Navy experts searching for ways to keep the fleet well-rested now are focusing on sailors working the night shift. Here, Chief Aviation Boatswain's Mate (Handling) Stanley Bollinger, a night aircraft handling officer on the carrier Carl Vinson, makes an announcement during a 2011 deployment in the Indian Ocean. (MC3 Christopher K. Hwang/Navy)
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Nita Shattuck, a human performance expert at the Naval Postgraduate School in Monterey, Calif., has spent 12 years studying how sleep affects performance in the fleet. With the help of the officers who are her researchers, Shattuck is boosting awareness of the risks of inadequate rest and encouraging the adoption of watch and work shifts that conform to the human body’s normal 24-hour clock.
Her current research projects in the fleet:
■The San Diego-based ship plans to try a three-hours-on, nine-hours-off watch rotation for underway watches. This four-section rotation offers two benefits: Shorter watches that keep watchstanders more alert and conformance to the 24-hour circadian rhythm.
The crew of the destroyer Jason Dunham tried the 3/9 and generally preferred it to the so-called “five and dime” rotation: five hours on watch, 10 hours off. The Benfold crew experimented with six-on, 18-off rotations on its 2012 deployment.
■Researchers have begun collecting watchstander performance data and alertness levels aboard the deployed carrier, where some crew members are wearing watches that track their sleep. Shattuck said the crew of the Nimitz, now patrolling the Red Sea, is only the second carrier crew she’s studied.
Littoral combat ships
■Shattuck’s team has received funding to study crew work and rest aboard both types of littoral combat ships, which depend on 50-person core crews for all their watchstanding and maintenance tasks.
YOUR SAY: Any sleep tips for the night crew or suggested study areas for Navy sleep experts? Send them to firstname.lastname@example.org.
As ships continue to experiment with watchbills that improve sailors’ sleep, one of the Navy’s foremost performance experts is warning about a new front in the Navy’s fight against fatigue: shift work.
Researchers are increasingly concerned that those who stand night duty long-term get less sleep and are susceptible to health risks down the road, findings that could affect the thousands of sailors who routinely pull late-night duties in ships and squadrons.
“All the evidence on shift work indicates that if you sleep during the day, when other people would be working, the quality of your sleep is less,” said Nita Shattuck, a professor at the Naval Postgraduate School who is one of the Navy’s foremost experts on fatigue and human performance. “So you have poorer quality of sleep and they estimate that, in general, it’s two-thirds of the amount of sleep you would get for a nighttime” period.
The Navy is not about to cancel night shifts, but Shattuck and some fleet leaders are looking for ways to improve sailors’ sleep, especially for night crews. Here are some fixes they’ve come up with:
Berthing by shift. Reorganize berthing compartments so that everyone in a given compartment is on the same shift, thereby reducing the number of noises, talking and lights, which disturb sleep.
Quiet ship. Reduce the number of general announcements to the bare minimum and only allow them during times when everyone is awake. Ask sailors to remain quiet around berthing compartments where shipmates are resting.
Thicker curtains. Block out the biggest sleep disruptor: light. Seeing a bright light makes it harder to get back to sleep, studies have shown. The best defense against this are the curtains alongside a sailor’s rack. The destroyer Benfold is considering thicker material to keep out light and even muffle sound.
Shattuck and many others worry that chronic sleepiness is a fleetwide epidemic that harms health and morale and leads to accidents. But their campaign must contend with skepticism in branches like the surface and sub fleets, which have long viewed sleeplessness as a badge of honor — a sign that a sailor was getting the job done.
Fighting sleep foes
The handling of fatigue remains uneven across the fleet. Aircrews won’t fly unless they’ve slept enough, but sleep is not a prerequisite for a shipboard watchstander. And submariners typically live artificial 18-hour days underway, sometimes for months on end.
Shattuck and her postgraduate students are continuing to study crew rest and are testing the feasibility of better watch rotations aboard different classes of ship, with the help of commanding officers. A mounting body of evidence suggests that sailors are more alert when they conform to a 24-hour day, where they sleep at the same time daily.
The goal of the researchers is to persuade more squadrons, ships and subs to adopt watchbills that follow the body’s natural 24-hour clock: rotations like four hours on, eight hours off, or three on, nine off. Both allow sailors to get up at the same time daily and give them enough time off to get the deep slumber needed to reset their bodies and stay alert.
Those efforts got a big boost in May from the heads of the surface Navy, who called upon ship COs to embrace the concept of crew rest and to experiment with circadian watch rotations. It remains unclear whether the Navy’s other type commanders will similarly endorse this, but Shattuck is moving forward with other studies in the hopes of persuading more leaders to get serious about rest.
One of her focuses is night crews. A 2013 study found that those who worked night shifts for a long time sleep more fitfully than daytime workers even years later, a condition that can lead to other health issues. That builds on research that night crews are more fatigued and more susceptible to mental health issues and even cancer.
But this goes beyond health, proponents say. Having well-rested sailors boosts combat effectiveness. The Coast Guard and naval aviation recognize this and have firm crew rest rules. Shattuck said the rest of the Navy could also learn from Navy SEALs, who typically keep sleeping areas, like tents, quiet and dark for night crews.
“That’s probably the best that we can do,” Shattuck said in an Oct. 16 phone interview. She cited recent studies that found light, whether from the sun or an open refrigerator door, disrupts the body’s production of the hormone that induces sleep, making it much harder to go back to sleep. “Even that tiny amount of light in the middle of the night ... will suppress your melatonin, which is your sleep drug.”
That’s where the curtains come in. Shattuck is working with the Benfold to find and test curtains that better keep out light; a thicker material might also dampen sound.
One of the foremost noise conduits are vents at the bottom of a berthing door. Commands like the Seawolf-class submarine Jimmy Carter are exploring ways to dampen the sound that comes through berthing doors and to keep the passageways quiet around berthing areas.
Indeed, one of the best measures may also be the most simple: respect. Shattuck has heard sailors complain again and again in the course of her 12 years of shipboard studies that their berthing is loud, with shipmates switching on lights and talking without regard for those sleeping nearby.
“In some berthing spaces, they really don’t care. They’re very rude to one another,” said Shattuck, who said leadership needs to be involved to change the attitude to be more like, “‘OK, that person had to stand watch so what I really need to do is stay out of there.’ ”