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Impact on Wives and Families | Work and Sleep Patterns | Implications for Fatigue Management
The work practices of Marine Pilots: a review
4.0 WORK AND STRESS
Occupational stress arises when perceived work demands exceed an individual’s resources and capabilities (Hockey et al. 1989; Mendelson 1990). This source of stress is a function of several interacting variables including the nature of work tasks, the work environment, personal characteristics and the level of support available to the person (Cox & Griffiths 1995). A person’s perceptions are an important determinant of the amount of occupational stress experienced and as a consequence, it is difficult to quantify the stressfulness of work conditions. However, conditions which have the potential to induce stress have been identified (Kasl & Amick 1995), and in the following section, the main aspects of marine pilotage work which may contribute to pilot stress are detailed.
4.1 Irregular Timing of Pilotage Work
A potential source of stress for marine pilots is the irregular timing of their work. Work undertaken during unconventional hours of the day places greater demands on employees than work performed during normal daytime hours. This has been substantiated by investigations showing night work to be more taxing than day work, as indicated by greater decrements in performance and well-being (Bohle & Tilley 1989; Meijman et al. 1993; Totterdell et al. 1995). Similarly, the early rising time associated with early morning work seems to cause additional strain for workers (Bauer 1993; Kecklund et al. 1997).
The increased levels of stress associated with irregular work hours relates to the impact such hours have on circadian rhythms, sleep and social and domestic factors (Monk 1989; Monk & Folkard 1983, 1992). As encapsulated in the model developed by Monk (1989) (Figure 4), these three interrelated areas affect a person’s coping ability. For strain to be completely absent, each area must be functioning well (Monk 1989; Monk & Folkard 1992). Hence, if a worker is facing imminent divorce because his partner is dissatisfied with the home/work situation, strain will be experienced irrespective of how well circadian rhythms have adapted or the quality and quantity of sleep achieved. It is therefore important that all three areas are addressed when considering the impact of irregular work hours on employee stress (Monk 1989; Monk & Folkard 1992).
4.1.1 Circadian Factors
Circadian rhythms are cyclical variations in biological functions and behaviours which recur approximately every 24 hours (Griffiths 1993; Luna 1997; TSB 1997). Through the presence of social and environmental time cues (referred to as zeitgebers), these rhythms have become entrained to maximise wakefulness and activity during the day, and induce sleep at night (Folkard 1996a; Monk 1991; Monk et al. 1997; Monk & Folkard 1983, 1992; TSB 1997).
Work performed during unconventional hours of the day causes disharmony between a person’s circadian rhythms and the normal social and environmental zeitgebers. As a consequence, circadian dissociation occurs (Griffiths 1993; Luna 1997; Rosekind et al. 1996; Scott & Ladou 1990). In such situations, people oppose the normal diurnal nature of the human body by attempting to maintain high levels of alertness when their body is anticipating sleep, and by trying to sleep when alertness and arousal are naturally increasing. This induces a sub-optimal psychophysiological state (de Vries-Griever & Meijman 1997) which may manifest in the form of increased fatigue, mood deterioration and performance decrements (Condon et al. 1988; Luna 1997; Monk 1989; Monk & Folkard 1992: Rosekind et al. 1996). Additionally, there is substantial evidence which suggests long term health consequence may arise (Costa 1996; Griffiths 1993; Monk & Folkard 1992; Scott & Ladou 1990).
While it is possible for circadian rhythms to adjust to unusual work routines, the process is slow and is inhibited by the presence of social and environmental zeitgebers (Monk 1989; Monk & Folkard 1983, 1992;
Samel & Wegmann 1987; TSB 1997). As a consequence, there is generally little, if any circadian adjustment to work schedules involving frequent changes in work times (Colquhoun 1985; Colquhoun et al. 1987; Costa 1993; Luna 1997; Monk & Folkard 1992; Samel & Wegmann 1987). In fact, even permanent night workers typically fail to exhibit complete circadian adjustment to their nocturnal work routine, as during time off they revert back to a day orientated schedule (Folkard 1996a; Luna 1997; TSB 1997). In light of these findings, there is a high probability that many marine pilots may experience circadian dissociation. Lending support to this proposal is the finding that epinephrine, norepinephrine and cortisol secretion patterns of Port Phillip sea pilots all show significant deviations from expected circadian patterns (Berger 1987).
