To this end, several approaches were used, including surveying crew and management in the tug/towboat/barge industry about practices related to enhancing sleep, mining previ- ously collected sleep, health, and work data from crews working the 6:6:6:6 square watch, and reviewing related practices from other industries. The results from data collected by the research team from crew members in the tug/towboat/ barge industry indicate that in the over 200 crew members studied, an anchor-sleep/nap-sleep strategy was used 96% of the time and that the factors that predict sleep duration include time of day, stress, anxiety, discomfort, sleep disruption (noise being the most commonly reported), general health, and fatigue level. These are all factors commonly reported to impact sleep in other populations, but while the causes of sleep disruption may be universal, the practices that will need to be implemented to reduce the impact of these factors may in some cases be unique to this industry. In addition to examining sleep and health in crew members, the research team also surveyed management to determine the proportion of companies that use many of the practices suggested as part of this report. Results from these surveys indicated that, for the most part, companies were actively addressing factors that impact sleep, but that in some key areas, there was room for improvement and/or further research, as well as a need for tracking how effective company policies were in allowing crew members to obtain adequate sleep. The best practices suggested here are drawn from the research teamâs research within the tug/towboat/barge industry and also from the experience of other transportation industries. A variety of sources, including government and private companies, were studied to gather information. Where appropriate, interviews with key personnel were conducted to garner fur- ther insight into the development and implementation of various practices that were not read- ily available from published sources. A key component of the research teamâs approach in this regard was to not âreinvent the wheel,â but to determine which practices were likely to have the greatest impact, provide evidence of this, and discuss relevant issues that ideally would be considered in the implementation of these practices in the tug/towboat/barge industry. Proposed Best Practices The need for best practices related to sleep/fatigue in the tug/towboat/barge industry is not new; in fact, it has been 12 years since the USCG published the report Crew Endurance Management Practices: A Guide for Maritime Operations (Comperatore and Rivera 2003), and 10 years since an addendum (Emond et al. 2005) was published. The basic proposal was for tug/towboat/barge operators to establish a crew endurance management system (CEMS) that could be adopted across the industry to reduce fatigue on board vessels in order to reduce accidents that were due, at least in part, to fatigue. Many of the recom- mendations involved improving the work environment and scheduling changes that would enhance sleep quality and duration. While many of the recommendations were adopted by some parts of the maritime industry, surveys of 40 wheelhouse crew members and man- agement from 46 companies have established that a CEMS is not well represented in the
Summary 3 industry and there has been little attempt to measure if the recommended best practices in a CEMS actually increased sleep time or reduced fatigue. Furthermore, over the past few years a number of advances have been made in understanding the key role of split-sleep schedules and napping, in addition to new technologies and approaches, to control fatigue. These findings can now be incorporated into the best practices to enhance sleep duration and sleep efficiency. Based on the findings of the current research and the investigatorsâ experience and knowl- edge, the following best practices are proposed for implementation in the U.S. tug/towboat/ barge industry. â¢ Develop and implement a FRMS. â¢ Develop updated educational materials and standardize dissemination and testing practices. â¢ Establish stress management policies/programs. â¢ Monitor and develop strategies to reduce the impact of excessive commute times. â¢ Implement fatigue reporting practices/fitness-of-duty requirements. â¢ Provide health and wellness programs. â¢ Consider establishing a registry of registered medical examiners. â¢ Initiate screening and guidelines for management of sleep disorders, in particular, obstruc- tive sleep apnea. â¢ Develop programs for ongoing monitoring and review of all best practices. â¢ Provide access to good nutrition. â¢ Provide access to exercise equipment and resources. â¢ When applicable, utilize fatigue modeling. â¢ Enhance the sleep environment. â¢ Encourage and support split-sleep strategies when appropriate. â¢ Develop a process for crew to report missed sleep opportunities and practices to address any related fatigue. The key that can link all of these practices is a well-developed FRMS that can be developed as part of a companyâs SMS. It will also be important to fully assess the implementation by tug/towboat/barge personnel of existing educational materials, such as the USCG Crew Endurance Management Practices site (http://www.uscg.mil/hq/cg5/cg5211/cems.asp) and other industry materials, to aid in the optimization of such strategies. Future Directions There are several key factors that still need to be addressed; these include further research on split-sleep schedules and alternate work start times in operational settings, monitoring and follow up on practices that are implemented to ensure that they are having the intended effect, and an assessment of the outcomes of these practices on safety. While not optimal, simulator studies may initially be a useful way of conducting studies to assess the impact on sleep; the limitations of such studies are that crew would not be sleeping on a vessel with all of the inherent noise, vibration, and other factors that are unique to vessel operations. Perhaps the biggest impact on sleep duration is time of day. Transportation requires crew to work 24 hours a day, which means that someone is always trying to sleep during the day. Simulation and/or fatigue modeling represent an important initial step to start examining the impact of scheduled work start and end times to minimize or distribute the impact of having to sleep at times when the circadian alerting signal is high. By knowing the times when risk is highest, tasks that are by nature more safety/fatigue sensitive could be scheduled to occur at times of lowest risk.
4 Enhancing Sleep Efficiency on Vessels in the Tug/Towboat/Barge Industry Another consideration is the widespread use of 12-hour shifts, the second most commonly used schedule in the tug/towboat/barge industry (reported to be in use by 20% of surveyed companies). There has been little research focused on the use of 12-hour shifts in this set- ting. Given the variety of ways that this schedule is operationalized, the use of individualized FRMS will be important and many of the recommendations in this report are also applicable to this schedule. There is a need to provide guidance to individual companies for the development of an FRMS and to consider the size of and resources available to each company. This guidance could be developed by industry organizations such as the American Waterway Operators, as well as by government in collaboration with the industry and its workers. Another area of need is the development of new, improved, and scientifically validated risk mitigation strategies that are appropriate for the type of work schedules in the maritime industry (two work and two rest periods/24 hours). A few example questions representative of this area of study follow: â¢ When crew are already using an anchor-sleep/nap-sleep strategy, what is the best way to use caffeine and naps, which are the most commonly proposed mitigation tools? â¢ Since not all currently proposed practices seem to be sufficient, are there better ways to reduce noise? â¢ What are the sources of stress for workers (personal/health and/or work related)? How can tools and strategies be developed within a company to deal with the source of the stress that is most common in their operations? â¢ What is the assessment of the utility of new technologies, such as personal fitness trackers, to aid crew in self-monitoring behaviors, including sleep, nutrition, and physical activity? To achieve these goals, employees, companies, industry groups, and regulators will need to work together. Final Thoughts Prescriptive hours of service (HOS) are not likely to be the most effective way to increase sleep durations and improve sleep quality or to manage and reduce the impact of fatigue. Further research is needed to determine whether longer rest intervals are optimal or even required when schedules have more than 1 work and rest interval per 24 hours. The unique nature of many tug/towboat/barge operations makes these types of schedules necessary, for example, to avoid excessive time on task. Given new scientific data that suggests that anchor- sleep/nap-sleep schedules might actually be as effective or in some cases better than a sched- ule involving a single rest period per day due to a balance between homeostatic and circadian control of sleep and alertness levels, further consideration is needed before changes to the current HOS rules are initiated. As part of this process, an assessment and better manage- ment of the factors that impede optimizing sleep efficiency and the recuperative value of sleep should be undertaken.