Hours of work at sea: watchkeeping schedules, circadian rhythms and efficiency

Wp, Colquhoun

doi:10.1080/00140138508963178

Cited by 28 publications

(15 citation statements)

References 12 publications

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“…This conclusion aligns with previous research showing that rotating watch schedules inevitably produce fragmented sleep and disrupt physiological rhythms (Colquhoun et al 1968;Colquhoun 1985). Watchstanding schedules that take human physiology into account may lead to better performance in the operational environment (Miller 2006).…”

Section: Discussionsupporting

confidence: 78%

“…Watchstanding schedules that take human physiology into account may lead to better performance in the operational environment (Miller 2006). For example, shift schedules leading to circadian-aligned 24-h day and allowing watchstanders to sleep at the same time every day are more tolerable from a circadian rhythm perspective (Colquhoun et al 1968;Colquhoun 1985). Lastly, we should emphasise the need to educate crewmembers on healthy sleep habits.…”

Section: Discussionmentioning

confidence: 99%

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Operational assessment of the 5-h on/10-h off watchstanding schedule on a US Navy ship: sleep patterns, mood and psychomotor vigilance performance of crewmembers in the nuclear reactor department

Shattuck

Matsangas

2015

Ergonomics

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We assessed sleep patterns, psychomotor vigilance performance, work demands and mood of 77 crewmembers of USS NIMITZ (CVN-68) on the rotating 5-h on/10-h off (5/10) watchstanding schedule. Within the 3-day cycle of the 5/10, sleep occurred at distinctly different times each day. On two of these days, sailors typically received only brief, 4-h sleep episodes followed by periods of sustained wakefulness (approximately 22 and 20 h). Crewmembers received approximately seven hours of sleep daily, but reported excessive fatigue and dissatisfaction with their schedule. Crewmembers' mood worsened significantly over the course of the underway phase. Psychomotor vigilance performance (reaction times, lapses) was significantly degraded compared to performance when working circadian-aligned schedules. Overall, standing watch on the 5/10 schedule, combined with other work duties, resulted in poor sleep hygiene. Crewmembers on the 5/10 experienced periodic bouts of sustained wakefulness and accrued a significant sleep debt due to extended workdays and circadian-misaligned sleep. Practitioner summary:We assessed crewmembers' sleep patterns, psychomotor vigilance performance and work demands when working a rotating 5-h on/10-h off (5/10) watchstanding schedule. The 5/10, combined with other work duties, resulted in poor sleep hygiene. Crewmembers experienced periodic bouts of sustained wakefulness and accrued a significant sleep debt due to extended workdays and circadian-misaligned sleep.

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Section: Discussionsupporting

confidence: 78%

Section: Discussionmentioning

confidence: 99%

Operational assessment of the 5-h on/10-h off watchstanding schedule on a US Navy ship: sleep patterns, mood and psychomotor vigilance performance of crewmembers in the nuclear reactor department

Shattuck

Matsangas

2015

Ergonomics

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“…Several countermeasures to the difficulties incurred in shift work have been suggested. A frequently used approach is one involving the strategic planning of naps in order to improve alertness and performance [91][92][93][94][95][96] . This approach is efficient in rapidly alleviating sleepiness at night, however it can negatively impact the quality of the subsequent sleep episode while its beneficial effects may be undermined by the phenomenon of sleep inertia.…”

mentioning

confidence: 99%

Light Treatment and Circadian Adaptation to Shift Work

Boivin

James

2005

Ind Health

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Work at unconventional hours can have both long and short term consequences. Shift workers are often required to perform their duties at times that are not favoured by the body's endogenous clock, or circadian pacemaker. A typical night shift worker, for example, may report reductions in alertness and performance during shifts, or significant difficulty attaining sleep of recuperative value in the day, all the while being more likely to develop health complications. The study of circadian physiology has significantly contributed to our current ability to aid the shift worker deal with atypical schedules. We discuss the usefulness of light treatment as a countermeasure for maladaptation to atypical work schedules.

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“…However, in the long run, this objective is less important for watchstanders on a long cruise than the benefits to be accrued from the fixed schedule.) Colquhoun, in fact, recommended using a 1-in-3, 8-h fixed watch schedule (Colquhoun, et al, 1978;Colquhoun, 1985). Alternatively, he recommended a modification of Kleitman's close watch schedule that used fixed work and rest periods.…”

Section: Other Alernativesmentioning

confidence: 99%

“…On the basis of these observations and parallel observations of body temperature cycles in four officers standing fixed, 8-h watches, Colquhoun et al (1978) recommended using a 1-in-3, 8-h fixed watch schedule (also, see the review by Colquhoun, 1985). Alternatively, they recommended a modification of the schedule suggested by Nathaniel Kleitman in 1949 in which the 8 hours of watch are completed within a fixed, 12-h period (close watch).…”

Section: Scientific Rationalementioning

confidence: 99%