Sleep and Performance in Operational Maritime Environments:

Working Conditions at Sea

Nita Lewis Shattuck, Ph.D. Panagiotis Matsangas, Ph.D.

Operations Research Department

Agenda

Life as a Sailor in the US Navy

Working conditions at sea

Factors affecting sleep

Fatigue countermeasures including guidelines for well-rested crews

US Navy Personnel

Officers 17%

Enlisted 83%

Male 84%

Female 16%

0%

10%

20%

30%

40%

50%

60%

25 or younger

26 to 30 31 to 35 36 to 40 40 or older

Officers

Enlisted

Life at sea!

Life at sea!

Life at sea!

Life at sea!

Life at sea!

Life at sea!

The Big Gray Elephant

“Fatigue is so prevalent and such a part of our culture that we scarcely see or recognize it. It’s the big gray elephant we muscle out of the cockpit when we fly, step around when we enter the bridge, and push aside when we peer into the periscope.”

CAPT Nick Davenport, USN, MC (ret)

Former Command Physician

US Naval Safety Center

Factors Leading to Disrupted Sleep at Sea

Psychological-Pharmacological

Stress, anxious thoughts

Harassment from leadership,

crewmembers

Caffeine, energy drinks

Nicotine

Environmental

Ship motion

External noise

Smells

Temperature

Berthing Compartment Habitability

Lack of privacy

Internal noise

Temperature

Light in the compartment

Organizational

Irregular sleep schedules

Watch schedules

Long work hours

Duties/operational

commitments

Fatigue and Sleep Studies NPS 2001-2015

Note 1: Blue bars indicate actigraphic sleep, gold bars are self-reported sleep Note 2: Number centered on each bar refers to study sample size Note 3: Horizontal lines indicate one standard deviation

n=33

n=167

n=21

n=70

n=41

n=19

n=25

n=24

n=29

n=21

n=25

n=42

n=11

n=34

n=19

n=19

n=70

n=117

0 2 4 6 8 10

Operation Enduring Freedom (USS JOHN C. STENNIS - CVN 74)

Various operations (SSN / SSBN)

GOMEX 05-1 (HSV 2 SWIFT)

RIMPAC 2008 (USS LAKE ERIE - CG 70 / USS PORT ROYAL - CG 73)

Sea trials (USS HENRY M. JACKSON - SSBN 730)

Sea trials (HSV 2 SWIFT)

Predeployment training (USS CHUNG HOON - DDG 93)

Predeployment training (USS RENTZ - FFG 46)

Rough Water Trials (LCS 1) - 2011/01-02 - Lower SS (<4)

Rough Water Trials (LCS 1) - 2011/01-02 - Higher SS (>=4)

Calm Water Trials (LCS 2) - 2013/05

Independent steaming in Arabian Golf (DDG 109) - 3/9 watch schedule

Independent steaming in Arabian Golf (DDG 109) - 6/6 watch schedule

Training exercise USS BENFOLD (DDG 65) - modified 6/18 watch

Rough Water Trials (LCS 2) - 2014/01-02 - Lower SS (<=4)

Rough Water Trials (LCS 2) - 2014/01-02 - Higher SS (5-6)

Training (USS NIMITZ - CVN 68) - 5/10 watch schedule

Sea trials (USS NIMITZ - CVN 68) - 3/9 watch schedule

Daily Sleep [hrs]

Sleep - Naval Operations

Factors  affec+ng  sleep    USS  Nimitz  –  RX  Dept  on  5/10  

0%   20%   40%   60%   80%   100%  

Ship's  mo*on  

Stress/Anxiety/Thoughts  

Light  

Bedding  condi*ons  

Temperature  

Noise  

Not  enough  *me  to  sleep  

Percentage  of  respondents  repor*ng  these  issues    

Yes   No  

Noise  from  other  people  28%  

Noise  from  

inside  the  berthing  compartm

ent  

Noise  from  

outside  the  

berthing  compartm

Noise  from  1MC  

15%  

Noise  

Bed  size  27%  

MaMress  35%  

Pillow  10%  

Curtain  8%  

Odors  20%  

Berthing  Issues  

Shiftwork in U.S. Navy Watch

schedules

Circadian (24 hour)

2-section

6/6

12/12

3-section

4/8

8/16

4-section

3/9

6/18

Non-Circadian

3-section

5/10

6/12

4-section

5/15

Workday includes duties other than watchstanding. Other watchbills may be implemented by the command

