Sleep patterns, mood, psychomotor vigilance performance, and command resilience of watchstanders on the “five and dime” watchbill

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Authors
Shattuck, Nita Lewis
Matsangas, Panagiotis
Powley, Edward H.
Subjects
Watch schedules
sleep
psychomotor vigilance performance
command resilience
Advisors
Date of Issue
2015-02
Date
February 2015
Publisher
Monterey, California. Naval Postgraduate School
Language
Abstract
This study assesses crew rest and sleep patterns, psychomotor vigilance performance, work demands and rest opportunities, organization commitment, and psychological safety and command resilience of Sailors in the Reactor Department on USS Nimitz (CVN 68) (N = 77) working the 5hrs-on/10hrs-off (5/10) watchstanding schedule. Although crewmembers on the 5/10 received approximately seven hours of sleep per day, they reported experiencing excessive fatigue and dissatisfaction with the schedule. This contradiction is best explained by examining sleep and rest periods over a 72-hour period, during which a crewmember sleeps at three distinctly different time periods each day. On the first day of the cycle, the Sailor typically receives an early-terminated 4-hour sleep episode followed by two periods of sustained wakefulness, 22 and 20 hours. During these periods, daytime napping only partially ameliorates the fatigue and sleep debt accrued during these periods of sustained wakefulness. Given this pattern, it is not surprising that at the end of the underway phase, the crewmembers’ moods had worsened significantly compared to moods at the beginning of the underway period. Psychomotor vigilance performance in the 5/10 is comparable to the performance of Sailors on the 6hrs-on/6hrs-off (6/6) schedule. It is significantly degraded compared to Sailors on the modified 6hrs-on/18hrs-off (6/18) and the 3hrs-on/9hrs-off (3/9) schedules. Specifically, the 5/10 had 21.4% slower PVT reaction times, and 71.5% more lapses plus false starts than the 3/9. Our findings suggest that the 5/10 watch, combined with other work duties, leads to poor sleep hygiene. Crewmembers on the 5/10 suffer from sustained wakefulness because of extended workdays and circadian-misaligned sleep times. In general, the self-reported survey results suggest low degrees of resilience, psychological commitment to the organization, and psychological safety. In terms of organizational commitment, participants report that they do not talk positively about their department and do not view their department as inspiring performance. Conversely, Sailors report a high degree of willingness to put in effort beyond expectations, even though overall results indicate low psychological attachment to the unit as a place for working and completing work tasks. Results also show low levels of psychological safety.
Type
Technical Report
Description
Prepared for: Twenty-First Century Sailor Office, N 171; 5720 Integrity Drive, Millington, TN 38055 and Advanced Medical Development Program; Naval Medical Research Center; 503 Robert Grant Avenue, Silver Spring, MD 20910
Series/Report No
Department
Operations Research
Organization
Identifiers
NPS Report Number
NPS-OR-15-003
Sponsors
Funder
Twenty-First Century Sailor Office (N 171), 5720 Integrity Drive, Millington, TN 38055 and the Advanced Medical Development Office of Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD 20910.
Format
Citation
Distribution Statement
Approved for public release; distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.