4.1.2 Sleep Factors
As was identified in the previous section of this report, schedules which incorporate work outside normal hours are associated with compromised quality and quantity of sleep, and a higher prevalence of sleep disorders (such as insomnia). In turn, the demands on the employee are increased as greater effort is required on the worker’s behalf to overcome the fatigue and performance decrements induced by poor sleep.
4.1.3 Social and Domestic Factors
Irregular work hours can create a plethora of social and domestic problems for the worker (Monk 1989; Monk & Folkard 1983, 1992). Great Barrier Reef pilots indicated that the home-work interface (i.e. the transition from home to work and vice-versa) was the most stressful aspect of their work (Parker et al. 1997). This finding is consistent with what has been reported by other Australian seafarers (Parker et al. 1997), partners of Australian seafarers (Foster & Cacioppe 1986) and a group of US commercial airline pilots (Cooper & Sloan 1985). Dissatisfaction has also been expressed by marine pilots about their inability to commit themselves to regular outside interests, and over the fact they are often required to cancel appointments and plans due to unexpected work (Berger 1984; Shipley 1978; Sparks 1992).
The social and domestic problems induced by irregular work schedules have also been reported by other groups of shiftworkers. German nurses working morning shifts beginning at or before 0600 hours indicated married life was made more difficult due to differences in work patterns between partners, and that early starting times were incompatible with having dependent family members, such as young children or elderly parents at home (Bauer 1993). Additionally, many nurses expressed dissatisfaction over the social isolation experienced as a consequence of their irregular work hours (Bauer 1993). Likewise, 8 and 12 hour shiftworkers from a North American petrochemical company had lower levels of satisfaction with the amount of time available to them for personal and family pursuits, as compared to day workers (Jaffe et al. 1996).
The social and domestic problems experienced by shiftworkers and others involved in irregular work schedules can, at least in part, be attributed to the disalignment of their work and leisure times from society ‘norms’. All workers rate the evenings and weekends highest in terms of leisure time value (Hornberger & Knauth 1993), and hence work performed during these times interferes with the person’s ability to make regular contact with friends and relatives (Knauth & Costa 1996).
Additionally, it is not only the worker who experiences social and domestic strain as a consequence of irregular work hours, but also the worker’s partner and family. In a study of the perceptions and feelings of shiftworkers’ partners, more than 50 percent of respondents indicated that their partner’s work schedule disrupted their personal and joint social life, created conflict in their relationship with their partner and limited the amount of contact their partner had with their children (Smith & Folkard 1993).
Similarly, a survey of 52 wives of Australian seafarers revealed that 83 percent of the wives experienced stress when their partner was due home and due to return to sea, and 79 percent of children were perceived by their mothers as experiencing stress prior to and after the arrival home of their father (Foster & Cacioppe 1986). That the wives of marine pilots have expressed dissatisfaction over the disruption induced by their husband’s work schedules and the difficulties in planning family and social events (Berger 1983; de Vries Grierer 1982), suggests the partners’ of marine pilots are not immune to the social and domestic strain caused by irregular work schedules.
4.1.4 Moderating Factors
Certain individual characteristics are able to moderate the amount of stress experienced as a function of irregular work hours. The two personality traits of ‘morningness/eveningness’ and introversion/extroversion are related to circadian phasing and influence a person’s adaptation to irregular work hours (Folkard 1983, 1996a; Harma 1993; Monk & Folkard 1983, 1992). Morning people and introverts are more alert during the morning and have slightly earlier peaks in their temperature rhythm than evening people and extroverts (Folkard 1983; Harma 1993; Monk & Folkard 1983, 1992). As a consequence, the former group tend to adapt less well and have a lower tolerance for night work (Folkard 1983; Harma 1993; Monk & Folkard 1983, 1992).
Poor levels of physical fitness can reduce one’s ability to handle the stresses associated with irregular work hours. In a group of shiftworkers who underwent a 4-month training program, the significant increases in maximal oxygen consumption which occurred were accompanied by reports of less general fatigue, fewer musculoskeletal complaints and increased sleep duration. While no evidence of a direct interaction between fitness level and circadian rhythms was found, it appears that higher levels of physical fitness may improve tolerance to shift work through other avenues (Harma 1993).
