This study aimed to assess stress and strain as well as the work ability of maritime pilots by using standardized questionnaires, taking into account the different rotation systems. In 2015 Main and Chambers published a review about fatigue and coping strategies in maritime pilotage. In the time frame from 1977 to 2014, they identified only 18 studies and concluded that most of these available studies were rather old and often relied on very small study populations [5]. The present study is the first one dealing with stress and strain as well as the work ability of maritime pilots by using standardized questionnaires.
Within the past decades, pilotage has undergone extensive development: firstly, the working conditions of the pilots have changed, e. g. due to the growing size of container ships, higher technical requirements, or newly formed training paths due to stagnating numbers of newcomers [23]. Secondly, the awareness of work-life balance has changed, which may lead to a decrease in job satisfaction [24]. These developments should be taken into consideration when assessing the current job-related psychophysical stress and strain of pilots. This also highlights the finding that the old available studies are not suitable for judging the current circumstances in the pilots’ profession and there is a need to gain new knowledge.
In the present study, most pilots evaluated irregular working hours including night work as the main stressor of their job resulting in unplannable family time. On the one hand, a majority of pilots (especially from the 4-month ROS) experienced relevant psychological demands in their workplace and stated that they were less often full of hope about the future. This may indicate their subjective perception of particularly high work-related mental stress. On the other hand, more than 80% of the pilots stated having regularly neglected their private obligations. This suggests that many pilots had difficulties in reconciling work and private requirements, which can be seen as a sign of disturbed work-life balance. The well-known finding that one of the major stress factors for seafarers on board is the long-term separation from their family and the loneliness on the high seas should emphasize the importance of the family for pilots [12, 25]. Maritime captains normally have contracts for at least 3–4 months at a stretch; their urgent need for more time for the family after a life at sea as a captain is an important reason for an occupational change in favor of a career as a pilot [26, 27].
Even though a lot of pilots mentioned their subjective stress due to difficulties in reconciling working life and family life, the stress level varied amongst the ROS. Pilots from the 4-month ROS experienced insufficiently predictable free time and long operation times at a stretch significantly more often as main stressors. This is in line with the observation within the OECD study “Employment Outlook” [28], which concludes that unpredictable working hours correlate with lower family satisfaction. Besides their higher mental load through long-term assignments, this could possibly lead to a higher dissatisfaction with their work situation among pilots with 4-month ROS compared to their colleagues. Pilots from the 1-week ROS stated working under wet and cold conditions more often as the main stressor as they need to work outside during berthing maneuvers. Moreover, the fact that the pilots of the 1-week ROS tended to more often have children younger than 6 years and a working partner may indicate better reconciliation of work and family in this pilot group.
High stress load in the workplace can lead to psychophysical exhaustion and fatigue [29]. The present study also examined the occurrence of daily sleepiness. Higher results for daily sleepiness were found among pilots in comparison to professional groups with a higher risk of fatigue (e. g. truck and bus drivers or shift worker) [30,31,32]. Although significantly more pilots in 4-months ROS experienced psychological demands of the work, no difference was observed in the daily sleepiness between the employees of the two different ROS. Ferguson et al. [10] already described the positive effects of short, irregular sleep opportunities at sea on the alertness of marine pilots. For that reason, it is recommended to counteract fatigue through short naps in cases where pilots are waiting at the pilot station for the next assignment.
Generally, psychophysical exhaustion can increase the risk of maritime disasters or accidents [33, 34]. In this study, 4-month ROS pilots distinctly more often reported having had occupational accidents with severe personal injuries that may be explained by their pilotage district in the environmentally rougher coastal area. Furthermore, both boarding and leaving the vessel require climbing on the pilot ladder at the outer wall of the ship, which is physically stressful and potentially hazardous. In contrast, significantly more 1-week ROS pilots stated having had vessel damage. This was expected since grounding is a major risk within the harbor basins.
Specific causes of occupational accidents and vessel damage have not been further investigated in this study. According to a Belgian study, the accidents during pilotage were mostly due to the harsh environment (wind speed, state of the sea, poor visibility); Human factors accounted for 11.7% (stress, sleep deprivation, bad physical condition), with only 2.9% of the accidents caused by not enough sleep [11]. In light of the high percentage of daily sleepiness among the pilots examined, further research is of high importance to investigate the extent to which human factors are causal to occupational accidents and maritime disasters during pilotage.
Moreover, due to the unpredictability of the assignments and the night work, an irregular and possibly not healthy diet is typical for pilots. This hypothesis adds support to the present study as more than 70% of the study sample was classified as overweight. This is in line with the results of the review from Main and Chambers [5] on the factors affecting maritime pilots’ health and well-being. The “healthy worker effect” needs to be considered to ensure that there is no selection bias. As pilots are required to have regular medical check-ups concerning their health ability to work at sea, the study population should have a better general state of health in comparison to the general population [35].
