Improving the watch standing schedules of two US Navy watch floors in the San Diego area

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Authors
Shattuck, Nita Lewis
Matsangas, Panagiotis
McClernon, Christopher K.
Subjects
Watchstanding schedules
human performance
sleep deprivation
fatigue
sleep quality
Advisors
Date of Issue
2023-12
Date
December 2023
Publisher
Monterey, California. Naval Postgraduate School
Language
Abstract
The overarching aim of this project was to assess the work and rest schedules of shift workers on information warfare (IW) watchfloors with the ultimate goal of improving the quality of life and performance. Two US Navy watchfloors in the San Diego area were evaluated. The specific study objectives were to document the watchbills used, assess the strengths and weaknesses of the watchbills, estimate the overall readiness of the watchstanders participating in the study, and develop watchstanding and fatigue mitigation recommendations tailored to the two watchfloors in order to maximize watchstanders’ readiness. Data were collected between February and May 2023 (N=82 participants; 62.2% males, median age of 27 years ranging from 19 to 54 years, 85.4% enlisted). Using a quasi-experimental longitudinal approach, volunteer participants wore ŌURA rings and completed a series of standardized and validated questionnaires at the beginning and end of the study period. The body weight of 57.3% of participants was above normal (i.e., BMI>25), 97.6% reported consuming caffeinated beverages, 24.4% used nicotine products, and 85.6% had a regular exercise routine. Participants slept 6.71 hours per day (median); 62.3% of participants slept less than 7 hours per day and 14.5% slept less than 6 hours per day. Approximately 84% of the participants reported taking a nap during the data collection period; however, habitual napping was not highly prevalent with 25.5% of participants napping once every 10 days, and only 3.64% napping once every 4 days. Using standardized self-report assessment tools, 88.9% of the participants were classified as poor sleepers, 30.5% reported symptoms of excessive daytime sleepiness, 20.7% reported symptoms of insomnia, while 20.7% of the participants had all three conditions. Based on responses on the Profile of Mood States scale, the mood of Sailors on the two watchfloors was generally worse than normal adult populations with 74.1% of our participants scoring worse than the 50th percentile for total mood disturbance, 79.0% on the tension-anxiety subscale, 80.3% on the vigor-activity subscale, 72.8% on the fatigue subscale, and 80.3% on the confusion-bewilderment subscale. Compared to a sample of 568 Sailors underway on USN ships, the mood of the Sailors on the two watchfloors was worse in terms of tension-anxiety and confusion-bewilderment, but was equivalent for depression, anger-hostility, vigor-activity, fatigue, and total mood disturbance. One of the watchfloors being studied used a rotating 4-section/12-hour-shift watchbill with watchstanders rotating between day and night shifts every 30 days. The second watchfloor used a rotating 6-section/8-hour-shift watchbill with watchstanders rotating between days, eves, and mids every 30 days. Overall, our findings suggest that the 6-section/8-hour-shift watchbill is in general preferable to the 4-section/12-hour-shift watchbill. Based on the data collected from the two watchfloors, the predicted effectiveness of the two watchbills as assessed by the SAFTE/FAST model, the background literature on shiftwork, and the other studies conducted by the NPS Crew Endurance Team in military settings, we developed general guidelines and recommendations for fatigue mitigation.
Type
Technical Report
Description
Series/Report No
Department
Operations Research (OR)
Organization
Naval Postgraduate School
Identifiers
NPS Report Number
NPS-OR-23-008
Sponsors
Naval Postgraduate School, Naval Research Program; Naval Information Forces
Funder
Naval Postgraduate School, Naval Research Program (PE 0605853N/2098)
Format
91 p.
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.
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