Increasing age negatively affects tolerance for irregular work hours as changes in the sleep-wake cycle occur and there is a tendency for people to become more morning orientated as they age (Folkard 1996a; Harma 1993; Monk & Folkard 1983, 1992). Additionally, people with a smaller temperature rhythm amplitude and who maintain higher levels of positive moods over a sleepless 24 hour period prior to entering shiftwork, may adapt more easily and have greater tolerance for working irregular hours (Vidacek et al. 1993).
While each of the above personal characteristics can influence tolerance for irregular work hours, it has been suggested that the most important factor may be commitment to a work schedule (Harma 1993; Monk & Folkard 1983). Commitment implies the person’s willingness to schedule their lives, and especially their sleeping habits, around their job. Several studies (Barton et al. 1993; Barton 1994; Verhaegen et al. 1987) have compared nurses and midwives who freely chose to work permanent night shifts to those staff on rotating shifts involving predominantly day work but some night work. Results revealed that night work caused fewer sleep, social and domestic problems in permanent night shift nurses, due to their greater commitment in scheduling their lives so as to minimise the disruption caused by night work (Barton et al. 1993; Barton 1994; Verhaegen et al. 1987).
The complete irregularity of pilotage work makes it somewhat more difficult for marine pilots to schedule their lives around their job. Pilots often have little advanced warning of when their next work assignment will be and the variable starting and finishing times prevent pilots from establishing a daily routine.
4.1.5 Summary
In summary, the interacting and compounding effects of circadian dissociation, poor sleep and social and domestic problems arising from the irregular timing of pilotage work, can significantly contribute to the stress experienced by marine pilots. These factors may reduce the psychophysiological state of the person, such that a higher prevalence of fatigue, reduced levels of well-being and performance decrements manifest. In the long term, health may also be adversely affected. Individual characteristics such as personality traits, level of physical fitness, age and commitment to a work schedule, play an important role in the adaptation and tolerance for work outside normal hours.
4.2 Long Working Hours
Long working hours increase the demands placed on workers by requiring greater effort to maintain performance levels in the face of heightening fatigue, and by increasing exposure to other workplace stressors (Spurgeon et al. 1997). This has been evidenced in a number of occupational groups. Intensive care unit nurses involved in 12 hour shifts reported higher levels of chronic fatigue, cognitive anxiety and emotional exhaustion, as compared to nurses working 8 hour shifts (Iskra-Golec et al. 1996).
The long working hours and resultant sleep deprivation experienced by physicians undergoing residency training adversely affects mood (Dreary & Tait 1987; Nelson et al. 1995) and has been associated with a higher prevalence of somatic symptoms such as ‘feeling run down’ and ‘feeling ill’ (Baldwin et al. 1997). Work performance may also be impaired as indicated by subjective reports (Baldwin et al. 1997) and objective measures of short term memory function (Dreary & Tait 1987) and creative thinking (Nelson et al. 1995).
An investigation examining the effect of overtime work on the cognitive performance of automotive workers (Proctor et al. 1996) revealed that workers who had engaged in overtime work during the week prior to testing, performed significantly worse on tests requiring attention and executive function skills than workers who had undertaken no overtime (Proctor et al. 1996). Mood was also found to be adversely affected, as there were increased ratings of depression, confusion and fatigue amongst workers who had performed overtime work (Proctor et al. 1996).
As marine pilots, and in particular GBRP, are often required to undertake prolonged on duty periods, it is possible they may be susceptible to stress from this aspect of their work.
4.3 Boredom
Situations of work underload can induce stress (Cox & Griffiths 1995; Fisher 1993; Hockey et al. 1989; Melamed et al. 1995) and hence, the high levels of vigilance, watchkeeping and monitoring required of marine pilots may act as stressors (Dyer-Smith 1983a, b). These tasks, which are typically conceived as representing work underload (Melamed et al. 1995), require constant attention yet provide little stimulation. As a consequence, prolonged exposure typically reduces physiological arousal and causes boredom in most people (Dyer-Smith 1983a, b; Fisher 1993; Melamed et al. 1995).