Operational studies of work/rest patterns of USN crews

Actigram of a typical sleep pattern at sea

PVT reaction times on different USN watch schedules

100

200

300

400

500

RX on 5-on/10-off

(n=39)

RX on 3-on/9-off

(n=83)

3-on/9-off (n=24)

Modified 6-on/18-off

(n=34)

OPS with 6-on/6-off

(n=9)

Mea

n R

T (m

s)

Mean RT, [ms]

Fastest 10% RT, [ms]

Errors (PVT lapses + False Starts) on different USN watch schedules

0

10

20

30

40

50

60

RX on 5-on/10-off

(n=39)

RX on 3-on/9-off

(n=83)

3-on/9-off (n=24)

Modified 6-on/18-off

(n=34)

OPS with 6-on/6-off

(n=9)

Perc

enta

ge p

er tr

ial

Lapses 500ms+FS, %

Lapses 355ms+FS, %

Sleep and caffeine/energy drinks USS Nimitz survey (N=767)

88% consume coffee, tea, caffeinated soft drinks, or energy drinks

36% consume energy drinks

0%

10%

20%

30%

40%

50%

60%

Coffee Caffeinated soft drinks

Energy drinks

Tea

Con

sum

ptio

n of

caf

fein

ated

be

vera

ges

% o

f res

pons

es

16% of the participants

5

6

7

8

< 1,270 mg ≥ 1,270 mg

Rep

orte

d Sl

eep

Am

ount

(hou

rs)

Estimated caffeine intake per week

1,270 mg equivalent to 180 mg daily

Consequences of poor sleep practices

Short-term effects •  Performance

decrements (reaction time, errors)

•  Decreased vigilance •  Inconsistent logical

reasoning •  Reduced short-term

memory •  Negative mood •  Increased risk of

injury and death •  Increase in stress

hormone production

Intermediate effects •  Loss of motivation

and morale •  Poor memory •  Longer time to train •  Decreased immunity •  Caffeine addiction •  Elevated mishap

rates •  Failure to accomplish

mission

Long-term effects •  Circadian scarring •  Metabolic disorders •  Chronic disease due

to long-term sleep debt

•  Inability to recruit and retain Sailors

Intervention Approaches Collect data to demonstrate relationship between sleep and

performance

Provide education and training resources

Best (and worst) practices and guidance

http://my.nps.edu/web/crewendurance

Why bother?

We have a large population of shiftworkers in the US Navy.

What we do in terms of scheduling their work and rest makes a huge difference in their quality of life -- both now and in the future.

Questions?

Contact information:

Nita Lewis Shattuck, Ph.D.

(831)656-2281

nlshattu@nps.edu 23

Special thanks to Dr. Panagiotis Matsangas, Dr. Lauren Waggoner, and multiple Naval Postgraduate School graduate students for their help in collecting and analyzing the data from these studies. Acknowledgements: The work has been supported by the Advanced Medical Development Program of the Naval Health Research Center, OPNAV N1 Naval Studies Program, the Office of Naval Research, and the USN 21st Century Sailor Office.

A Population of Shiftworkers and Poor Sleepers

The US military indoctrinates healthy US adults into a culture of sleep deprivation that persists throughout their careers.

Like other shiftworkers, members of the military frequently exhibit “circadian scarring” and often engage in “binge sleeping.”

Based upon scientific findings from research on both civilian and military populations, these sleep practices are associated with decreased performance and long term health consequences.

25

Note: Brown University data were collected on the Class of 1992 (Fall 1988 – Spring 1990 using self-report. USMA data were collected using actigraphy on the

Class of 2007 Fall 2003 – Spring 2005 (Miller, Shattuck, & Matsangas, 2010).

6:45 6:52 7:04 6:59

4:50 5:06 5:17 5:12

0:00

1:12

2:24

3:36

4:48

6:00

7:12

8:24

1st Sem 2nd Sem 3rd Sem 4th Sem

Brown USMA

Sleep debt begins on Day One of Military Service… A Comparison of Sleep between Brown University

Students and Cadets at USMA, West Point

42%

8%

27%

21% 21%

31%

9%

33%

2%

9%

0% 5%

10% 15% 20% 25% 30% 35% 40% 45%

Mysliwiec et al. (2012) 725 Army, Navy, Air Force

Krueger & Friedman (2009) 10,441 civilians

< 5

6

7

8

> 9

…and continues throughout their careers

18

Even non-deployed military sleep fewer hours than civilians

Average Hours of Sleep per Day

26

Recommendations based on studies over 15 year period

Give crewmembers opportunity to sleep at same time each day.