In contrast, Main and Chambers [5] observed that pilots are at a significantly higher risk of health impairment than the general population; particularly cardiovascular diseases, mental illnesses (sleep disorders, depression, burnout), and accidents were frequently found in the 18 studies observed. Among pilots examined in this study, the most current diseases were related to the musculoskeletal system at just below 35%, followed by cardiovascular diseases at 25%, and accidental injuries at just under 20% − in similar frequency between the two ROS.
An unfavorable lifestyle and obesity have also been repeatedly discussed as a major risk factor for cardiovascular diseases in seafaring populations. Several studies have consistently shown that obesity, smoking, high lipid levels in the blood, lack of exercise, and unhealthy eating habits are much more common in seafarers than in the general population [3, 36, 37]. In the present study, particularly overweight was more prominent among pilots compared to that of the male German general population (73.1%. vs. 62.1% [38]). Furthermore, no differences in lifestyle factors were found between the two ROS. Generally, it is assumed that job-related stress is associated with an unhealthy lifestyle [39]. Assuming higher psychological demands of the work among pilots of the 4-month ROS, such association, however, cannot be shown in this study.
To assess the stress and strain of maritime occupations, a pilot-specific questionnaire was developed based on an established seafaring-specific questionnaire [12]. This was about seafarers’ stress and strain and has previously been used several times in various maritime studies [13, 14]. The questionnaire of this study was created by the heads of some pilots’ associations and several pilots. Finally, it was tested and improved in a pilot study. In the online portal, all pilots had the opportunity to comment and to add some further aspects in free text. Overall, a sufficiently high representativeness was assumed for the assessment of the pilots’ stress and strain, since several pilots answered the above-mentioned maritime specific questionnaire and they had the opportunity to add important aspects within the supplementary free text.
According to the WAI in this study, the work ability of pilots showed no differences in comparison to those of other land-based study populations (teachers, office workers, executives) [40]. In addition, no significant differences in the work ability were observed between the pilots of the two different ROS.
In total, this study revealed, on the one hand, more often job-related mental demands, disturbed work-life balance and longer operation times at a stretch among 4-month ROS, indicating significantly higher job stress. On the other hand, this higher stress level does not lead to more sleepiness or reduced work ability in this occupational group. This suggests that the pilots of the 4-month ROS might be highly adapted to their working situation aboard. In view of the pilots’ higher average age of 48.5 years, it can be assumed that their job activity was carried out on average for at least 15 years. Moreover, since a switch between the two ROS almost never occurs, the pilots are not familiar with the alternative rotation system and have likely adjusted to their working conditions, so that, despite an increased work-related stress level in the 4-month ROS, there is no increased risk of daytime sleepiness or inability to work.
Another explanation for the missing correlation could be that the pilots with the 4-month ROS (who were obviously much more often stressed) more frequently downplayed both their sleepiness and their inability to work in the sense of social desirability. Furthermore, according to the assessment of many pilots, the working conditions for a 4-month deployment are regarded as given and unchangeable. Thus, it can be assumed that these pilots as freelancers perceive safety-related restrictions due to increased sleepiness or inability to work as a threat to their existence. Accordingly, the examiners repeatedly observed emotional discussions about the need to change the ROS, especially among pilots with the 4-month ROS. In addition, it cannot be excluded that many pilots with severe sleepiness or inability to work − phenomena that are mainly suspected in the 4-month ROS − did not take part in this study. As a result, these pilots could be underrepresented in this survey in the sense of a selection bias.
Strengths and weaknesses of the study
As a limitation, the present study focused on sea, canal and port pilots in Germany. It is yet unclear how far the results are transferable to other international pilot systems. Furthermore, the freelancer status of pilots has to be taken into consideration as it makes it scarcely possible to compare them with other land-based occupational groups. Additionally, only a small group of 1-week ROS pilots were present in this study. However, since only the port pilots’ associations practice the latter ROS and there are far less port pilots than river or sea pilots, a considerably smaller number of 1-week ROS was expected. The proportion of participants was similar in each ROS. The demographic data of the participating pilots were also not different from those of the total pilot group, indicating that no bias or underrepresentation was present.
The participation rate of 46.9% is usual in online surveys, and a selection bias cannot be ruled out. There are no current studies on the pilots’ working conditions, so there is no experience with the willingness of this professional group to participate in studies. Finally, the questionnaire used on stress and strain was not standardized as no suitable instrument is available to assess the pilot-specific work situation. Thus, a pilot specific questionnaire was developed based on a repeatedly used questionnaire about the seafarers’ stress and strain and on the statements by several pilots. As in this study no pilot used the opportunity to add an additional stress or strain factor as free text to the predetermined list, this questionnaire is regarded as complete and representative for assessing the pilots’ stress and strain – especially in light of the satisfying internal consistency with a Cronbach’s alpha of 0.76.