A study which examined factors associated with work-induced fatigue (Finkelman 1994) supported the concept that work underload can lead to reduced levels of arousal. A computer survey of the records of 3,705 temporary employees who had reported experiencing fatigue during their work assignments, revealed that lack of job challenge, inadequate information processing demands and low levels of job control were factors frequently associated with fatigue (Finkelman 1994). Similarly, physiological evidence in the form of heart rate measurements (Cook & Shipley 1980) and EEG and EOG data (Cabon et al. 1993) indicates work underload results in reduced levels of vigilance and fatigue.
The stressful aspect of work underload seems to be the conflict between the need for sustained alertness and the arousal reducing qualities of the task (Dyer-Smith 1983a; Melamed et al. 1995). In these situations, workers are required to exert additional effort in order to maintain appropriate levels of arousal (Costa 1993; Dyer-Smith 1983a). While performance decrements may or may not manifest, the greater effort invested by employees induces earlier and more severe fatigue (de Vries-Griever & Meijman 1987; Hockey 1997). This is especially true during nightwork when the fatigue bought about by light workloads exacerbates pre-existing fatigue from other potential stressors such as circadian dissociation, an acute or chronic sleep debt and long working hours (Luna 1997).
4.4 The Work Roster System
The type of work roster systems used in certain pilotage regions may impact on the stress experienced by pilots. Stable work roster systems in which pilots are advised of their duty periods and time off in advance, seem to cause less disruption to the pilot’s family life and interfere less with eating and sleeping habits (Shipley & Cook 1980). Job satisfaction also tends to be higher amongst pilots on more stable work roster systems (Shipley & Cook 1980; Sparks 1992) and lower levels of sick leave reported (Sparks 1992). Additionally, there are fewer reports of ‘near misses’ when pilots are involved in more stable roster systems (Sparks 1992). It would therefore seem that the greater predictability associated with this type of roster system causes less strain and fewer personal problems for pilots (Shipley & Cook 1980).
4.5 The Uncertainty of Pilotage Work
Pilotage work is associated with much uncertainty, as often pilots are unaware of when their next work assignment will be until they receive the phone call informing them of the ship’s estimated time of arrival or departure. As a consequence, stress may be experienced over this aspect of the work as the pilot’s personal life can be significantly disrupted (Berger 1984; de Vries-Grierer 1982; Shipley & Cook 1980; Sparks 1992). The pilot’s ability to plan ahead and organise personal, family or social events is severely limited (Berger 1984; Shipley & Cook 1980; Sparks 1992), and the uncertainty of pilotage work is often cited as a source of domestic tension (de Vries-Grierer, 1982; Shipley, 1978). Comments made by other groups of Australian seafarers about the adverse affects of the uncertainty of their work, are consistent with those made by marine pilots (Parker et al. 1997).
Additionally, it has been recognised that the uncertainty experienced during the on call period prior to a work assignment can adversely affect the mood and well-being of marine pilots. An investigation of 7 pilots from the United Kingdom revealed that during the on call period, self ratings of tension progressively increased due to the pilot’s increasing level of concern over whether he would be required to work and what type of job he may be assigned to (Cook & Shipley 1980).
4.6 Commercial Pressures
Changes arising as a consequence of greater commercial pressures may indirectly increase the stress associated with marine pilotage. It has been documented that some shipping companies are cutting running costs by minimising the amount of maintenance and upgrading work being performed on their vessels, and by employing cheap seafaring labour (NRC 1994). Hence, a greater load is placed upon pilots who are required to safely guide substandard ships through difficult waters, whilst working with substandard crews (NRC 1994). Reports also exist which indicate that in certain situations the full load of passage planning and safe navigation is being placed upon the pilot, as the master of the ship is either too fatigued or unable to communicate with the pilot to provide any support (NRC 1994). Additionally, reduced crew sizes and the need for rapid port turnaround times have resulted in greater workloads for all shipboard personnel (NRC 1994).
Recent commercial changes have added to the stress being experienced by GBRP. Since the formation of the three separate pilotage companies, there have been great fluctuations in work availability for the different pilotage groups. As a consequence, concern has been expressed by pilots over issues such as job security and personal income (Personal Communication - Pilot Advisory Group 4 August, 1997).