If 4 section watch can be supported, consider either 3-9 or fixed 6-18 schedules.

If 3 section watch, consider 4-8 watchstanding schedule.

Provide protected sleep periods for night watchstanders/day sleepers.

Naps are helpful, especially if not too close to major sleep period.

Rotations should be forward, lengthening the work day rather than shortening it.

Characteristics of sleep at sea

Sleep deprivation due to extended workdays

Major sleep episode – often does not exist

Split sleep – napping may or may not happen

Fragmented sleep – poor quality

Sleep at different times of the day

Poor berthing compartment – habitability

Caffeine consumption – esp. energy drinks

Motion-induced disturbances

Factors  affec+ng  sleep    USS  Nimitz  –  RX  Dept  on  5/10  and  3/9  

0%   20%   40%   60%   80%   100%  

5/10  

3/9  

5/10  

3/9  

5/10  

3/9  

5/10  

3/9  

5/10  

3/9  

5/10  

3/9  

5/10  

3/9  

Ship's  

mo+

on  

Stress/  

anxiety/  

thou

ghts  

Light  

Bedd

ing  

cond

i+on

s  Tempe

rat

ure  

Noise  

Not  

enou

gh  

+me  to  

sleep

 

Percentage  of  respondents  repor*ng  these  issues    

Yes   No  

0%   20%   40%   60%   80%   100%  

5/10  

3/9  

5/10  

3/9  

5/10  

3/9  

5/10  

3/9  

Noise  

from

 1MC  

Noise  

from

 ou

tside  

the  

berthing  

compartm

ent  

Noise  

from

 insid

e  the  

berthing  

compartm

ent  

Noise  

from

 othe

r  pe

ople  

Percentage  of  respondents  repor*ng  these  issues  

0%   10%   20%   30%   40%   50%   60%   70%   80%   90%  100%  

5/10  3/9  5/10  3/9  5/10  3/9  5/10  3/9  5/10  3/9  

Bedd

ing  

cond

i+o

ns:  

curtai

n  

Bedd

ing  

cond

i+o

ns:  

pillow  Be

ddi

ng  

cond

i+o

ns:  

odors  Be

ddi

ng  

cond

i+o

ns:  

bed  

size  

Bedd

ing  

cond

i+o

ns:  

maM

ress  

Percentage  of  respondents  repor*ng  these    issues  

On average, how many hours did you sleep per night in the past 30 days?

Frequency Percent 3 hours or less 2,401 2 4 hours 8,952 8 5 hours 21,386 20 6 hours 35,521 33 7 hours 25,263 24 8 hours 12,264 11 9 hours 815 1 10 or more hours 992 1 Total 107,594 100

30

Sleep Question from DEOCS (2013)

63% get 6 hours or less

sleep per night

Defense Equal Opportunity Climate Survey (DEOCS) Slide courtesy of Geoff Patrissi, NPRST

Guiding principles developed for ADM Richardson (NR)

Focus on maintaining alert and engaged Sailors

Learn and understand the effects of good sleep practices

Use the 24-hour circadian rhythm to set the foundation

Build a stable daily schedule including the watch bill that maximizes sleep opportunities at the same time each day

One size does not fit all -- consider tradeoffs

Get supporting analysis on your schedule before you make a final decision

6-month assessment of CO sleep during deployment

0

1

2

3

4

5

6

7

8

9

10

6/24

6/

29

7/4

7/9

7/14

7/

19

7/24

7/

29

8/3

8/8

8/13

8/

18

8/23

8/

28

9/2

9/7

9/12

9/

17

9/22

9/

27

10/2

10

/7

10/1

2 10

/17

10/2

2 10

/27

11/1

11

/6

11/1

1 11

/16

11/2

1 11

/26

Dai

ly S

leep

in h

ours

Day

Major Night Sleep Naps Average daily sleep

Benghazi attack 11 SEPT 2012

5.19 hrs

•  Actigram for entire 6-month deployment •  Sleep patterns of a 39-year old commanding officer of a USN Destroyer while

the ship was forward-deployed to Middle East •  Time included Benghazi event •  Average daily sleep: 5.19±1.25 hr

–  17% of deployment Sleep < 4hrs –  Sleep > 8hrs for only 2% of time

Crew Endurance Website

http://my.nps.edu/web/crewendurance