4.7 Onboard and Environmental Conditions
There are many aspects of a ship’s physical environment which can impose strains upon personnel. Noise and mechanical vibrations propagated from engines, generators, ventilators and air conditioning units are present at all times during a voyage. Both of these factors have been associated with increasing levels of discomfort and fatigue as a function of exposure time (Kjellberg et al. 1985; Kokosy 1989; Osler 1997; Pelmear 1995; Rosler 1994). Noise and vibration also contribute to poor sleep (Osler 1997; SIRC 1996) and interfere with communication (Oborne 1995). Additionally, in the long term there may be detrimental effects on the person’s health (Filikowski 1989; Kokosy 1989; Oborne 1995; Pelmear 1995; Rosler 1994).
Rolling and pitching of ships tends to be minimal when aboard large cargo carriers, however it is a factor which pilots have to contend with when travelling to and from work assignments in launch vessels and when working aboard smaller ships. The constant motion of smaller vessels can be extremely onerous, even for experienced sea personnel, and rough weather further exacerbates the conditions (Filikowski 1989). The relatively high prevalence of sea sickness amongst marine pilots may be indicative of this occupational hazard (Shipley 1978). Additionally, as ship motions are mainly counteracted by motions in the lower extremities and lumbar spine, physical strain is induced in these parts of the body (Torner et al. 1994).
The design and working condition of the bridge can impact on the stress experienced by marine pilots. Modern navigational equipment which is in good working order can significantly reduce the strain associated with piloting vessels, as it enables rapid access to accurate information relevant to piloting (NRC 1994). However, in many situations the equipment on board vessels tends to be somewhat outdated and often in a poor state of repair. This in turn substantially increases the load placed on pilots, especially when guiding vessels through difficult navigation regions (Personal Communication - Pilot Advisory Group 18 September 1997).
The lighting conditions on the bridge are important. Bright lights assist in maintaining arousal however, at night, it is beneficial to have the bridge interior somewhat dimmed to enable quick adaptation of the eye to the outside surroundings (Heinecke & Dahlmann-Heinecke 1989). Additionally, it has been identified that the colour and brightness of display units influences information retrieval. Ideally there should be as little difference as possible between the outside environment and the colour of display backgrounds. At night it is therefore preferential to have a dark background, whereas during the day a light background is more favourable (Heinecke & Dahlmann-Heinecke 1989). Textual messages should be presented in a contrasting colour to the background to improve legibility (Heinecke & Dahlmann-Heinecke 1989; Oborne 1995). As a consequence, bridge systems which are adaptable have the greatest potential for reducing strain, as they allow the watchkeeper to alter the bridge set up so as to suit his own preferences and accommodate the outside conditions (Heinecke & Dahlmann-Heinecke 1989).
Furthermore, environmental conditions can significantly impact on stress levels. Unfavourable weather, poor visibility and high density shipping traffic are but a few of the factors which can place greater demands on pilots when guiding vessels through difficult waters (Filikowski 1989; Personal Communication - Pilot Advisory Group 18 September 1997).
It is therefore evident that the onboard and environmental conditions can contribute to overall stress levels experienced by personnel. These factors on their own may not be significant stressors; however in their presence, operators are required to exert more effort in order to accomplish a given task, thereby giving rise to fatigue (Boucsein & Ottmann 1996; Oborne 1995). Additionally, in situations of work overload and/or when combined with other stressors, the stress factors identified above have an additive effect which can negatively affect performance, mood and health (Oborne 1995).
4.8 Non-Work Related Issues
The stress experienced by marine pilots as a function of their work may be intensified by concern over non-work related issues. Findings from the aviation industry have indicated that factors outside the job, and in particular the stability of the pilot’s home life and marital relationship, significantly influence the pilot’s level of stress and coping ability (Cooper & Sloan 1985; Karlins et al. 1989). As many GBRP are separated from family for the duration of their tour of duty, concern over non-work related issues may add to the stress experienced by marine pilots.
4.9 Summary
In summary, there are many aspects of marine pilotage work which can potentially induce stress. As a consequence, the psychophysiological state of the pilot may be reduced to such a level that fatigue is experienced and performance, health and well-being are impaired. Personal characteristics and the effectiveness of the pilot’s support network are important moderating factors in determining how much stress pilots experience.